Introduction

External design and hardware

Setting-up procedures and firmware upgrade

Web-interface

Command line

Testing

Summary

Introduction

Recently our testing laboratory hosted an elder brother of the testing model – the repeater RP-AC52, which functionality and performance may be unclaimed by some users. Today we decided to review the youngest model from the product line of ASUS wireless repeaters – RP-N12, supporting 802.11N wireless standard with the maximum theoretical data transmission speed equal to 300 Mbps. Okay, let’s get started.

External design and hardware

ASUS RP-N12 wireless repeater comes in a white plastic case with the dimensions of 81х55х34 mm (not considering the protruding plug and antennae). The plastic on the ribbed front panel is glossy, the name of the vendor’s company and three LEDs indicating operating of the whole device and its wired and wireless modules are located here. As the power supply unit is placed inside the case, no external adapters are required.

The upper panel is not remarkable, there are only small ventilation holes here. On the bottom panel there is a Fast Ethernet interface.

Located on the sides there are two non-detachable 2dBi antennae. The Reset and WPS buttons are also placed on one side. In addition, there is a power switch here, which allows switching off the device without unplugging it.

Connecting to a power line is carried out with the help of the plug placed on the rear panel of the case. Moreover, a sticker with brief information about the repeater is located here.

Now let's have a look at the insides of RP-N12 case.

The hardware platform of ASUS RP-N12 repeater consists of two green textolite plates, one of which serves only as a power supply unit.

The system is based on SoC processor MediaTek MT7628NN with built-in 2T2R wireless Wi-Fi module (IEEE 802.11n). Winbond 25Q32FVS1G microchip with the capacity of 4 Mbytes performs functions of flash memory. Winbond W9412G6KH-5 chip provides the repeater with 16 Mbytes of DDR RAM.

That's where we proceed to completion of the review about the hardware of ASUS RP-N12 repeater and pass directly on to studying its software capabilities.

Setting-up procedures and firmware upgrade

After switching on ASUS RP-N12 repeater one more open wireless network ASUS_RPN12 appears on the list of SSIDs available for connection. It’s worth noting that one can also connect to the device for its initial settings with the help of its Fast Ethernet interface.

Regardless of the way chosen for connecting to the device for its initial settings, one should go to 192.168.1.1 address using any modern browser, where the quick setup wizard asks to choose an existing wireless network for the connection.

If the necessary network is absent on the list, a user can perform manual setting for connection to it.

After choosing a wireless network for the connection, one should enter parameters of the network supported by the repeater itself.

When both wireless networks are chosen and set up, the device needs about two minutes for applying user settings, after that RP-N12 is absolutely ready for work.

Though the firmware upgrade for the repeater is not a necessary action, we strongly recommend installing the latest firmware version during the initial settings procedure and keeping firmware up to date further. Changing of the firmware version is performed in manual or semi-automatic mode with the help of Firmware upgrade tab, Administration menu of the web-interface.

The whole process needs about three minutes and does not require any special knowledge from users.

That’s where we draw the review of the initial settings procedure for ASUS RP-N12 repeater to a close and move on to studying the web-interface capabilities of the device.

Web-interface

The web-interface of RP-N12 repeater is typical for ASUS wireless equipment and is available to users in twelve languages. We will not describe its capabilities in detail, but mention the most interesting of them.

Right after entering correct credentials, the user is navigated to the page of Network Map item, displaying the device operation mode, wireless clients and state of the wireless network which coverage area is extended by RP-N12.

Quick Internet Setup menu item launches the primary setup wizard, which we described in the previous part of the review.

With the help of tabs of Wireless item one can manage his/her own wireless network. Here one can set parameters for MAC addresses filtering, enable the help for wireless roaming, set security parameters and enable Wi-Fi Proxy function, which allows changing MAC addresses visible in the “parent” wireless network. In more detail we described the parameters of this function in one of our previous reviews devoted to ASUS RP-AC52 repeater.

With the help of LAN menu item the administrator can change IP parameters of the repeater and also enable the built-in DHCP-server.

Operation Mode tab of Administration menu allows selecting the device operation mode: Repeater, Access Point or Media Bridge (that is a wireless client itself).

One can change the administrator password, select time zone, enable or disable a capability of the connection via Telnet protocol with the help of System tab of the same menu item. To our surprise, it is one more device where we discovered not quite correct time zone for Moscow.

One can get access to the log information with the help of the tabs of System Log item.

That's where we proceed to completion of the quick review of the web-interface capabilities for ASUS RP-N12 and pass directly on to the command line interface.

Command line

Access to the command line of the device can be enabled/disabled with the help of System tab, Administration menu item of the web-interface of the repeater.

Login and password used for the access to the command line interface are the same as for the web-interface access. ASUS RP-N12 repeater is built on Linux operating system with a kernel of version 2.6.36 using BusyBox of version 1.12.1.

RP-N12 login: admin
Password:
BusyBox v1.12.1 (2015-04-08 15:38:57 CST) built-in shell (ash)
Enter 'help' for a list of built-in commands.
# busybox
BusyBox v1.12.1 (2015-04-08 15:38:57 CST) multi-call binary
Copyright (C) 1998-2008 Erik Andersen, Rob Landley, Denys Vlasenko
and others. Licensed under GPLv2.
See source distribution for full notice.
Usage: busybox [function] [arguments]...
 or: function [arguments]...
 BusyBox is a multi-call binary that combines many common Unix
 utilities into a single executable.  Most people will create a
 link to busybox for each function they wish to use and BusyBox
 will act like whatever it was invoked as!
Currently defined functions:
 [, [[, arping, ash, basename, brctl, cat, chmod, chpasswd, cp, date, dmesg, echo, expr, free, ftpget, ftpput,
 grep, halt, hostname, ifconfig, insmod, kill, killall, klogd, ln, logger, login, logread, ls, lsmod, mdev,
 mkdir, mknod, mount, mv, ping, poweroff, ps, pwd, reboot, rm, rmmod, route, sed, sh, sleep, syslogd, telnetd,
 test, touch, traceroute, umount, unzip, vconfig, vi, wc, wget
# cat /proc/version
Linux version 2.6.36 (root@asus) (gcc version 3.4.2) #1 Wed Apr 8 15:44:07 CST 2015

With the help of ps command, let’s see what processes are currently running on the device. Unfortunately, top utility showing information on the current activity of the launched processes is absent on the device.

# ps
 PID USER       VSZ STAT COMMAND
 1 admin     2468 S    /sbin/init
 2 admin        0 SW   [kthreadd]
 3 admin        0 SW   [ksoftirqd/0]
 4 admin        0 SW   [kworker/0:0]
 5 admin        0 SW   [kworker/u:0]
 6 admin        0 SW<  [khelper]
 7 admin        0 SW   [sync_supers]
 8 admin        0 SW   [bdi-default]
 9 admin        0 SW<  [kblockd]
 10 admin        0 SW   [kswapd0]
 11 admin        0 SW   [kworker/u:1]
 14 admin        0 SW   [mtdblock0]
 15 admin        0 SW   [mtdblock1]
 16 admin        0 SW   [mtdblock2]
 17 admin        0 SW   [mtdblock3]
 18 admin        0 SW   [mtdblock4]
 19 admin        0 SW   [mtdblock5]
 20 admin        0 SW   [mtdblock6]
 21 admin        0 SW   [kworker/0:1]
 39 admin        0 SW   [RtmpCmdQTask]
 40 admin        0 SW   [RtmpWscTask]
 41 admin        0 SW   [RtmpMlmeTask]
 48 admin     2468 S    /sbin/wanduck
 50 admin     2124 S    httpd
 51 admin     1404 S    dnsmasq
 52 admin     1588 S    /usr/sbin/infosvr br0
 56 admin     2468 S    watchdog
 57 admin     2468 S    apcli_monitor
 62 admin     1280 S    lld2d br0
 313 admin     1812 S    /sbin/syslogd -m 0 -t GMT-4 -O /tmp/syslog.log
 317 admin     1812 S    /sbin/klogd
 328 admin     2464 S    ntp
 329 admin     1820 S    /bin/sh
 331 admin     1816 S    telnetd
 418 admin     1820 S    -sh
 443 admin     1816 R    ps

Now let's turn to /proc catalogue to view its contents and find out the system uptime, its average utilization, information on the CPU installed, and the amount of RAM.

# cd /proc/
# ls
455           52            18            6             fs            iomem         locks         softirqs
418           51            17            5             driver        timer_list    cmdline       kcore
331           50            16            4             tty           modules       cpuinfo       kmsg
329           48            15            3             bus           buddyinfo     devices       kpagecount
328           41            14            2             sys           pagetypeinfo  interrupts    kpageflags
317           40            11            1             irq           vmstat        loadavg       crypto
313           39            10            self          misc          zoneinfo      meminfo       diskstats
62            21            9             mounts        mtd           vmallocinfo   stat          partitions
57            20            8             net           execdomains   slabinfo      uptime        mt7628
56            19            7             sysvipc       ioports       filesystems   version       Config
# cat uptime
1769.36 1750.24
# cat loadavg
0.07 0.02 0.00 1/36 459
# cat cpuinfo
system type             : MT7628
processor               : 0
cpu model               : MIPS 24Kc V5.5
BogoMIPS                : 382.97
wait instruction        : yes
microsecond timers      : yes
tlb_entries             : 32
extra interrupt vector  : yes
hardware watchpoint     : yes, count: 4, address/irw mask: [0x0000, 0x0ff8, 0x0ffb, 0x0ff8]
ASEs implemented        : mips16 dsp
shadow register sets    : 1
core                    : 0
VCED exceptions         : not available
VCEI exceptions         : not available
# cat meminfo
MemTotal:          13864 kB
MemFree:            1112 kB
Buffers:            1152 kB
Cached:             2664 kB
SwapCached:            0 kB
Active:             2788 kB
Inactive:           2316 kB
Active(anon):        640 kB
Inactive(anon):      716 kB
Active(file):       2148 kB
Inactive(file):     1600 kB
Unevictable:          68 kB
Mlocked:               0 kB
SwapTotal:             0 kB
SwapFree:              0 kB
Dirty:                 0 kB
Writeback:             0 kB
AnonPages:          1388 kB
Mapped:              992 kB
Shmem:                 0 kB
Slab:               4748 kB
SReclaimable:        560 kB
SUnreclaim:         4188 kB
KernelStack:         288 kB
PageTables:          244 kB
NFS_Unstable:          0 kB
Bounce:                0 kB
WritebackTmp:          0 kB
CommitLimit:        6932 kB
Committed_AS:       4044 kB
VmallocTotal:    1048372 kB
VmallocUsed:        2144 kB
VmallocChunk:    1044516 kB

Contents of /bin, /sbin, /usr/bin and /usr/sbin catalogues are shown below.

