Mobile wireless router for 3G/Wi-Fi networks or ASUS WL-330N3G

Introduction

External design and hardware

Firmware upgrade

Web-interface review

Additional utilities and command line interface

Testing

Conclusion

Introduction

From time to time the ASUS Company produces tiny wireless network hybrids mainly targeted at users who travel a lot. One of these devices is an access point WL-330gE intended for working with 802.11g networks, also there’re WL-330N and WL-330N3G models with 802.11n support. Today in our testing lab we have a multifunctional 802.11n standard access point with 3G modems support - ASUS WL-3330N3G. Let’s see what a device with the size of a credit card is capable of.

External design and hardware

The ASUS WL-3330N3G model is really a miniature, its dimensions are only 90*39*13 mm.

The upper panel is slightly convex where the Fast Ethernet interface is placed in the side. Also here there’re four light indicators depicting the status of power supply, wired, Wi-Fi and 3G network segments; ventilation holes, the vendor’s name and the device model, and a WPS button for simplified wireless network configuration. We have to mention that we had a test copy of the device, so the marking on it (AP-N13M) isn’t the same as an end user will see. On the bottom panel there’re ventilation holes, a recessed Restore button for setting all user configurations to default and a sticker with brief information about the device.

One of the side panels displays an RJ-45 port and a USB port. The only thing to say here is that this USB port is only for the access point power supply; connection to the PC for data transmission is not included. The device can also be powered with a special AC adapter.

Another side also has a USB port that can be used, if necessary, for connecting external 3G USB modems.

Inside WL-330N3G consists of one textolite board whose main elements are hidden under a metal screen.

Now let’s have a look at the device software.

Firmware upgrade

The firmware version can be upgraded from the Firmware upgrade menu of the Administration group. The process itself is not complicated at all – you only have to choose the file with new firmware and click on Upload.

The whole process takes about three minutes and doesn’t demand any particular skills from the user.

If some malfunction occurs while firmware is being updated, WL-330N3G enters a failure mode. In this case you’ll have to resort to the firmware recovery procedure with the help of the Firmware Restoration utility. The process is extremely simple: just choose the file with firmware and click on Upload; the utility will detect the malfunctioning device by itself and will restore the firmware and reboot the device.

We deliberately unplugged the router during standard firmware upgrade to test the Firmware Restoration utility. The actions described above turned WL-330N3G in some mode when it didn’t function correctly and wasn’t detected by the given utility, either. Meanwhile, the light indicator of power supply was glowing, whereas if a router is being recovered it should flash. Then we rebooted the device pressing the Restore button. Such rebooting drove ASUS WL-330N3G into the firmware rescue mode after which we readily recovered the device with the help of the Firmware Restoration utility.

WL-330N3G can be restored without any special utilities. For this you have to transmit the firmware file to the device via TFTP. Then WL-330N3G will save the obtained image in its flash-memory and reboot.

C:\>tftp -i 192.168.1.1 put WL-330N3G_1.0.2.0.trx
Successful transfer: 3810422 bytes in 4 sec., 952605 bytes/s

Here we’re through with the section devoted to changing firmware versions and move on to discussing the web-interface features.

Web-interface review

WL-330N3G initial configuration is performed with the help of a wired connection for which 192.168.1.1 IP-address is used. By default the login and password are admin/admin.

After entering correct account data the user gets to the device home page available in eleven languages where he can choose one of WL-330N3G six working modes. Let’s consider each of them in more detail.

In the Wireless Router mode the user can connect to the wired network using a static or dynamic IP-address and to enable VPN (PPPoE, PPTP or L2TP). All client devices are connected via a wireless network whose name and authentication method can be set on the respective page. Such connection method can be necessary for those home users who have only wireless devices.

The difference of the Access Point mode from the previous one is that the wired and wireless networks are connected by a switch, meaning there’s no IP sharing and routing. In the Access Point mode ASUS WL-330N3G can be used in the case when there’s a need to create a wireless segment in a pre-existing wired network.

If one wants to extend the existing wireless network, it’s possible to use the Repeater mode. In this case you’ll have to choose the name of the network whose signal has to be repeated.

