ADSL2+ Switch with Annex L and Annex M Support or D-Link DAS-3248EC

Introduction

External design

Hardware

Firmware upgrade

Web-interface

Command line

SNMP-access

Testing

Conclusion

Introduction

Residents of big cities consider the dial-up network access technology as something irreparably beyond retrieve and dimly remember it only as a nightmare. However, those who live in rural areas, especially in countries like Russia, have no choice but to use the ADSL technology since the dial-up access does not provide acceptable speeds, while laying out a fibre optic cable is a completely impracticable solution. Today our laboratory hosts D-Link DAS-3248EC DSLAM with support of Annex L and Annex M, which takes rural population a huge step closer to those people who live in hectic cities.

External design

D-Link DAS-3248EC ADSL switch comes in a black metal case that is used for rack mounting. The device has dimensions of 438x320x50 mm not including the brackets, which are used to mount the device both in 19-inch and 23-inch racks.

Side panels have ventilation grates located on them. One of the side panels has four 40x40 mm fans located on it in order to enhance the cooling.

On the rear panel there is a power supply socket.

While upper and bottom panels are not remarkable at all. It's worth noticing that on the bottom side of the device there is a sticker with brief information about the device and four seats for rubber legs which allow mounting DAS-3248EC on a table.

On the front panel there are four Telco-50 sockets; two of them are used for connection to PBX switching equipment, while the other two serve for connection of common users. Apart from it, there are LEDs indicating the device and user port statuses located on it. A contact block is used for alarm signal IO. Grounding connection, which is also located on the front panel, is carried out using a screw. To connect the administrator one should use either Console or Management port. Two integrated ports SFP/RJ45 are used to connect DAS-3248EC to the aggregation level of the service provider network.

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

Hardware

Hardware platform of DSLAM D-Link DAS-3248EC consists of three textolite cards: main board, card with filters and card with a power supply unit.

Let's examine components located on both sides of the main board in more detail. On the inner side there is a Lattice LC4256V FPLD and four ISSI IS61LV5128AL CMOS modules, 512 Kbytes each. RAM of the device are four Micron 48LC16M16A2 chips with the size of 32 Mbytes each, making the total RAM size of the device 128 Mbytes.

On the front side there are three IC Plus IP1000A chips that act as the NIC; two Broadcom BCM5461S modules are used as transceivers. Also, there are six Ikanos GS3800-808-011AAZ and three Ikanos GS7966-424-112BBZ chips located here.

Now let's skip on to reviewing the software platform of the device.

Firmware upgrade

Firmware upgrade is carried out using Firmware upgrade tab, System group, in the web-interface menu. One only needs to browse a file with the new firmware version and click on Upgrade button.

The whole firmware upgrade process takes about four minutes and does not require any technical proficiency from an administrator.

Web-interface

One can access the web-interface of the ADSL D-Link DAS-3248EC switch using any modern browser. In order to connect to the device an administrator must specify login and password, which are Admin/Admin by default.

Upon the successful authentication an administrator will find him/herself on the home page of the DSLAM.

Let's have a closer look at the features available in several groups of the device web-interface menu. System group allows an administrator to receive information about the system, upgrade the current firmware version, manage user settings and log-on information, and reboot the device.

Information on working parameters of DSL, upstream and downstream, statistics on virtual channels and Ethernet ports, status of GBIC modules (which are actually SFP modules), and data from the transducers are located in subgroups of Status & Performance group.

On/off switching of ports is carried out using DSL port enable subgroup, Deployment & Configuration group.

Management of ADSL profiles and port binding is carried out using DSL profile and DSL profile mapping subgroups, the same-named group.

Management of virtual paths and channels as well as Ethernet ports is performed using PVC, IPoA route, Ethernet port enable, and Ethernet subgroups, the same group.

Also, DSLAM D-Link DAS-3248EC allows an administrator to uniformly manage the remote switch. One can set the corresponding parameters in Remote DSLAM subgroup, Deployment & Configuration group.

Management of access lists of channel level is carried out using subgroups in Filter & Access Control Configuration group.

One should use IRL Profile, Scheduled Profile, and QoS Setting - Upstream subgroups or QoS Setting - Downstream subgroup of the same-named group in order to manage the service performance.

Management of network protocols and multicast is carried out using subgroups in Protocol Configuration group.

If it's necessary, an administrator can test the physical line using subgroups in Diagnostic & Bin Information group.

That's where we bring to a close a brief review of the web-interface capabilities of the device. Now let's have a look at the device command line.