# ls /bin
xtables-multi     rt2860apd         mount             lld2d             hostname          cp
vi                rm                mknod             kill              grep              chmod
umount            reg               mkdir             iwpriv            gpio              cat
touch             pwd               mii_mgr_cl45      iwconfig          flash             busybox
sleep             ps                mii_mgr           iptables-restore  echo              ated
sh                ping              ls                iptables          dnsmasq           ash
sed               mv                login             igmpproxy.sh      dmesg
rtinicapd         mtd_write         ln                igmpproxy         date
# ls /sbin
wps_stop               wan-down               restart_dhcpd          logread                init
wps_start              vconfig                reboot                 logmessage             ifconfig
wps_oob                track_set              re_wpsc                link_up                halt
webs_upgrade_radio.sh  syslogd                rc                     link_status            gen_ralink_config
webs_upgrade.sh        start_telnetd          poweroff               link_down              detectWAN_arp
webs_update.sh         run_telnetd            nvram_oob              klogd                  ddns_updated
watchdog               route                  ntp                    ip-up                  apcli_monitor
wanduck                rmmod                  mdev                   ip-down                ATE
wan-up                 restart_dns            lsmod                  insmod
# ls /usr/bin
wget        unzip       test        killall     ftpget      expr        arping      [
wc          traceroute  logger      ftpput      free        basename    [[
# ls /usr/sbin
udhcpc      tcpcheck    ntpclient   infosvr     chpasswd
telnetd     nvram       networkmap  httpd       brctl

We can't help mentioning nvram utility that allows changing certain important device operation parameters.

# nvram
Usage: nvram [get name] [set name=value] [unset name] [commit] [show] [restore file] [save file]
# nvram show | grep admin
http_username=admin
http_passwd=admin
size: 8825 bytes (52615 left)

That is where we bring the brief review of the repeater command line interface capabilities to a close and pass on to testing the device, because, in contrast to its elder brother RP-AC52, the repeater under review does not support any multimedia functions.

Testing

The first measurements we usually start this section with are estimating the booting time of the repeater, which is a time interval starting with the moment when the power is on until the first echo reply is received through ICMP. ASUS RP-N12 repeater boots in 17 seconds. We consider this result normal.

The second traditional test is a security scanning procedure, performing with the help of a security scanner Positive Technologies XSpider 7.7 (Demo build 3100). There were four open ports discovered. The most interesting discovered data are presented below.

Before getting down to performance tests we would like to get our readers familiar with the main parameters of the test stand we used.

 Component PC Notebook
 Motherboard ASUS Maximus VI Extreme ASUS M60J 
 CPU  Intel Core i7 4790K 4 ГГц Intel Core i7 720QM 1.6 ГГц
 RAM  DDR3 PC3-10700 SEC 32 Гбайта DDR3 PC3-10700 SEC 16 Гбайт
 NIC Intel PRO/1000 PT
 ASUS PCE-AC68
Atheros AR8131
ASUS RT-AC66U 
 OS Windows 7 x64 SP1 Rus  Windows 7 x64 SP1 Rus 

 

We decided to find out the performance of RP-N12 for each of three supported operation modes. At first, we measured throughput for one, five and fifteen simultaneous TCP connections during the device operating in Media Bridge mode. This mode is very similar to the wireless client mode, when RP-N12 connects to an existing wireless network.

In addition to Media Bridge mode ASUS RP-N12 can perform functions of an access point. The device throughput in this mode is presented at the diagram below.

Finally, we got to the most interesting part – RP-N12 throughput in the repeater mode. In this mode the device connects to one wireless network and creates the second one.

That's where we draw the testing part to a close and move on to summing it all up.

Summary

ASUS RP-N12 wireless repeater showed itself as a reliable medium-grade device, which can satisfy needs of ordinary users in the coverage area of the wireless network. External design and compact dimensions allow installing the device in sight.

The strength areas of ASUS RP-N12 are listed below.

  • Compact dimensions and accurate external design
  • Support of Wi-Fi Proxy functionality
  • Support of several operation modes (Media Bridge, Repeater, Access Point)
  • Sufficient  performance of the wireless module

Unfortunately, we cannot help but mention discovered drawbacks of the device.

  • The web-interface is not completely translated
  • Incorrect time zones

When this review was being written, the expected retail price of ASUS RP-N12 in Russia was 2290 roubles.

Introduction

External design and hardware

Firmware upgrade

Web-interface

Testing

Summary

Introduction

Our test lab already hosted routers that supported Smart Connect. This feature allows for the automatic redistribution of wireless clients between the supported wireless networks for improved efficiency in bandwidth usage. Read more below about this and a couple of other things that will pleasantly surprise users of D-Link DIR-890L wireless router.

External design and hardware

D-Link DIR-890L wireless router looks like a high-tech flying machine from the future that landed on the table just for a several seconds before taking off again. The device has the dimensions of 387х248х120mm and the weight of one kilo. The device needs an external power source with the following characteristics (included in the box) for functioning: 12V and 5А.

It's hard to understand where the top panel and side panels are because the device has a peculiar shape. It's worth mentioning that DIR-890L has six external non-detachable antennae that are installed on the case edges and rear panel.

The top panel edge has LEDs showing the power and Internet connectivity, wireless module activity, and USB port usage located on it.

The device is meant for both desk and wall mounting and that is why its bottom panel has not only the rubber legs but two tooling holes too. One will also be able to find a sticker with brief information about the device here. The biggest part of the bottom panel is a ventilation grate.

There are a ventilation grate and the brand logo located on the rear panel of the router. Apart from it, there are also four LAN and one WAN Gigabit Ethernet ports, power socket with ON/OFF button, Reset and WPS buttons, and two USB ports, USB 2.0 and USB 3.0.

Now let's have a look at the insides of the case.

All electronic stuffing of D-Link DIR-890L wireless router is one green textolite card which has all the essential elements located on both of its sides. The biggest part of the card surface is covered by detachable heatsinks. Unfortunately, all primary elements are covered with metal screens of smaller size.

Unfortunately, the only module accessible for inspection was the flash memory Macronix MX25L25635FMI-10G module with the size of 32 Mbytes.

Now let's pass on to reviewing of the software capabilities of DIR 890-L.

Firmware upgrade

In order to change the firmware version one needs to use Upgrade item in Management menu. Firmware upgrade may be carried out both in a manual and semi-automatic mode. Obviously, firmware upgrade in the semi-automatic mode is available only if the router is connected to the Internet. Upon manual firmware upgrade the administrator will need to download the firmware upgrade file beforehand and then upload it to the device.

Irrespective of the chosen firmware upgrade method, the process won't require any special skills from the administrator. The whole upgrade procedure takes about three minutes (not considering the firmware download time).

Apart from the original firmware, one can install alternative firmware on DIR-890L model; DD-WRT firmware is one of them. The administrator can change to DD-WRT firmware in two steps: at first upgrade the firmware to an interim release of DD-WRT using factory-to-ddwrt.bin file and then use dir890-webflash.bin file that contains the firmware full version.

After booting the router with the installed firmware interim release, the administrator will need to specify his/her username and password.

After that the administrator will be gained access to the web-interface of the interim firmware where s/he can select the language using Management tab in Administration menu. However, reviewing all other capabilities of the alternative firmware falls far beyond the scope of this article.

One will need to use Upgrade tab in Administration menu in order to change to the full version of DD-WRT firmware. The upgrade procedure is quite common.

The whole firmware upgrade process up to the full DD-WRT version takes less than ten minutes and does not require any technical proficiency from the administrator.

Switching back to the factory defaults is a bit more complicate: one will need to change the router to the recovery mode and use the web-server built-in in the bootloader to upload the right firmware upgrade file to the device. DIR-890L router can be switched to the recovery mode by holding down Reset button while the device is turning on and for 3-5 seconds after it. A router in the recovery mode can be spotted by the slowly flashing power LED on the front panel. At this moment only the bootloader is active. The active bootloader answers the echo requests from ICMP using IP packets with the value of TTL=100. Upon the booting has been finished completely, the packets will contain TTL=64. It's also worth mentioning that the bootloader is always assigned 192.168.0.1/24 address on a LAN interface.

That is where we bring a brief review of issues associated with the firmware upgrade process of the device to a conclusion and pass on to examining capabilities of D-Link DIR-890L wireless router web-interface.

Web-interface

Any modern web-browser may be used in order to access and manage the device web-interface. One will need to specify the administrator password to get access to it. The web-interface is available in ten languages. We believe that the possibility of choosing the web-interface language before actually logging in is very useful. However, the administrator won't be able to select another language after logging in. Apart from it, the fact that the login page contains certain information about the used firmware really surprised us. We think that this kind of information should be accessible only following the successful user authentication due to security reasons.

Upon successful authentication the administrator will find him/herself on the home page of the device. Over here one can check the Internet connectivity, review the list of the connected clients and devices fitted with a USB interface, and overview certain information about the router operation.

We wouldn't call the functionality of DIR-890L, a flagship device by D-Link, really wide. All settings are located in three menus: Settings, Features, and Management. Let's have a closer look at every menu.