If one wants to connect a notebook, a PC or any other device lacking a wireless NIC to the wireless network, there’s a Wireless Network Adapter mode. In this case WL-330N3G itself connects to the wireless network and transmits data between the wired and wireless segments. The equipment thus connected has only to be able to connect to Fast Ethernet with a patch-cord.

The Hotspot mode may come in handy when it’s necessary to connect several wireless devices to an existing pay wireless net. ASUS WL-330N3G is to be connected to the network and all user devices are “hidden” behind the router.

The 3G Sharing mode is similar to the previous one; the only difference is that in this mode, connection to wireless 3G networks is performed with the help of an additional modem attached to the USB port.

Now let’s turn our attention to the Advanced Settings menu and look at some additional features available to the user in the web-interface.

The General tab of the Wireless group allows setting main parameters of the Wi-Fi module operation. Besides standard features there’s an option of adjusting the power of the wireless transmitter.

The points of the LAN group are for specifying the device LAN-interface address, managing the DHCP-server and the routing table. A nice feature here is the possibility of dynamically getting the routing table from the provider via DHCP.

General settings for connecting to the provider as well as virtual servers and DDNS parameters can be found in the points of the WAN group.

The parameters of filtering based on MAC-addresses, URL, UDP/TCP ports and IP-addresses are presented in the points of the Firewall group.

With the help of the menu items of the Administration group the user can change the password for accessing the device, specify the time zone, upgrade firmware and reset/recover/backup user settings. Unfortunately, the list of time zones doesn’t take into account the latest changes in Russian regulations regarding the use of daylight saving time which has been discontinued. So Moscow is still put in the GMT+03.00 time zone as before.

The System Log group provides log information, displays the routing table, information about the DHCP server operation and some other data. It’s worth drawing the readers’ attention to the fact that the routing table can contain not only those static routes written manually but also routes received from the provider via DHCP.

Here we would like to finish the review of ASUS WL-330N3G web-interface, and it’s time to describe alternative means of managing the device.

Additional utilities and command line interface

The utility package is installed in the same way as all other software packages for ASUS wireless devices.

During installation the antivirus program protecting our test PC displayed a message about hidden installation of a driver required for detecting ASUS devices in the local net. For software correct operation this installation should be allowed.

In the package there’re four utilities: Device Discovery, Firmware Restoration, Router Setup Wizard and WPS Wizard. With the help of Device Discovery the user can discover WL-330N3G or any other correctly operating ASUS wireless device.

The abilities of Firmware Restoration were described above in the section devoted to firmware upgrade, so let’s briefly describe the two remaining programs. The Router Setup Wizard and WPS Wizard utilities detect a wireless router in the local segment, offer the user to connect a 3G-modem to it and open the device web-interface for further configuration; they also simplify wireless network configuration.

Besides the actions described above the utilities at hand connect to the vendor’s site for downloading updated firmware versions.

Another way of managing WL-330N3G is the command line of the built-in operating system. It can be accessed in the way standard for all ASUS wireless production – with the help of a hidden administration page Main_AdmStatus_Content.asp. However, there’re some minor differences – you have to run the run_telnetd command instead of starting the telnetd daemon.

The account data for accessing the command line are the same as in the device web-interface. Inside WL-330N3G we saw the BusyBox library version 1.12.1 traditional for such devices. The Linux kernel version is 2.6.21.