Command line

In order to access the command line through Telnet protocol one must use the same log-on information as for the connection to the device web-interface.

*******************
Welcome to DAS-3248/E
*******************
Software Release: R2.55 Date: Mar 5 2010
Copyright (c) 2008 D-Link Corporation
login: Admin
password:
Login Successful
$?
Command Description
------- -----------
alias To Alias a command
apply Apply configuration/image file
climode Modes of cli/Prio change of CLI task
commit Commit the active config to the flash
create Create a new entry of specified type
defragment Defragment the compact blocks in flash
delete Delete the specified entry
download Download a file on to the Device
exit To exit the CLI shell
get Display info for the search
help Provides help
list List files
memset Memset
modify Modify information for specified entry
passwd To modify user password
permission Change Permission of files
ping The normal ping command
rdf Read Flash
rdm Read Memory
reboot Reboot the device
remove Remove file
reset Reset info for the specified entry
sync Sync
traceroute The normal traceroute command
unalias To undefine previously defined alias
upgrade Upgrade
upload Upload a file on to the Device
verbose Switch ON/OFF the verbose mode
wrm Write Memory
$

We will not review all capabilities of the switch command line in detail but examine only some of them.

User creation is carried out using create user name test passwd test command, which we used to create a user named test and assigned it password test.

$create user name test passwd test
Entry Created
$ger user
Error: Invalid command
$
$get user
Privilege UserName
------------------
root Admin
user test

All commands with create prefix are used to create or add certain entries.

$create ?
Command Description
------- -----------
acl ACL Commands
aggr AGGR Commands
arp ARP Commands
atm ATM Commands
bridge BRIDGE Commands
clfr CLFR Commands
ctlpkt CTLPKT Commands
dra DRA Commands
dsl DSL Commands
eoa EOA Commands
ethernet ETHERNET Commands
filter FILTER Commands
ia IA Commands
igmpsnoop IGMPSNOOP Commands
ip IP Commands
ipoa IPOA Commands
ipoe IPOE Commands
irl IRL Commands
lacp LACP Commands
macprofile MACPROFILE Commands
mirror MIRROR Commands
pia PIA Commands
pppoe PPPOE Commands
pppr PPPR Commands
profile PROFILE Commands
rdncy RDNCY Commands
rdslam RDSLAM Commands
resvdmac RESVDMAC Commands
rid RID Commands
rl RL Commands
sched SCHED Commands
snmp SNMP Commands
sntp SNTP Commands
srmon Remote Monitoring Commands
trfclass TRFCLASS Commands
user System User Configuration
vlan VLAN Commands

An administrator can find out interface statuses and their configuration using get interface stats and get interface config commands (the command output is shortened).