One can use a special wizard for performing the initial setup of the router. It's located in Wizard manual item in Settings menu.

Management of access to the WAN is done using tabs in Internet item. The administrator can choose the device operation mode over here too: router or access point. Apart from connection to the web using the current version of IP, IPv4, the router supports connections via IPv6 too.

Wireless item is used for management of the wireless network. Over here the user enable and disable Smart-Connect feature and manage wireless guest networks.

Network item is used for management of local network parameters.

Access to the data stored on an external data carrier with USB interface can be gained using various protocols. These settings are available in SharePort item, Settings menu.

In order to manage the router remotely using a tablet or smartphone one will need to sign up in mydlink service and use their app. The applicable settings are available in the same-named menu item.

One can manage traffic prioritization using QoS Engine item, Features menu.

Firewall Settings item is used for forwarding or blocking certain types of traffic.

Port Forwarding item is used in case if a server located in the local network must be accessed from the Internet.

Website Filter item is used to deny access to certain resources in the Internet to the local network users.

Management of static routes is done using Static Routes item. One can specify routes both for IPv4 and IPv6. However, it's worth mentioning that upon creation of an IPv4 route the user will only be able to use the WAN port as the output interface.

Dynamic DNS item will come in handy in case if the service provider offers its users real but dynamic addresses.

D-Link DIR-890L wireless router can also perform functions of a VPN server; one can manage the corresponding settings in Quick VPN item in Features menu. However, it's worth noticing that only one type of tunnel connections, L2TP over IPSec, is supported.

Time sync parameters are located in Time item in Management menu. One can manage feature scheduling in this item, too.

The log information can be sent to a remote server using Syslog and SMTP protocols, the respective settings are located in System Log item. It's strange but we couldn't review these data locally.

Management of user authentication and equipment configuration parameters is done using Admin and System items.

Statistics item offers the user information about the current utilization of wired and wireless interfaces of the router.

That's where we proceed to completion of the review of D-Link DIR-890L wireless router web-interface capabilities and pass directly on to testing it.

Testing

The first testing procedure we usually begin our testing section with is estimating the booting time of the device, which is a time interval starting with the moment when the power is on until the first echo reply is received through ICMP. D-Link DIR-890L wireless router boots in 53 seconds. We believe that the result is decent.

The second test, which is no less traditional, was a security scanning procedure carried out using Positive Technologies XSpider 7.8 utility. On the whole, there were 13 open ports discovered. The most interesting data are presented below.

 

Before getting straight down to performance tests we would like to mention the key specifications of the test stand we used.

Component PC Notebook
Motherboard ASUS Maximus VI Extreme ASUS M60J
CPU Intel Core i7 4790K 4 GHz Intel Core i7 720QM 1.6 GHz
RAM DDR3 PC3-10700 SEC 32 Gbytes DDR3 PC3-10700 SEC 16 Gbytes
NIC Intel PRO/1000 PT
ASUS PCE-AC68
Atheros AR8131
OS Windows 7 x64 SP1 Rus Windows 7 x64 SP1 Rus

At first we decided to find out how DIR-890L handles performing of NAT/PAT translations. As it was expected, we received decent routing speeds.

For those users who live in the ex-Soviet bloc countries it's still important to have a router that performs well upon operation with various VPN connections that the service providers use to provide access to the Internet. The diagram presented below shows the performance of DIR-890L operating with PPTP.

The model under review also has a built-in VPN server that uses L2TP over IPSec protocol. However, it would be fair to mention that various firmware meant for devices used in Russia and other countries only have support of limited cryptoalgorithm versions. This makes it impossible to get connected to the device of a common VPN client built-in in the modern Microsoft Windows OSes without performing a deep reconfiguration of the OS. Since our test lab website is read not only by the users from Russia, we asked the vendor to provide us with the firmware that has the full support of cryptography. Results of the measurements of D-Link DIR-890L performance with an established L2TP over IPSec connection are presented below. The received speeds cannot be considered high. It also came as a surprise to us that the built-in VPN server doesn't support any other protocols like PPTP or OpenVPN.

Apart from support of the current version of IP, IPv4, the wireless router under review also has support of the newer protocol version, IPv6. The diagram below shows the device performance upon operation with this protocol.

One of the most anticipated tests is, we dare say, measuring the performance of the wireless segment. At first we found out what speeds the users of a 2.4 GHz wireless network should expect to see. These speed values cannot be considered high, which is probably associated with DIR-890L detecting other wireless networks during the tests and decreasing the channel bandwidth from 40 MHz down to 20 MHz. It's not possible to specify the fixed channel bandwidth of 40 MHz using the device web-interface. Currently 2.4 GHz frequency range is heavily loaded in big cities and that's why we believe that clients who prefer quality of service would gradually switch to 5 GHz wireless range.

The diagrams presented below show results of the performance measurements of the wireless network within the frequency range of 5 GHz. We used two wireless clients in order to measure user data transfer speeds in the above-mentioned range: ASUS PCE-AC68 and a NIC that comes together with ASUS Maximum V Extreme motherboard.

Receiving the highest possible performance upon using the second client was not our aim. Actually, we wanted to see the extent of mutual influence between the high-speed client and the low-speed client. At first we connected the wireless clients to different wireless networks operating in 5 GHz frequency range; naturally, we disabled Smart-Connect feature beforehand. After that we made the same measurements when both of the clients were connected to the same wireless network.

As one can see on the diagram with the total of transfer speeds of two clients above, the mutual influence of the clients is extremely high. This is why we would like to recommend the users of D-Link DIR-890L to connect high-speed and low-speed clients to different wireless networks. Smart Connect feature lets dynamically distribute clients between the wireless networks. And though we didn't find any settings associated with this feature in the device web-interface, we decided to measure the user data transfer speeds using two wireless clients with enabled Smart-Connect feature that are getting connected to DIR-890L.

The results turned out not too good, but the speeds were higher than in the case where both clients used the same network. According to our data, one of the clients used 2.4 GHz frequency range and the other one used 5 GHz range. Unfortunately, the router software doesn't provide any tools for monitoring of the connected wireless clients and it's impossible to find out what frequency range is used by what client without special-purpose equipment or software.

Neither did we keep away from the possibility to connect external USB data carriers. Unfortunately, D-Link DIR-890L only supports two file systems: NTFS and FAT32. The diagrams below show results of the measurements of access speeds to the data stored on external data carriers connected to the USB 2.0 and 3.0 ports. In this test we used Intel NASPT 1.7.1 utility and our external 256 GB Transcend TS256GESD400K SSD.

That's where we draw the testing chapter to a close and move on to summing it all up. The last thing we'd like to mention is the results of a quite traditional test for us, measuring the device case temperature. The router case temperature didn't grow higher than 43°С or 109,4° F upon the ambient temperature of 24°С or 75,2° F.

Summary

We were left with mixed feelings after reviewing D-Link DIR-890L wireless router. On one hand, the device is fitted with a powerful hardware platform and supports three wireless frequency ranges, but on the other hand the current firmware version makes it impossible to unleash the device potential fully. We hope that the vendor deals with the issues we discovered in the next firmware version.

Among the strength areas of D-Link DIR-890L wireless router are the following.

  • Support of three independent radios in two frequency ranges (tri-band)
  • Ability to create wireless guest networks
  • Availability of Smart-Connect feature
  • High performance CPU
  • Support of wireless guest networks
  • USB ports
  • Support of IPv6
  • Good access speeds to the data which are stored on an external HDD
  • Availability of a built-in VPN server (L2TP over IPSec)

Unfortunately, we cannot help but mention certain drawbacks we have discovered.

  • Low performance in 2.4 GHz frequency range
  • Absence of certain important features in the web-interface
  • Low performance of the built-in VPN server
  • Absence of support of EXT2/3/4 file systems
  • High price

Our test lab team couldn't come to the shared conclusion about whether the peculiar device case design is a positive or negative quality and that's why we didn't include the efforts of D-Link's designers in either of the lists above.

As of when this article was being written, the average price for a D-Link DIR-890L in Moscow online shops was 19770 roubles.

Introduction

External design and hardware

Firmware update

Web-interface

Command line interface

Testing

Conclusion

Introduction

More than half a year passed since our test lab hosted equipment by D-Link company. Did you miss the reviews of their new models? Welcome a DIR-825AC wireless router with Gigabit interfaces, USB 2.0 port, and AC1200 wireless module.

External design and hardware

D-Link DIR-825AC wireless router comes in a black plastic case with the dimensions of 195x155x35mm and the weight of only 250 grams. The device needs an external power source with the following characteristics (included in the box) for functioning: 12V and 1.5А.

The best part of the upper panel of the router is glossy. There are LEDs indicating status of the entire device as well as those of its user ports and wireless module located on it.

On the front panel of the case there is a WPS button that facilitates connection of wireless clients and enables/disables the wireless module.

Side panels are not remarkable at all and there is only a ventilation grate located on them.

On the perforated bottom of the router there are four rubber legs and a sticker with brief information about the device. Also, there are two mounting holes used for wall mounting of the device.

Two non-detachable antennae are located on the rear panel of the case. Apart from them, there are five Gigabit Ethernet ports (1 WAN and 4 LANs), USB 2.0 port, ON/OFF button, power socket, and sunken Reset button located over here.

Now let's have a look at the insides of the case. The electronic stuffing of D-Link DIR-825 wireless router is one green textolite card which has all essential elements located on one of its sides.

There is Realtek RTL8197DN microchip, which runs at 660 MHz and acts as the SoC CPU, located under the radiator. Two chips produced by the same vendor answer for support of the wireless network: RTL8192ER and RTL8812AR. It's worth noticing that the same hardware platform is used in Upvel UR-825AC router. The system is fitted with a DDR2 64 Mbyte RAM module powered by Nanya NT5TU32M16EG-AC microchip. Support of the wired network segment is performed by Realtek RTL8367RB managed switch that has five Gigabit Ethernet physical ports.