WL-330N3G login: admin
Password:
BusyBox v1.12.1 (2011-08-31 14:54:53 CST) built-in shell (ash)
Enter 'help' for a list of built-in commands.
# busybox
BusyBox v1.12.1 (2011-08-31 14:54:53 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:
 [, [[, ash, basename, brctl, cat, chmod, chpasswd, cp, date, echo, expr, free, 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, vconfig, vi, wc
# cat /proc/version
Linux version 2.6.21 (This email address is being protected from spambots. You need JavaScript enabled to view it.n) (gcc version 3.4.2) #9 Thu Nov 10 16:34:08 CST 2011
With the help of the ps command let’s see what processes are running on the device at the moment.
# ps
 PID USER       VSZ STAT COMMAND
 1 admin     2652 S    /init
 2 admin        0 SWN  [ksoftirqd/0]
 3 admin        0 SW<  [events/0]
 4 admin        0 SW<  [khelper]
 5 admin        0 SW<  [kthread]
 32 admin        0 SW<  [kblockd/0]
 35 admin        0 SW<  [khubd]
 47 admin        0 SW<  [kswapd0]
 48 admin        0 SW   [pdflush]
 49 admin        0 SW   [pdflush]
 50 admin        0 SW<  [aio/0]
 194 admin        0 SW   [mtdblockd]
 262 admin        0 SW   [RtmpWscTask]
 284 admin     1088 S    dproxy -c /tmp/dproxy.conf
 286 admin     3060 S    httpd ppp0
 290 admin     1464 S    /usr/sbin/udhcpd /tmp/udhcpd.conf
 291 admin     1464 S    /usr/sbin/infosvr br0
 292 admin     1700 S    /sbin/syslogd -m 0 -t GMT0 -O /tmp/syslog.log
 294 admin     1700 S    /sbin/klogd
 310 admin     2984 S    upnpd -f eth2.2 br0
 312 admin     2984 S    upnpd -f eth2.2 br0
 314 admin     2984 S    upnpd -f eth2.2 br0
 316 admin     2984 S    upnpd -f eth2.2 br0
 318 admin     2984 S    upnpd -f eth2.2 br0
 320 admin     2984 S    upnpd -f eth2.2 br0
 321 admin     2984 S    upnpd -f eth2.2 br0
 323 admin     1196 S    lld2d br0
 324 admin     2984 S    upnpd -f eth2.2 br0
 325 admin     2984 S    upnpd -f eth2.2 br0
 327 admin     1464 S    /usr/sbin/wanduck
 330 admin     2648 S    watchdog
 341 admin        0 SW<  [dwc_otg]
 347 admin     2648 S    ntp
 350 admin     2648 S    ots
 357 admin     1472 S    networkmap
 358 admin     1708 S    /bin/sh
 364 admin     2984 S    upnpd -f eth2.2 br0
 389 admin     1704 S    telnetd
 390 admin     1716 S    -sh
 393 admin     1704 R    ps

We placed the list of files in the /bin, /sbin, /usr/bin and /usr/sbin folders into a separate file.

Now let’s see what files are located in the /proc catalogue and find out the operating system uptime and its average load; get information about the CPU and the amount of RAM.

# pwd
/proc
# cat uptime
1982.09 1967.88
# cat loadavg
0.00 0.00 0.00 1/40 400
# cat cpuinfo
system type             : Ralink SoC
processor               : 0
cpu model               : MIPS 24K V4.12
BogoMIPS                : 212.99
wait instruction        : yes
microsecond timers      : yes
tlb_entries             : 32
extra interrupt vector  : yes
hardware watchpoint     : yes
ASEs implemented        : mips16 dsp
VCED exceptions         : not available
VCEI exceptions         : not available
# cat meminfo
MemTotal:        28944 kB
MemFree:          8524 kB
Buffers:             0 kB
Cached:          11912 kB
SwapCached:          0 kB
Active:           6192 kB
Inactive:         7368 kB
SwapTotal:           0 kB
SwapFree:            0 kB
Dirty:               0 kB
Writeback:           0 kB
AnonPages:        1688 kB
Mapped:           1524 kB
Slab:             4284 kB
SReclaimable:      864 kB
SUnreclaim:       3420 kB
PageTables:        304 kB
NFS_Unstable:        0 kB
Bounce:              0 kB
CommitLimit:     14472 kB
Committed_AS:     3964 kB
VmallocTotal:  1048404 kB
VmallocUsed:      1660 kB
VmallocChunk:  1046160 kB

In the /proc/filesystems and /proc/crypto files one can find the list of supported file systems and types of encryption.

# cat /proc/filesystems
nodev   sysfs
nodev   rootfs
nodev   bdev
nodev   proc
nodev   sockfs
nodev   usbfs
nodev   pipefs
nodev   futexfs
nodev   tmpfs
nodev   eventpollfs
nodev   devpts
 ext2
 squashfs
nodev   ramfs
 vfat
nodev   fuse
 fuseblk
nodev   fusectl
# cat /proc/crypto
name         : ecb(arc4)
driver       : ecb(arc4-generic)
module       : kernel
priority     : 0
refcnt       : 1
type         : blkcipher
blocksize    : 1
min keysize  : 1
max keysize  : 256
ivsize       : 0
name         : arc4
driver       : arc4-generic
module       : kernel
priority     : 0
refcnt       : 1
type         : cipher
blocksize    : 1
min keysize  : 1
max keysize  : 256
name         : sha1
driver       : sha1-generic
module       : kernel
priority     : 0
refcnt       : 1
type         : digest
blocksize    : 64
digestsize   : 20

Naturally, we couldn’t overlook the nvram utility traditional for ASUS devices – the one that helps the user to inspect and change the system main settings.