$get interface stats
Interface : eth-1 Description : eth-1
Type : ETHERNET Mtu : 1500
Bandwidth : 0 Phy Adddr : 34:08:04:E1:F3:AF
Last Change(sec) : 0 Unknown Prot Pkts : 0
Admin Status : Up Operational Status : Down
In Octets : 0 Out Octets : 0
In Discards : 0 Out Discards : 0
In Errors : 0 Out Errors : 0
In Ucast Pkts : 0 Out Ucast Pkts : 0
In Mcast Pkts : 0 Out Mcast Pkts : 0
In Bcast Pkts : 0 Out Bcast Pkts : 0
LinkUpDnTrapEnable : Enable Promiscous Mode : True
Connector Present : True CounterDiscontTime : 0
HC In Octets : 0x000000000
HC OutOctets : 0x000000000
Interface : eth-2 Description : eth-2
Type : ETHERNET Mtu : 1500
Bandwidth : 0 Phy Adddr : 34:08:04:E1:F3:B0
Last Change(sec) : 0 Unknown Prot Pkts : 0
Admin Status : Up Operational Status : Down
In Octets : 0 Out Octets : 0
In Discards : 0 Out Discards : 0
In Errors : 0 Out Errors : 0
In Ucast Pkts : 0 Out Ucast Pkts : 0
In Mcast Pkts : 0 Out Mcast Pkts : 0
In Bcast Pkts : 0 Out Bcast Pkts : 0
LinkUpDnTrapEnable : Enable Promiscous Mode : True
Connector Present : True CounterDiscontTime : 0
HC In Octets : 0x000000000
HC OutOctets : 0x000000000
Interface : eth-3 Description : eth-3
Type : ETHERNET Mtu : 1500
Bandwidth : 1000000000 Phy Adddr : 34:08:04:E1:F3:B1
Last Change(sec) : 0 Unknown Prot Pkts : 0
Admin Status : Up Operational Status : Up
In Octets : 0 Out Octets : 0
In Discards : 0 Out Discards : 0
In Errors : 0 Out Errors : 0
In Ucast Pkts : 0 Out Ucast Pkts : 0
In Mcast Pkts : 0 Out Mcast Pkts : 0
In Bcast Pkts : 0 Out Bcast Pkts : 0
LinkUpDnTrapEnable : Enable Promiscous Mode : True
Connector Present : True CounterDiscontTime : 0
HC In Octets : 0x000000000
HC OutOctets : 0x000000000
Interface : dsl-1 Description : dsl-1
Type : Adsl Mtu : 1500
Bandwidth : 0 Phy Adddr : 34:08:04:E1:F3:AF
Last Change(sec) : 0 Unknown Prot Pkts : 0
Admin Status : Up Operational Status : Down
In Octets : 0 Out Octets : 0
In Discards : 0 Out Discards : 0
In Errors : 0 Out Errors : 0
In Ucast Pkts : 0 Out Ucast Pkts : 0
In Mcast Pkts : 0 Out Mcast Pkts : 0
In Bcast Pkts : 0 Out Bcast Pkts : 0
LinkUpDnTrapEnable : Enable Promiscous Mode : False
Connector Present : True CounterDiscontTime : 0
HC In Octets : 0x000000000
HC OutOctets : 0x000000000
Interface : dsli-1 Description : dsli-1
Type : Interleaved Mtu : 0
Bandwidth : 0 Phy Adddr : 00:00:00:00:00:00
Last Change(sec) : 0 Unknown Prot Pkts : 0
Admin Status : Down Operational Status : Down
In Octets : 0 Out Octets : 0
In Discards : 0 Out Discards : 0
In Errors : 0 Out Errors : 0
In Ucast Pkts : 0 Out Ucast Pkts : 0
In Mcast Pkts : 0 Out Mcast Pkts : 0
In Bcast Pkts : 0 Out Bcast Pkts : 0
LinkUpDnTrapEnable : Disable Promiscous Mode : False
Connector Present : True CounterDiscontTime : 0
HC In Octets : 0x000000000
HC OutOctets : 0x000000000
Interface : dslf-1 Description : dslf-1
Type : Fast Mtu : 0
Bandwidth : 0 Phy Adddr : 00:00:00:00:00:00
Last Change(sec) : 0 Unknown Prot Pkts : 0
Admin Status : Down Operational Status : Down
In Octets : 0 Out Octets : 0
In Discards : 0 Out Discards : 0
In Errors : 0 Out Errors : 0
In Ucast Pkts : 0 Out Ucast Pkts : 0
In Mcast Pkts : 0 Out Mcast Pkts : 0
In Bcast Pkts : 0 Out Bcast Pkts : 0
LinkUpDnTrapEnable : Disable Promiscous Mode : False
Connector Present : True CounterDiscontTime : 0
HC In Octets : 0x000000000
HC OutOctets : 0x000000000
Interface : atm-1 Description : atm-1
Type : ATM Mtu : 48
Bandwidth : 0 Phy Adddr : 00:00:00:00:00:00
Last Change(sec) : 50 Unknown Prot Pkts : 0
Admin Status : Up Operational Status : Down
In Octets : 0 Out Octets : 0
In Discards : 0 Out Discards : 0
In Errors : 0 Out Errors : 0
In Ucast Pkts : 0 Out Ucast Pkts : 0
In Mcast Pkts : 0 Out Mcast Pkts : 0
In Bcast Pkts : 0 Out Bcast Pkts : 0
LinkUpDnTrapEnable : Disable Promiscous Mode : False
Connector Present : False CounterDiscontTime : 0
HC In Octets : 0x000000000
HC OutOctets : 0x000000000
Interface : aal5-1 Description : aal5-1
Type : AAL5 Mtu : 1536
Bandwidth : 0 Phy Adddr : 00:00:00:00:00:00
Last Change(sec) : 51 Unknown Prot Pkts : 0
Admin Status : Up Operational Status : Down
In Octets : 0 Out Octets : 0
In Discards : 0 Out Discards : 0
In Errors : 0 Out Errors : 0
In Ucast Pkts : 0 Out Ucast Pkts : 0
In Mcast Pkts : 0 Out Mcast Pkts : 0
In Bcast Pkts : 0 Out Bcast Pkts : 0
LinkUpDnTrapEnable : Disable Promiscous Mode : False
Connector Present : False CounterDiscontTime : 0
HC In Octets : 0x000000000
HC OutOctets : 0x000000000
Interface : eoa-1 Description : eoa-1
Type : EOA Mtu : 1500
Bandwidth : 0 Phy Adddr : 00:00:00:00:00:00
Last Change(sec) : 0 Unknown Prot Pkts : 0
Admin Status : Up Operational Status : Down
In Octets : 0 Out Octets : 0
In Discards : 0 Out Discards : 0
In Errors : 0 Out Errors : 0
In Ucast Pkts : 0 Out Ucast Pkts : 0
In Mcast Pkts : 0 Out Mcast Pkts : 0
In Bcast Pkts : 0 Out Bcast Pkts : 0
LinkUpDnTrapEnable : Disable Promiscous Mode : True
Connector Present : False CounterDiscontTime : 0
HC In Octets : 0x000000000
HC OutOctets : 0x000000000