That is where we bring the review of the hardware platform of D-Link DIR-825 wireless router to a conclusion and pass on to examining capabilities of its software component.

Firmware update

Firmware upgrade is carried out in Firmware Upgrade section, System group of the router web-interface. The firmware upgrade can be carried out both in manual and semi-automatic modes and doesn't require any technical experience from the user.

Upon upgrading the firmware in the semi-automatic mode the wireless router will automatically connect to the vendor's servers and download the new firmware version. Naturally, in order to perform this step one needs to be connected to the Internet. Firmware upgrade in the manual mode is only a bit more difficult. One simply needs to download the file containing the new firmware version and upload it to the wireless router. The whole upgrade process takes a bit more than six minutes.

That is where we bring this short section dedicated to the firmware upgrade process to a conclusion and pass on to examining capabilities of the device web-interface.

Web-interface

D-Link DIR-825 web-interface is different from the one we are accustomed to from the previous reviews, but still we will not review all of its capabilities in detail, but focus on the most interesting ones. The device web-interface is available in seven languages. Upon successful authentication the user will find him/herself on Information page, Home group in the web-interface menu.

Other sections in Home group are used to launch various wizards that can help the first-time user to significantly reduce the device set-up time.

Monitoring group contains brief information about the settings and current device status.

Sections in Status group feature varied statistics as well as data on the active sessions, connected clients, existing subscriptions for the group traffic, and so on.

LAN and WAN settings are located in Net group. A really nice option that the device possesses is the capability of connection to not only wired service providers using PPTP, PPPoE, and L2TP tunnels with either dynamic or static addresses, but also to wireless providers using an external 3G or LTE modem.

Wi-Fi group contains settings associated with the wireless network. We just cannot help it but mention that upon selecting the wireless channel the user will be shown information about the current usage of channels. Indeed, the life gets really sad with the 2.4 GHz channel workload in the centre of Moscow. Another helpful feature is that D-Link DIR-825 wireless router can act as a wireless client, allowing connection to the wireless networks in range.

The device under review supports VLAN too and the corresponding settings are available in the same-named section in Advanced group.

Using Redirect section in the same group the administrator can specify cases in which the router can send out messages about redirecting the traffic to other devices.

Settings of static routing for IPv4 and IPv6 can be managed using Routing and IPv6 routing sections in Advanced group.

The fact that the device supports IPSec tunnels, which can be managed in IPsec section in the same group, stroke us as a bit strange.

Management of virtual servers and various filtration rules is done using sections in Firewall group. In order to manage URL filtration one will need to use Control group.

At this point we would like to point out that the filtration of access to various content may be performed not only in the manual mode, but automatically too, which is done via Yandex.DNS service that filters the resources by URL. Configuring of the router operation parameters with the above-mentioned service is done using sections in Yandex.DNS group.

Sections in 3G/LTE modem group are meant for managing the external USB modem in order to connect to mobile networks.

The USB port can be used not only for connection of the modem but the flash card, external HDD, or even printer too. Management of printers and data access protocols located on the external drives is done via sections in USB storage group.

Settings of the built-in torrent client are changed using Transmission group.

Sections located in System group are used for managing the device configuration files, changing administrator password, reviewing log information, upgrading the firmware, setting the system time, managing the users that have access to the data stored on the external USB storage, and finally checking the availability of the remote hosts.

However there's yet another peculiarity in the web-interface operation that we would like to expound on. All settings made by the user in the router settings are not saved automatically. In other words, after the device initial set-up has been made, one will need to literally save the settings. This can seem a bit confusing to the beginner users, but still we believe that it may be useful if someone is configuring the router remotely. In cases like these, one only needs to reboot the device in order to cancel the wrong changes in the settings.

That is where we bring a brief review of D-Link DIR-825 wireless router web-interface capabilities to a conclusion and pass on to examining capabilities of its command line.

Command line interface

Switching the access to the command line of D-Link DIR-825 router on and off is performed using Telnet section in System group of the device web-interface.

In order to access the command line one must use the same log-on information as for the connection to the device web-interface. BusyBox 1.19.2 library is installed in Linux with a pretty outdated 2.6.30.9 core on DIR-825AC router.

Dlink-Router login: admin
Password:
Welcome to
 _______          ___     __  ____   _  _   ___
 |  ___  \        |   |   |__||    \ | || | /  /
 | |   | ||  ___  |   |__  __ |     \| || |/  /
 | |___| || |___| |      ||  || |\     ||     \
 |_______/        |______||__||_| \____||_|\___\
 = Building Networks for People =
BusyBox v1.19.2 (2014-10-17 18:41:43 MSK) built-in shell (ash)
Enter 'help' for a list of built-in commands.
$ cat /proc/version
Linux version 2.6.30.9 (builder@rd) (gcc version 4.4.5-1.5.5p4 (GCC) ) #1 Fri Oct 17 18:37:40 MSK 2014
$ busybox
BusyBox v1.19.2 (2014-10-17 18:41:43 MSK) multi-call binary.
Copyright (C) 1998-2011 Erik Andersen, Rob Landley, Denys Vlasenko
and others. Licensed under GPLv2.
See source distribution for full notice.
Usage: busybox [function] [arguments]...
 or: busybox --list[-full]
 or: function [arguments]...
 BusyBox is a multi-call binary that combines many common Unix
 utilities into a single executable.  Most people will create a
 link to busybox for each function they wish to use and BusyBox
 will act like whatever it was invoked as.
Currently defined functions:
 [, [[, addgroup, adduser, ash, basename, brctl, cat, chgrp, cp, crond, crontab, date, dd, delgroup, deluser,
 echo, false, free, grep, gunzip, gzip, halt, hexdump, httpd, ifconfig, insmod, kill, killall, klogd, ln,
 logger, login, logread, ls, lsmod, md5sum, mkdir, mount, nc, nice, nslookup, ntpd, passwd, ping, ping6, pmap,
 poweroff, ps, reboot, renice, rm, rmmod, route, sh, sleep, syslogd, tail, tar, telnetd, test, top, touch,
 traceroute, traceroute6, true, umount, zcat

Let's see what processes are currently running on the device using ps command. By using top utility one can obtain information on the current activity of the launched processes.

$ ps
 PID USER       VSZ STAT COMMAND
 1 admin     1816 S    /sbin/init
 2 admin        0 SW<  [kthreadd]
 3 admin        0 SW<  [ksoftirqd/0]
 4 admin        0 SW<  [events/0]
 5 admin        0 SW<  [khelper]
 8 admin        0 SW<  [async/mgr]
 124 admin        0 SW<  [kblockd/0]
 134 admin        0 SW<  [khubd]
 151 admin        0 SW   [pdflush]
 152 admin        0 SW<  [kswapd0]
 153 admin        0 SW<  [crypto/0]
 730 admin        0 SW<  [mtdblockd]
 802 admin     2616 S    resident[mngr]: building networks for people...
 936 admin      740 S    /usr/sbin/link_watcher 0
 938 admin     1188 S    klogd
 940 admin     1224 S    syslogd -S -m 0 -C32 -l 7 -L
 1033 admin     1676 S    yasslews /tmp/yasslews.conf
 1034 admin     1108 S    yasslews /tmp/http_srv_redirect.conf
 1036 admin     1196 R    telnetd -p 23
 1038 admin     1108 S    yasslews /tmp/http_srv_redirect.conf
 1039 admin     1108 S    yasslews /tmp/http_srv_redirect.conf
 1040 admin     1108 S    yasslews /tmp/http_srv_redirect.conf
 1041 admin     1108 S    yasslews /tmp/http_srv_redirect.conf
 1044 admin     1676 S    yasslews /tmp/yasslews.conf
 1045 admin     1676 S    yasslews /tmp/yasslews.conf
 1046 admin     1676 S    yasslews /tmp/yasslews.conf
 1047 admin     1676 S    yasslews /tmp/yasslews.conf
 1048 admin     1676 S    yasslews /tmp/yasslews.conf
 1049 admin     1676 S    yasslews /tmp/yasslews.conf
 1051 admin     2448 S    tr069
 1374 admin     3224 S    racoon -f /tmp/racoon.conf -l /var/log/racoon.log
 1376 admin     1028 S    miniupnpd -f /tmp/miniupnpd.conf
 1386 nobody    1004 S    dnsmasq --keep-in-foreground --conf-file=/tmp/dnsmas
 1394 admin     2636 S    resident[wrkr]: waiting for something...
 1399 admin      996 S    dnsmasq --keep-in-foreground --conf-file=/tmp/dnsmas
 1613 admin     1196 R    -sh
 1657 admin     1196 R    ps
Mem: 26300K used, 22120K free, 0K shrd, 3080K buff, 9712K cached
CPU:   0% usr   0% sys   0% nic 100% idle   0% io   0% irq   0% sirq
Load average: 0.00 0.05 0.03 1/37 1658
 PID  PPID USER     STAT   VSZ %VSZ %CPU COMMAND
 1374     1 admin    S     3224   7%   0% racoon -f /tmp/racoon.conf -l /var/lo
 1394   802 admin    S     2636   5%   0% resident[wrkr]: waiting for something
 802     1 admin    S     2616   5%   0% resident[mngr]: building networks for
 1051     1 admin    S     2448   5%   0% tr069
 1     0 admin    S     1816   4%   0% /sbin/init
 1047  1044 admin    S     1676   3%   0% yasslews /tmp/yasslews.conf
 1049  1044 admin    S     1676   3%   0% yasslews /tmp/yasslews.conf
 1048  1044 admin    S     1676   3%   0% yasslews /tmp/yasslews.conf
 1046  1044 admin    S     1676   3%   0% yasslews /tmp/yasslews.conf
 1033     1 admin    S     1676   3%   0% yasslews /tmp/yasslews.conf
 1044  1033 admin    S     1676   3%   0% yasslews /tmp/yasslews.conf
 1045  1044 admin    S     1676   3%   0% yasslews /tmp/yasslews.conf
 940     1 admin    S     1224   3%   0% syslogd -S -m 0 -C32 -l 7 -L
 1613  1036 admin    S     1196   2%   0% -sh
 1036     1 admin    S     1196   2%   0% telnetd -p 23
 1658  1613 admin    R     1196   2%   0% top
 938     1 admin    S     1188   2%   0% klogd
 1034     1 admin    S     1108   2%   0% yasslews /tmp/http_srv_redirect.conf
 1038  1034 admin    S     1108   2%   0% yasslews /tmp/http_srv_redirect.conf
 1040  1038 admin    S     1108   2%   0% yasslews /tmp/http_srv_redirect.conf

Now let's turn to /proc catalogue to view its contents and find out the system uptime, its average utilisation, information on the CPU installed, and the amount of RAM.