# nvram show | grep 192.168.1
size: 11576 bytes (21192 left)
lan_ipaddr_t=192.168.1.1
dhcp_start=192.168.1.2
dhcp_end=192.168.1.254
lan_gateway_t=192.168.1.1
lan_ipaddr=192.168.1.1

Now let’s test the device.

Testing

Traditionally, the first test is determining the device booting time under which we mean the time interval between switching power on to the first echo-reply via ICMP. ASUS WL-330N3G boots in 35 seconds, which think to be a normal result.

The second test was checking the device security with the help of the Positive Technologies XSpider 7.7 (Demo build 3100) network security scanner. Altogether we detected five open ports: UDP-53 (DNS), TCP-80 (HTTP), TCP-9998, TCP-18017 (HTTP) and TCP-49152 (HTTP). The most interesting data we obtained are presented below.

We don’t consider the discovered insecurities critical, except for a possible DoS-attack against the DNS service that we reported to the vendor.

Also we couldn’t turn our back to the possibility of connecting to 3G networks for which we used a ZTE MF100 modem intended for working in the networks of one of Russian mobile operators. The connection was readily established but was broken within five minutes. We repeated the process and again after five minutes the connection was lost. According to the vendor, such unstable performance is typical for only a small number of modems and all other devices work correctly. The list of modems tested by the vendor is available on the ASUS website.

The next test was to use WL-330N3G as a wireless adaptor for an Avaya 9650 IP-telephone. To power the phone itself we used a PoE-adaptor and planned to power WL-330N3G from the USB port of the phone. However, it turned out that for the USB port to turn on, the telephone had to detect an Ethernet connection. That is, we had a vicious circle: without USB power the router wouldn’t switch on and without a router the telephone wouldn’t supply power to the USB port in the side panel. Then we took a Nokia E52 charger with micro-USB interface to power WL-330N3G. The router readily connected to the existing wireless network, which allowed us to use the wired Avaya 9650 IP-telephone in any place within the coverage of our test access point. We certainly understand the complete lack of sense in the realized construction; however as a result of this experiment we discovered that our subscribers didn’t notice any difference in the quality of connection – was it a wired or a wireless connection of the telephone.

Undoubtedly, for our readers the most eagerly awaited test is measuring data transmission speeds in WL-330N3G different modes of operation. We didn’t measure the device speed in 3G networks because we think that the results of such measurements can differ significantly depending on the mobile operator, the device location, time of day and other factors. So the first thing we did was to measure the data transmission speed when WL-330N3G worked as an access point. Theoretically, the maximum transmission speed is 150 Mbps. The obtained results are presented on the diagram below. The measurements were held for one, five and fifteen simultaneous connections.

Then we measured data transmission speeds when WL-330N3G was in the router mode with NAT, then we repeated the experiment with a PPTP connection to the provider. The measurements results are presented below.

We consider the obtained rates to be quite acceptable for such devices; a year or two ago even full-sized SOHO-routers couldn’t boast such access rates via PPTP.

Here we finish our testing section; let’s see what we finally have.

Conclusion

ASUS WL-330N3G – a miniature wireless router – made a very pleasant impression. We were happy with its functionality and data transmission speeds. Its tiny size and mass make the device extremely convenient for travellers; in some countries the set includes an automobile power adapter – this fact allows connecting several wireless Wi-Fi devices inside the vehicle to a 3G network.

The advantages of WL-330N3G are listed below.

  • Small size
  • Several modes of operation
  • Support of 3G networks
  • Acceptable data transmission rates via PPTP tunnels
  • Ability of powering the device from a notebook or PC USB port

Unfortunately, we have to mention some disadvantages, too.

  • Very long rebooting time
  • Unstable operation with some outdated 3G-modems

When the article was being written the average price for ASUS WL-330N3G in Moscow online shops was 1850 RUR.

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