System information can be displayed by using get system command group.

$get system version
Control Plane Binary : R2.55
Data Plane Binary : DP_B02_10_28_04_ip1000a
$get system info
Description : DAS-3248/E
Name :
This email address is being protected from spambots. You need JavaScript enabled to view it.
Location : No.289, Sinhu 3rd Road, Neihu District, Taipei, Taiwan.
Contact :
This email address is being protected from spambots. You need JavaScript enabled to view it.
Vendor : No.289, Sinhu 3rd Road, Neihu District, Taipei, Taiwan.
LogThreshold : 0
Object-id : 1.3.6.1.4.1.3646.1300.19
Up Time(HH:MM:SS) : 41:56:14
HwVersion : 10
CPSwVersion : R2.55
DPSwVersion : DP_B02_10_28_04_ip1000a
System Time : Fri Jan 02 17:56:14 1970
Time Zone : GMT
DST : off
Services : physical datalink internet end-to-end applications
$get system manuf info
CpeUtopiaMode : Tx 16 Bit Rx 16 Bit
NetUtopiaMode : Tx 16 Bit Rx 16 Bit
CpeUtopiaMaster : False NetUtopiaMaster : True
MaxEthMacPhy : 3 ColumbiaIdSel : 18
CpeUtopiaFreq : 40 MHz
Eth Speed : 10 Mbps 100 Mbps 1000 Mbps
S.No | SelfMacAddr | EthPortIdSel | EthType
---------------------------------------------------
1 | 34:08:04:E1:F3:AF | 16 | Data
2 | 34:08:04:E1:F3:B0 | 17 | Data
3 | 34:08:04:E1:F3:B1 | 19 | Mgmt
Dsl manuf Text Info
---------------------
Num of LBRams : 2 Num of Chips : 2
Num of Ports : 24 Interface Type : Host Bus
Chip Type : G24
Serial Number : A10C8027034
Vendor Id : FFB5GSPN
Version Number : R2.*
Chip No Base Addr LBRam
-------------------------------
1 0x84a00000 0
2 0x84a00c00 1
Logical To Physical Port Mapping
--------------------------------
[ 0 - 7 ] 47 46 45 44 43 42 41 40
[ 8 - 15 ] 39 38 37 36 35 34 33 32
[ 16 - 23 ] 31 30 29 28 27 26 25 24
[ 24 - 31 ] 23 22 21 20 19 18 17 16
[ 32 - 39 ] 15 14 13 12 11 10 9 8
[ 40 - 47 ] 7 6 5 4 3 2 1 0
UART manuf Text Info
---------------------
Num of UARTs : 1
HSSL Port Id : 4 BaudRate : 9600
Data Bits : 8 Stop Bit : 1
Parity : None UART Mode : Interrupt
Application Type : console

In general, one can receive certain type of information using get command group, while by putting in delete commands one can delete it.