$ pwd
/proc
$ ls
1675                  152                   buddyinfo             rf_switch             gc_overflow_timout
1613                  151                   pagetypeinfo          watchdog_reboot       alg
1399                  134                   vmstat                wlan0                 hw_nat
1394                  124                   zoneinfo              wlan0-vxd             url_filter
1386                  8                     vmallocinfo           wlan0-va0             qos
1376                  5                     slabinfo              wlan0-va1             br_wlanblock
1374                  4                     filesystems           wlan0-va2             br_igmpsnoop
1051                  3                     locks                 wlan0-va3             br_igmpDb
1049                  2                     cmdline               wlan1                 br_mCastFastFwd
1048                  1                     cpuinfo               wlan1-vxd             br_igmpVersion
1047                  self                  devices               wlan1-va0             br_igmpquery
1046                  mounts                interrupts            wlan1-va1             br_igmpQuerierInfo
1045                  net                   loadavg               wlan1-va2             br_mldQuerierInfo
1044                  sysvipc               meminfo               wlan1-va3             br_mldVersion
1041                  fs                    stat                  custom_Passthru_wlan  br_mldquery
1040                  driver                uptime                rtl865x               br_igmpProxy
1039                  tty                   version               eth0                  enable_dos
1038                  bus                   kcore                 eth1                  filter_table
1036                  sys                   kmsg                  custom_Passthru       fast_pptp
1034                  irq                   kpagecount            peth0                 pptp_conn_ck
1033                  misc                  kpageflags            StormCtrl             fast_l2tp
940                   scsi                  crypto                eee                   fast_hello_reply
938                   execdomains           diskstats             phyRegTest            fast_pppoe
936                   ioports               partitions            br_mldsnoop           fast_nat
802                   iomem                 gpio                  reInitSwitchCore
730                   timer_list            usb_mode_detect       mtd
153                   modules               load_default          suspend_check
$ cat uptime
507.83 473.94
$ cat loadavg
0.00 0.03 0.02 3/40 1681
$ cat cpuinfo
system type             : RTL819xD
processor               : 0
cpu model               : 56322
BogoMIPS                : 658.63
hardware watchpoint     : no
tlb_entries             : 32
mips16 implemented      : yes
$ cat meminfo
MemTotal:          48420 kB
MemFree:           22132 kB
Buffers:            3080 kB
Cached:             9716 kB
SwapCached:            0 kB
Active:             5340 kB
Inactive:           9532 kB
Active(anon):       2076 kB
Inactive(anon):        0 kB
Active(file):       3264 kB
Inactive(file):     9532 kB
SwapTotal:             0 kB
SwapFree:              0 kB
Dirty:                 0 kB
Writeback:             0 kB
AnonPages:          2088 kB
Mapped:             2140 kB
Slab:              10000 kB
SReclaimable:        684 kB
SUnreclaim:         9316 kB
PageTables:          232 kB
NFS_Unstable:          0 kB
Bounce:                0 kB
WritebackTmp:          0 kB
CommitLimit:       24208 kB
Committed_AS:       4400 kB
VmallocTotal:    1048404 kB
VmallocUsed:        1040 kB
VmallocChunk:    1039536 kB

Let's find out what kind of content /bin, /sbin, /usr/bin, and /usr/sbin catalogues have.

$ ls /bin
zcat            sh              ping            l2tpd           iapp            dd              adduser
wscd            rm              odhcp6c_script  kill            gzip            date            addgroup
urlfilterd      resident_cli    nice            iwpriv          gunzip          cp              3gcli
umount          resident        mount           iwlist          grep            chgrp
uboot.img       ps              modprobe        iwcontrol       false           chat
true            pptp            mkdir           iwconfig        echo            cat
touch           pppoe-relay     ls              ip              dnsmasq_script  busybox
tar             pppd            login           initdongle      deluser         auth
sleep           ping6           ln              igmpx           delgroup        ash
$ ls /sbin
wpa_supplicant  syslogd         poweroff        lsmod           insmod          halt
wpa_passphrase  route           mount.ntfs-3g   logread         init            event
wpa_cli         rmmod           miniupnpd       led_test        ifconfig        dcfg
tr069           reboot          mfc             klogd           hotplug         button_test
$ ls /usr/bin
yasslews             sqlite3              plainrsa-gen         logger               cyassl-config
udhcpc               smbpasswd            passwd               libusb-config        crontab
transmission-daemon  smbd                 odhcp6c              killall              basename
traceroute6          setkey               nslookup             iptables-xml         [[
traceroute           renice               nmbd                 inadyn               [
top                  racoonctl            nc                   hexdump
test                 racoon               mtd_write            free
tail                 pmap                 md5sum               event_rpcgen.py
$ ls /usr/sbin
zebra              ripd               notify_all         iptables-restore   ip6tables-multi    crond
vconfig            pure-ftpd          minidlnad          iptables-multi     ip6tables          brctl
usb_modeswitch     p910nd             madwimax           iptables           httpd              arptables
test4g             ntpd               link_watcher       ip6tables-save     drop_caches
telnetd            ntfs-3g            iptables-save      ip6tables-restore  dnsmasq

Information on the current firmware version is located in /VERSION file.

$ cat VERSION
NAME:           DIR_825AC
VERSION:        2.5.23
SYSBUILDTIME:   Fri Oct 17 18:44:53 MSK 2014
VENDOR: D-Link Russia
BUGS:           <
 This email address is being protected from spambots. You need JavaScript enabled to view it.;
SUMMARY:        Root filesystem image for DIR_825AC

That is where we bring a brief review of the router command line to a conclusion and pass directly on to testing it.

Testing

The first testing procedure we usually begin our testing section with is estimating the booting time of the device, which is a time interval starting with the moment when the power is on until the first echo reply is received through ICMP. D-Link DIR-825AC wireless router boots in 41 seconds. We believe that the result is decent.

The second traditional test was a security scanning procedure, which has been carried out using Positive Technologies XSpider 7.7 (Demo build 3100) utility. On the whole, there were ten open ports discovered. The most interesting data are presented below.

Before getting down to performance tests we would like to get our readers familiar with the key specifications of the test stand we used.

Component PC Notebook
Motherboard ASUS Maximus VI Extreme ASUS M60J
CPU Intel Core i7 4790K 4 GHz Intel Core i7 720QM 1.6 GHz
RAM DDR3 PC3-10700 SEC 32 Gbytes DDR3 PC3-10700 SEC 16 Gbytes
NIC Intel PRO/1000 PT
ASUS PCE-AC68
Atheros AR8131
OS Windows 7 x64 SP1 Rus Windows 7 x64 SP1 Rus

 

We decided to begin the throughput tests by measuring routing speeds upon execution of NAT/PAT translations and without it. The tests were carried out with 1, 5, and 15 concurrent TCP sessions.

 

Connection to service providers functioning in the ex-Soviet Union countries is still carried out via various tunnels. And probably one of the most popular technologies is PPTP. As a matter of course, we couldn't help but measure the performance of D-Link DIR-825AC router upon operation with these tunnels.

As soon as all tests had been carried out and the review had been finished, we received a letter from the vendor telling us that the speeds we received for PPTP are too low. The vendor's measurements show the figures that are twice as high. We tried to puzzle out why this happened with our test stand. Everything turned out to be really easy. In our case the tunnel support was carried out by a host where Microsoft Windows OS was installed. Windows enables MPPC compression to PPTP tunnels by default and the router resources were simply not enough for performing high-speed compression. This led to the decrease in performance. It looks like the compression on the test stands of the vendor was disabled. We performed this test once more by disabling MPPC (by specifying nomppc parameter in Extra options field in settings of the VPN connection of DIR-825AC). After that the speed increased to the same values received by the vendor. That's why we recommend people that use high-speed plans to disable the compression for tunnel connections. Results of the measurements are presented below.

We believe that PPTP tunnels are more resource-intensive than the rest. In other words, users may see even higher speeds upon using L2TP and PPPoE tunnels.

DIR-825AC wireless router supports operation not only with the current IP version, IPv4, but also with the new one, IPv6. Measurement results of the data transmission speeds using IPv6 are presented on the diagram below.

IPSec tunnels with various encryption and authentication protocols may be used in order to connect two local networks of the user. We decided to test the device performance upon operation with IPSec tunnels with AES encryption. In order to do this we asked the vendor to provide us with another DIR-825AC router.

It's worth mentioning that D-Link company is actively refining the support of this protocol by its routers. For example, in the next firmware version users will see many other features that they will be able to adjust upon setting-up of IPSec. But keep schtum! This is a secret!

Since the device under review has a USB 2.0 port, we decided to measure the access speed to the user data located on an external data storage connected to the USB interface. In order to carry out this testing procedure we used our standard 750 Gbytes Transcend StoreJet 25M3 hard disk, which we successively formatted into three file systems: NTFS, EXT3, and FAT32. Results of the measurements are presented on the diagram below.

One of the most interesting tests in this chapter is, we dare say, the measurements of performance of the wireless segment. One can find the results of speed measurements we received for the data for every of the two frequency ranges on the diagram below.

Now it's high time to sum it all up!

Conclusion

Generally, we are glad about D-Link DIR-825AC wireless router we tested. We believe that this is a good entry-level device that can meet all essential needs of the majority of users. PPTP connection speeds will be enough for almost all possible service plans of the majority of providers, whilst the capability of 3G/LTE modem connection to the USB port won't let you go offline if the wired service provider is having some internal problems.

The strength areas of D-Link DIR-825AC wireless router are presented below.

  • High routing speeds
  • Support of IPv6
  • High traffic transmission speeds via PPTP
  • Support of traffic filtration powered by Yandex.DNS
  • Ability to connect user LANs using IPSec tunnels
  • Support of two wireless frequency ranges
  • Competitive price

Unfortunately, we cannot help to mention some of its drawbacks.

  • Not really high access speeds to the data located on the HDD
  • Not really high IPSec tunnel performance

As of when this article was being written, the average price for D-Link DIR-825AC wireless router in Moscow online shops was 2870 roubles.

Introduction

External design and hardware

Preparations

Firmware upgrade

Web-interface

Command line interface

Testing

Conclusion

Introduction

This time our lab hosts ASUS RT-AC51U wireless router for review, which is a classic all-in-one device that was made to meet the needs even of the most exigent user. ASUS RT-AC51U supports a wide variety of modern and popular technologies. Among them are media server, the latest generation wireless network, cloud storage server, 4G modems and MFPs, and a couple of other small features that we will be talking about in detail in the next chapters.

External design and hardware

The package box contains the comprehensive information about  what the device is really capable of. It has a USB port as well as supports cloud technologies, current modems, and high-speed wireless network. Among other things, the vendor promises the device to support IPv6 and Windows 8 (although at the moment one really should implement support of Windows 10, which has been released on July 29, 2015). The box includes the device itself, power supply unit, eight-contact patch-cord, user's manual, warranty leaflet, and a CD with the electronic version of the instruction and the utilities. Unfortunately, the PSU is not meant for vertical placement unlike the one that comes with certain other ASUS routers. Apart from this, the user's manual claims that the PSU included in the box is vertical.

The external design of the router is very typical for all devices in this series. The only difference is that the surface is completely opaque and the antennae cannot be dismounted.

A user settings reset button, ON/OFF button, power socket, USB 2.0 port, adjustable WPS/Wi-Fi OFF button, WAN port, and four LAN ports are located on the device rear panel.

On the upper panel of the device there are LEDs that indicate the correct operation of all interfaces. Side panels and the bottom panel have ventilation grates located on them. Also, there are two X-shaped mounting holes used for wall mounting of the device located on the bottom panel.

The electronic stuffing of ASUS RT-AC51U wireless router is one green textolite card which has all essential elements located on both of its sides. On the lower surface there is a Spansion FL128SAIF00 flash memory module with the size of 16 Mbytes.

The system is powered by MediaTek MT7620A SoC CPU and MediaTek MT7610EN wireless chip. Winbond W9751G6KB-25 with the overall memory size of 64 Mbytes acts as the device RAM. We already encountered the same components in, for example, ASUS RP-AC52 repeater.

Now let's pass on to reviewing of the software capabilities of the device.

Preparations

Upon the first booting of the device one can detect two wireless networks: ASUS and ASUS_5G. If the administrator decides to get connected to one of them, Windows will automatically offer him/her to adjust the device using WPS technology in a several simple steps.

 

If one decides to ignore this Windows notification upon connection to one of the networks, s/he will need to enter router.asus.com website in the browser for the initial setup of the router where s/he—following the same two-step process—can prepare the device for the first use by specifying web-interface and wireless network passwords.

Now let's pass on to reviewing of the firmware upgrade process.

Firmware upgrade

Firmware upgrade is carried out in Firmware Upgrade tab, Administration menu item. Firmware update may be carried out both in a manual and semi-automatic mode. In order to perform the latter one needs to be connected to the Internet. The whole firmware upgrade process takes about three minutes and does not require any technical proficiency from the administrator.

As of when this article was being written, there was an alternative firmware version by Padavan for ASUS RT-AC51U wireless router. The user can change to the above-mentioned firmware through the common upgrade process. However, it's worth noticing that when the upgrade process has been finished, one will need to reset all the device settings to factory defaults and adjust it manually once again.

Changing to the original firmware is done in Firmware Upgrade tab, Administration menu.

The same way, the user will need to reset the settings to factory defaults and adjust the device manually after changing to the original firmware. We have seen various complaints from users on the web that the router doesn't work after changing to the latest original firmware versions. If this is the case, one will need to boot the device upon holding WPS button, which will lead to complete reset of the user settings by the boot loader. We don't consider such behaviour of the device as problematic since the original firmware doesn't have to support configuration modes from other firmwares.

In case there was a failure during the firmware upgrade process, the firmware can be restored using Firmware Restoration utility.

Now let's pass on to reviewing the web-interface capabilities of the device.

Web-interface

Once the ASUS RT-AC51U has been rebooted, the administrator will be able to finetune it. Let's list all menu items of the web-interface: Network Map, Guest Network, Traffic Manager, Parental Controls, USB Application, AiCloud 2.0, Wireless, LAN, WAN, IPv6, VPN, Firewall, Administration, System Log, and System Tools.

As always, Network Map menu item is a user-friendly tool for access to all the frequently used network parameters and connected devices. Internet Status group shows the connection characteristics and lets one enable a capability of connection backup with the Internet through a connected 3G/4G dongle. One can specify the safety parameters and review the router utilization in the wireless network status.

Apart from all the common information, one can find out the vendor of a certain device by clicking on a MAC address in the client list. This information will be exact irrespective of the device firmware version since the request will be sent to the external MAC address database of the network equipment vendors. Also, one can assign a unique icon to every connected device and bind an address for it in a static manner.

Guest Network menu item is used to enable up to three guest networks for every frequency range (overall, there are six networks) with unique security settings, capability to adjust limitations of access to the intranet, and MAC address filter. It's nice that one can specify the lifespan of the guest network in order to not to worry about forgetting to disable it.

Traffic Manager menu item answers for management of QoS or the transferred data and monitoring of the traffic usage. QoS can be adjusted either in a manual or semi-automatic mode upon specifying the maximum speed according to a certain service plan.

Traffic monitoring features let one review the utilization on the wired and wireless networks in real time as well as review the traffic usage history during the last 24 hours or daily.

Parental controls let one set limitations on certain devices really easily (for example, on smartphones or tablets that children use) for entering the web according to a daily schedule. The access is limited completely without a possibility to create either black or white lists. On the page that contains parental controls settings there is a video that explains how to use this feature.

We believe that USB Application menu item is the most interesting one. It offers the administrator to use the USB port in six different modes. One can use all these modes at the same time upon connecting necessary devices through a USB hub. These devices may be printers, MFPs, modems, and external USB storage devices.

The device supports 3G/4G modems not just for the sake of appearance, ASUS RT-AC51U wireless router lets one use a modem as the primary or back-up channel that's automatically connected. The list of supported modems keeps on growing and the most widely-used models are supported. We had several modems like Huawei E5830 at hand, but we couldn't make them work even though they were detected successfully. It's worth noticing that these modems are not on the list of the supported models. Naturally, we notified the vendor about this and are expecting to see this modem on the list of supported devices in the next firmware versions. The latest firmware versions support operation of Android phones as a 3G/4G modem.

There are two printing protocols supported for printers: LPR and ASUS EZ. There's nothing difficult about the former, but the latter calls for some explaining. It's an easy-to-adjust software for Windows that lets one use the scanner in the MFPs, too. Contrary to what had happened with the modem support, our experience with the printer support turned out much better. And though Epson L800 we used was not on the list of supported device, however there were many other Epson L series printers, we could make the printer work after setting it up using the instructions located on the ASUS customer support website.

And, finally, support of USB sticks came to be the most elaborate. ASUS RT-AC51U wireless router can be used in order to provide public access to the user data through FTP and Samba as well as manage access to them over the web or mobile app.

Among other available features are installation of Download Master and Media Server applications. The latest versions of the software will be downloaded from the web and installed in the selected USB drive. The first application can be used to download files from HTTP and FTP resources, BitTorrent networks, eDonkey, and even Usenet. Web-interface of Download Master is located at http://192.168.1.1:8081/downloadmaster/.

Yet another advantage of Download Master is a utility for Windows that is registered in the system as the client for BitTorrent and Usenet files by default. The same utility can be used in order to install plug-ins for Chrome/IE browsers for direct download of file through Download Master without the need to enter its web-interface.

Upon usage of Download Master the user may receive an error that hides downloads from the list right after they were added. When the downloads are added once again, the user receives a notification that these tasks are already on the list. After getting connected through Samba or FTP, one will see these files in /Download/Complete folder with zero size. This error may appear after upgrading the firmware and that is why the vendor recommends the users to reinstall Download Master after every firmware upgrade.

Media Server lets common devices obtain access to media content using DLNA and iTunes standards. Web-interface of this service is available at: http://192.168.1.1:8081/mediaserverui/. It has literally no settings, doesn't divide content by categories, and makes all disks connected to the router available for use by default.

AiDisk technology offers remote access to external disks connected to the router. In order to set it up, one needs to use a special wizard that will adjust the necessary rights and open the ports. Also, if necessary, one can register a name on ASUS DDNS service and obtain an address like myrouter.asuscomm.com.

Settings of the local and remote synchronization are located in a separate menu item named AiCloud 2.0. It contains features that are meant to be used for synchronization of files between a USB stick and ASUS cloud as well as for synchronization of files between two ASUS devices with support of AiCloud 2.0 through the web. It's worth noticing that the main feature of this cloud service is about providing online access to files and folders that are not only located on the disk connected to the router, but also to files and folders located on network disks of users in the LAN. WoL (Wake on LAN) is an auxiliary feature that lets one turn the computer on remotely. It's also worth noticing that there are software clients for operation with AiCloud for devices powered by Android as well as for iPhones and iPads.

Wireless network settings are quite common for a dual frequency range device with support of 802.11AC standard.

LAN menu item is used to set only those parameters associated with the operation of IPv4. IPv6 settings are located in a separate menu item. There is also a capability of creating routes manually and receiving them from the service provider's DHCP server. And a capability to specify one or two ports for connection of IPTV Set Top Boxes.

Switch control tab includes a feature of NAT hardware acceleration that we can see more and more frequently in top router models by ASUS.

Among settings associated with the connection to the Internet there are the following types of connections: static settings, DHCP, PPPoE, L2TP, and PPTP. The most interesting thing is that the latter lets one get connected to VPN servers even with 128 bit MPPE encryption. Also, there is a helpful feature Extend the TTL value, which lets one get connected to service providers' networks that prohibit usage of routers on the client side. Technically speaking, this kind of prohibition is made possible by specifying TTL=1 field value in packets that are sent to the client. We already reviewed this technology earlier in the review of ASUS RT-N11P wireless router.

The same menu item also features port forwarding settings, DMZ, DDNS, and NAT Passthrough. And though certain ports on the external router interface are made active upon usage of AiDisk service, they cannot be seen in the port forwarding table. One can only see a notification about a possible conflict of ports upon using them manually. Manual forwarding will be given priority in this case.

As we already said earlier, all IPv6 settings are located in the separate same-named menu item. The following connection types are supported: static and dynamic addresses (Stateful and Stateless) as well as 6to4, 6in4, and 6rd tunnels.

Availability of the built-in VPN server that functions using PPTP with MSCHAPv2 authorization, and MPPE encryption with the key length of up to 128 bits came to be a nice capability. Also, one can use a well-protected OpenVPN server with a lot of security settings for clients.

Apart from the VPN server feature, there is also a VPN client capability. It may come in handy if one needs to get connected to a corporate network remotely. The following protocols are supported: OpenVPN, PPTP, and L2TP.

Firewall settings feature both the classic security means—protection against DoS attacks, denying sending echo-replies through ICMP, filtration of websites according to the URL addresses—and more elaborate technologies like filtration of web pages according to the key words (apart from compressed pages and HTTPS) and port filtering.

The same menu item is used to manage IPv6 traffic filtering. All outgoing and reply IPv6 traffic is permitted, but one will need to permit the incoming traffic separately.

Administration menu item lets the administrator choose the device operation mode: wireless router or access point; specify the administrator's password, manage time synchronization, enable or disable access through telnet.

The same menu item is used for checking the firmware updates, backing up settings, or resetting the user settings.

System Log is divided into several categories: general output of messages of all active services, wireless network, DHCP, IPv6, routing table, port forwarding table, and NAT translations table.

Among network utilities are the following: ping, traceroute, nslookup, netstat as well as Wake-On-Lan feature that lets one save devices' MAC addresses, which may come in handy since the administrator won't need to type in MAC addresses by hand.

That is where we bring review of the router web-interface to a conclusion and pass on to examining the capabilities of its command line.

Command line interface

Managing the access to the command line is performed using System tab, Administration menu item in the web-interface.

Firmware of the model under review is built on Linux 2.6.36 OS using Busy Box 1.17.4.

RT-AC51U login: admin
Password:
ASUSWRT RT-AC51U_3.0.0.4 Sat Jan 10 18:55:04 UTC 2015
admin@RT-AC51U:/tmp/home/root# cd /
admin@RT-AC51U:/# busybox
BusyBox v1.17.4 (2015-01-11 02:55:02 CST) multi-call binary.
Copyright (C) 1998-2009 Erik Andersen, Rob Landley, Denys Vlasenko
and others. Licensed under GPLv2.
See source distribution for full notice.
Usage: busybox [function] [arguments]...
 or: function [arguments]...
 BusyBox is a multi-call binary that combines many common Unix
 utilities into a single executable.  Most people will create a
 link to busybox for each function they wish to use and BusyBox
 will act like whatever it was invoked as.
Currently defined functions:
 [, [[, arp, ash, awk, basename, blkid, cat, chmod, chown, chpasswd, clear, cmp, cp, crond,
 cut, date, dd, df, dirname, dmesg, du, e2fsck, echo, egrep, env, ether-wake, expr, fdisk,
 fgrep, find, flock, free, fsck.ext2, fsck.ext3, fsck.minix, fsync, grep, gunzip, gzip,
 head, ifconfig, insmod, ionice, kill, killall, klogd, less, ln, logger, login, ls, lsmod,
 lsusb, md5sum, mdev, mkdir, mke2fs, mkfs.ext2, mkfs.ext3, mknod, mkswap, modprobe, more,
 mount, mv, netstat, nice, nohup, nslookup, pidof, ping, ping6, printf, ps, pwd, readlink,
 renice, rm, rmdir, rmmod, route, sed, setconsole, sh, sleep, sort, strings, swapoff,
 swapon, sync, syslogd, tail, tar, telnetd, test, top, touch, tr, traceroute, traceroute6,
 true, tune2fs, udhcpc, umount, uname, unzip, uptime, usleep, vconfig, vi, watch, wc, wget,
 which, zcat, zcip
admin@RT-AC51U:/# uname -a
Linux RT-AC51U 2.6.36 #1 Sun Jan 11 02:58:33 CST 2015 mips GNU/Linux
admin@RT-AC51U:/#

Let's see what processes are currently running using ps command. By using top utility one can obtain information on the current activity of the launched processes.

admin@RT-AC51U:/# ps
 PID USER       VSZ STAT COMMAND
 1 admin     4076 S    /sbin/init
 2 admin        0 SW   [kthreadd]
 3 admin        0 SW   [ksoftirqd/0]
 4 admin        0 SW   [kworker/0:0]
 5 admin        0 SW   [kworker/u:0]
 6 admin        0 SW<  [khelper]
 7 admin        0 SW   [sync_supers]
 8 admin        0 SW   [bdi-default]
 9 admin        0 SW<  [kintegrityd]
 10 admin        0 SW<  [kblockd]
 11 admin        0 SW   [kswapd0]
 12 admin        0 SW   [fsnotify_mark]
 13 admin        0 SW<  [crypto]
 17 admin        0 SW   [mtdblock0]
 18 admin        0 SW   [mtdblock1]
 19 admin        0 SW   [mtdblock2]
 20 admin        0 SW   [mtdblock3]
 21 admin        0 SW   [mtdblock4]
 22 admin        0 SW   [mtdblock5]
 23 admin        0 SW   [mtdblock6]
 24 admin        0 SW   [kworker/u:1]
 31 admin        0 SW   [kworker/0:1]
 42 admin      660 S    hotplug2 --persistent --no-coldplug
 89 admin     4060 S    console
 90 admin     1596 S    /bin/sh
 97 admin        0 SW   [khubd]
 177 admin     4068 S    usbled
 270 admin     4068 S    wpsaide
 304 admin     1592 S    crond
 305 admin     1092 S    /usr/sbin/infosvr br0
 308 admin     4068 S    watchdog
 310 admin     1300 S    rstats
 324 admin     1184 S    lld2d br0
 326 admin     4068 S    ots
 328 admin      748 S    miniupnpd -f /etc/upnp/config
 344 admin     1188 S    lpd
 528 admin     4068 S    ntp
 609 admin     1580 S    syslogd -m 0 -S -O /tmp/syslog.log -s 256 -l 6
 611 admin     1580 S    /sbin/klogd
 620 admin     1584 S    telnetd
 731 admin        0 SW   [RtmpCmdQTask]
 732 admin        0 SW   [RtmpWscTask]
 749 admin        0 SW   [RtmpCmdQTask]
 750 admin        0 SW   [RtmpWscTask]
 768 admin     4068 S    /sbin/wanduck
 771 nobody     988 S    dnsmasq --log-async
 774 admin     1588 S    udhcpc -i vlan2 -p /var/run/udhcpc0.pid -s /tmp/udhcpc -O33 -O249
 826 admin     3988 S    httpd
 827 admin     1196 S    networkmap
 829 admin     2108 S    u2ec
 831 admin     2108 S    u2ec
 833 admin     2108 S    u2ec
 844 admin     3260 S <  /usr/sbin/smbd -D -s /etc/smb.conf
 845 admin     2392 S    nmbd -D -s /etc/smb.conf
 848 admin     1604 S    -sh
 864 admin     1584 R    ps
admin@RT-AC51U:/#top
Mem: 46376K used, 15128K free, 0K shrd, 5188K buff, 15792K cached
CPU:   0% usr   0% sys   0% nic  98% idle   0% io   0% irq   1% sirq
Load average: 0.00 0.06 0.04 1/56 866
 PID  PPID USER     STAT   VSZ %MEM %CPU COMMAND
 865   848 admin    R     1592   3%   1% top
 1     0 admin    S     4076   7%   0% /sbin/init
 308     1 admin    S     4068   7%   0% watchdog
 270     1 admin    S     4068   7%   0% wpsaide
 326   308 admin    S     4068   7%   0% ots
 768     1 admin    S     4068   7%   0% /sbin/wanduck
 528     1 admin    S     4068   7%   0% ntp
 177     1 admin    S     4068   7%   0% usbled
 89     1 admin    S     4060   7%   0% console
 826     1 admin    S     3988   6%   0% httpd
 844     1 admin    S <   3260   5%   0% /usr/sbin/smbd -D -s /etc/smb.conf
 845     1 admin    S     2392   4%   0% nmbd -D -s /etc/smb.conf
 833   831 admin    S     2108   3%   0% u2ec
 829     1 admin    S     2108   3%   0% u2ec
 831   829 admin    S     2108   3%   0% u2ec
 848   620 admin    S     1604   3%   0% -sh
 90    89 admin    S     1596   3%   0% /bin/sh
 304     1 admin    S     1592   3%   0% crond
 774     1 admin    S     1588   3%   0% udhcpc -i vlan2 -p /var/run/udhcpc0.pid -s /tmp/udhcpc -O
 620     1 admin    S     1584   3%   0% telnetd
 611     1 admin    S     1580   3%   0% /sbin/klogd
 609     1 admin    S     1580   3%   0% syslogd -m 0 -S -O /tmp/syslog.log -s 256 -l 6
 310     1 admin    S     1300   2%   0% rstats
 827     1 admin    S     1196   2%   0% networkmap
 344     1 admin    S     1188   2%   0% lpd
 324     1 admin    S     1184   2%   0% lld2d br0
 305     1 admin    S     1092   2%   0% /usr/sbin/infosvr br0
 771     1 nobody   S      988   2%   0% dnsmasq --log-async
 328     1 admin    S      748   1%   0% miniupnpd -f /etc/upnp/config
 42     1 admin    S      660   1%   0% hotplug2 --persistent --no-coldplug
 21     2 admin    SW       0   0%   0% [mtdblock4]
 3     2 admin    SW       0   0%   0% [ksoftirqd/0]
 4     2 admin    SW       0   0%   0% [kworker/0:0]
 20     2 admin    SW       0   0%   0% [mtdblock3]
 31     2 admin    SW       0   0%   0% [kworker/0:1]
 2     0 admin    SW       0   0%   0% [kthreadd]
 23     2 admin    SW       0   0%   0% [mtdblock6]
 24     2 admin    SW       0   0%   0% [kworker/u:1]
 97     2 admin    SW       0   0%   0% [khubd]
 22     2 admin    SW       0   0%   0% [mtdblock5]
 731     2 admin    SW       0   0%   0% [RtmpCmdQTask]

Contents of /bin, /sbin, /usr/bin, and /usr/sbin catalogs, as well as the output of sysinfo utility, are located in a separate file.

Now let's turn to /proc catalogue to view its contents and find out the system uptime, its average utilisation, information on the CPU installed, and the amount of RAM. Actually, system uptime and average system utilisation can also be learnt using uptime command.

admin@RT-AC51U:/# cd /proc
admin@RT-AC51U:/proc# ls
1              305            732            960            kcore          softirqs
10             308            749            97             kmsg           stat
11             31             750            buddyinfo      kpagecount     swaps
12             310            768            bus            kpageflags     sys
13             324            771            cmdline        loadavg        sysrq-trigger
17             326            774            cpuinfo        locks          sysvipc
177            328            8              crypto         meminfo        timer_list
18             344            826            devices        misc           tty
19             4              827            diskstats      modules        uptime
2              42             829            driver         mounts         version
20             5              831            execdomains    mt7620         vmallocinfo
21             528            833            filesystems    mtd            vmstat
22             6              844            fs             net            zoneinfo
23             609            845            interrupts     nvram
24             611            848            iomem          pagetypeinfo
270            620            89             ioports        partitions
3              7              9              irq            scsi
304            731            90             kallsyms       self
admin@RT-AC51U:/proc# cat uptime
1190.00 1130.26
admin@RT-AC51U:/proc# cat loadavg
0.01 0.02 0.01 1/56 962
admin@RT-AC51U:/proc# cat cpuinfo
system type             : Ralink SoC
processor               : 0
cpu model               : MIPS 24Kc V5.0
BogoMIPS                : 386.04
wait instruction        : yes
microsecond timers      : yes
tlb_entries             : 32
extra interrupt vector  : yes
hardware watchpoint     : yes, count: 4, address/irw mask: [0x0ffc, 0x0ffc, 0x0ffb, 0x0ffb]
ASEs implemented        : mips16 dsp
shadow register sets    : 1
core                    : 0
VCED exceptions         : not available
VCEI exceptions         : not available
admin@RT-AC51U:/proc# cat meminfo
MemTotal:          61504 kB
MemFree:           14972 kB
Buffers:            5220 kB
Cached:            15844 kB
SwapCached:            0 kB
Active:            16632 kB
Inactive:           9368 kB
Active(anon):       5124 kB
Inactive(anon):      224 kB
Active(file):      11508 kB
Inactive(file):     9144 kB
Unevictable:           0 kB
Mlocked:               0 kB
SwapTotal:             0 kB
SwapFree:              0 kB
Dirty:                 0 kB
Writeback:             0 kB
AnonPages:          4940 kB
Mapped:             3472 kB
Shmem:               412 kB
Slab:              12112 kB
SReclaimable:       2188 kB
SUnreclaim:         9924 kB
KernelStack:         448 kB
PageTables:          404 kB
NFS_Unstable:          0 kB
Bounce:                0 kB
WritebackTmp:          0 kB
CommitLimit:       30752 kB
Committed_AS:      11644 kB
VmallocTotal:    1048372 kB
VmallocUsed:        7892 kB
VmallocChunk:    1008456 kB
admin@RT-AC51U:/proc# uptime
 03:20:10 up 20 min, load average: 0.00, 0.02, 0.00
admin@RT-AC51U:/proc#

We can't help but mention nvram utility that allows changing certain important device operation parameters.

admin@RT-AC51U:/proc# nvram
usage: nvram [get name] [set name=value] [unset name] [show] [save file] [restore file]
admin@RT-AC51U:/proc# nvram show | grep admin
http_username=admin
http_passwd=admin
size: 31379 bytes (30061 left)
acc_list=admin>admin
acc_webdavproxy=admin>1

That's where we proceed to completion of the brief review of the command line interface capabilities and pass directly on to testing the device.

Testing

The first testing procedure we always begin our testing section with is estimating the booting time of the device, which is a time interval starting with the moment when the power is on until the first echo reply is received through ICMP protocol. ASUS RT-AC51U wireless router boots in 41 seconds. We believe that the result is decent.

The second traditional test was a security scanning procedure, which has been carried out using Positive Technologies XSpider 7.7 (Demo build 3100) utility. On the whole, there were 15 open ports discovered. The most interesting data are presented below.

Before getting straight down to performance tests we would like to mention the key specifications of the test stand we used.

Component PC Notebook
Motherboard ASUS Maximus VI Extreme ASUS M60J
CPU Intel Core i7 4790K 4 GHz Intel Core i7 720QM 1.6 GHz
RAM DDR3 PC3-10700 SEC 32 Gbytes DDR3 PC3-10700 SEC 16 Gbytes
NIC Intel PRO/1000 PT
ASUS PCE-AC68
Atheros AR8131
ASUS RT-AC66U
OS Windows 7 x64 SP1 Rus Windows 7 x64 SP1 Rus

 

NAT/PAT feature in RT-AC51U router can be disabled and that's why we measured the device performance both upon performing ordinary routing and routing with NAT/PAT. In case of the latter the measurements were carried out in two modes: with enabled and disabled hardware acceleration. In order to test it we used JPERF utility, 2.0.2 version. The tests were carried out with 1, 5, and 15 concurrent TCP connections.

At first glance, usage of hardware acceleration doesn't help increase the routing speed. However, enabling hardware acceleration decreases the load on the CPU and makes it available for performing other tasks.

We couldn't keep away from support of PPTP/L2TP/PPPoE tunnels by the router. Usually, the PPTP performance is the lowest and that's why we decided to perform the measurements using this connection type. Results of the measurements are presented on the diagram below. The measurements were made both using MPPE128 encryption and without it.

Apart from the support of the current version of IP protocol, IPv4, ASUS RT-AC51U wireless router also supports operation with the next generation protocol, IPv6.

Presence of a USB port lets the administrator get external drives connected to the device under review: flash cards and HDDs with a USB interface. Access speeds to the user data stored on such an external device are presented on the diagram below. In order to make the measurements we used our standard 750 Gbytes Transcend StoreJet 25M3 hard disk, which we successively formatted into the following file systems: FAT32, NTFS, and EXT2/3.

It's obvious that in this case Fast Ethernet interface is a bottleneck.

Also, we decided to measure the performance of Download Master application that is being executed in the router. We decided to use a popular torrent upload that had an approximate size of 2 GBytes for our measurements. At first we downloaded this file using a torrent client installed on a PC connected to RT-AC51U LAN port. The measured speed was about 11 Mbyte/s, which corresponds to the performance of Fast Ethernet. Then we connected an external hard disk to the router and started downloading the file to it. The speeds that we received depended mainly on the file system used. This way, the average download speed for NTFS partition was 1.3 Mbyte/s. EXT3 partition demonstrated the average speed of 2.1 Mbyte/s. Graphs located below show the utilization of the router external interface upon operation with Download Master for both of the file systems. It's worth noticing that ASUS RT-AC51U CPU utilization during the test was 100% all the time and that makes us believe that the received speeds are limited by the performance of the router itself.

Finally, we are about to test the performance of the wireless module of the router. At first we carried out the measurements for one pair of client devices: one wired and one wireless client. Once again, it looked like the received speeds were limited by Fast Ethernet interface too. That's why we decided to add the second pair of client devices and load the wireless network segment to the max. Results of the measurements for both frequency ranges are presented on the diagram below.

During our performance tests, the router case temperature didn't get higher than 33°С. The environment temperature was 25°С.

That's where we draw the testing chapter to a close and move on to summing it all up.

Conclusion

Generally, we are quite glad about ASUS RT-AC51U wireless router, which is the successor of RT-AC52U model. The device is fitted with 100 Mbps Fast Ethernet ports and two wireless adapters that provide theoretically possible speeds of up to 300 Mbps in 2.4 GHz frequency range and 433 Mbps in 5 GHz frequency range. We believe that the router under review is well balanced when it comes to the interfaces' speed. Obviously, RT-AC51U won’t become a favourite of geeks, but it will definitely meet all needs of a common user.

Among the strength areas of ASUS RT-AC51U wireless router are the following.

  • High performance of VPN
  • A built-in VPN client and server
  • Support of 802.11AC wireless network
  • A lot of new interesting features
  • Support of IPv6
  • Availability of alternative firmware
  • Competitive price

Unfortunately, we cannot help but mention certain drawbacks of the model.

  • The web-interface is not completely translated
  • Certain insignificant errors in the firmware
  • No Gigabit Ethernet ports

As of when this article was being written, the average price for ASUS RT-AC51U in Moscow online shops was 4600 roubles.