$get ?
Command Description
------- -----------
acl ACL Commands
actstdby ACTSTDBY Commands
adsl ADSL Commands
aggr AGGR Commands
arp ARP Commands
atm ATM Commands
autoupdate Autoupdate Status
bridge BRIDGE Commands
cbuftrace CBUFTRACE Commands
clfr CLFR Commands
cli CLI Commands
ctlpkt CTLPKT Commands
dhcp DHCP Commands
dot3 DOT3 Commands
dra DRA Commands
dsl DSL Commands
eoa EOA Commands
ethernet ETHERNET Commands
filter FILTER Commands
gvrp GVRP Commands
ia IA Commands
icmp ICMP Commands
igmpsnoop IGMPSNOOP Commands
interface Interface Commands
io IO Commands
ip IP Commands
ipoa IPOA Commands
ipoe IPOE Commands
irl IRL Commands
lacp LACP Commands
macprofile MACPROFILE Commands
mirror MIRROR Commands
nbsize NBSIZE Commands
oam OAM Commands
pia PIA Commands
pppoe PPPOE Commands
pppr PPPR Commands
profile PROFILE Commands
rdncy RDNCY Commands
rdslam RDSLAM Commands
resvdmac RESVDMAC Commands
rid RID Commands
rl RL Commands
rmon RMON Commands
rstp RSTP Commands
sched SCHED Commands
snmp SNMP Commands
sntp SNTP Commands
srmon Remote Monitoring Commands
stp STP Commands
system System Related Information
tcp TCP Commands
trace Trace/Log Commands
traps Trap Log Table
trfclass TRFCLASS Commands
user System User Configuration
vlan VLAN Commands
$delete ?
Command Description
------- -----------
acl ACL Commands
aggr AGGR Commands
arp ARP Commands
atm ATM Commands
bridge BRIDGE Commands
clfr CLFR Commands
ctlpkt CTLPKT Commands
dra DRA Commands
dsl DSL Commands
eoa EOA Commands
ethernet ETHERNET Commands
filter FILTER Commands
ia IA Commands
igmpsnoop IGMPSNOOP Commands
ip IP Commands
ipoa IPOA Commands
ipoe IPOE Commands
irl IRL Commands
lacp LACP Commands
macprofile MACPROFILE Commands
mirror MIRROR Commands
pia PIA Commands
pppoe PPPOE Commands
pppr PPPR Commands
profile PROFILE Commands
rdncy RDNCY Commands
rdslam RDSLAM Commands
resvdmac RESVDMAC Commands
rid RID Commands
rl RL Commands
sched SCHED Commands
snmp SNMP Commands
sntp SNTP Commands
srmon Remote Monitoring Commands
tcp TCP Commands
trfclass TRFCLASS Commands
user System User Configuration
vlan VLAN Commands

To modify some parameters one must use modify commands.

$modify ?
Command Description
------- -----------
acl ACL Commands
actstdby ACTSTDBY Commands
adsl ADSL Commands
aggr AGGR Commands
atm ATM Commands
autoupdate Autoupdate Status
bridge BRIDGE Commands
clfr CLFR Commands
cli CLI Commands
ctlpkt CTLPKT Commands
dra DRA Commands
eoa EOA Commands
ethernet ETHERNET Commands
filter FILTER Commands
gvrp GVRP Commands
ia IA Commands
igmpsnoop IGMPSNOOP Commands
interface Interface Commands
io IO Commands
ip IP Commands
ipoa IPOA Commands
ipoe IPOE Commands
irl IRL Commands
lacp LACP Commands
mirror MIRROR Commands
nbsize NBSIZE Commands
oam OAM Commands
pia PIA Commands
pppoe PPPOE Commands
pppr PPPR Commands
profile PROFILE Commands
rdncy RDNCY Commands
rdslam RDSLAM Commands
rl RL Commands
rstp RSTP Commands
sched SCHED Commands
snmp SNMP Commands
sntp SNTP Commands
stp STP Commands
system System Related Information
trace Trace/Log Commands
trfclass TRFCLASS Commands
vlan VLAN Commands

To troubleshoot network operation an administrator must put in ping and traceroute commands.

$ping 192.168.1.2
64 bytes of data from 192.168.1.2, seq=0 ttl=128 rtt =20 msec
64 bytes of data from 192.168.1.2, seq=1 ttl=128 rtt =10 msec
64 bytes of data from 192.168.1.2, seq=2 ttl=128 rtt =10 msec
64 bytes of data from 192.168.1.2, seq=3 ttl=128 rtt =40 msec
-------------------- Ping Statistics --------------------
4 packets transmitted, 4 packets received, 0 percent packet loss

To see the list of files located on the device memory, one must use list command.

$list
Flash size : 7340032
Flash Block size : 131072
Free Blocks in Flash : 16
/nvram/bin/control/
Name : CP.bin.gz
Version : 1 Size(bytes) : 3257468
Time : Fri Mar 5 10:51:29 2010
Permission : RW State : active
Used Blocks : 25
/nvram/bin/dataplane/
Name : DP.bin.gz
Version : 1 Size(bytes) : 386284
Time : Fri Mar 5 10:51:29 2010
Permission : RW State : active
Used Blocks : 3
/nvram/bin/dslphy/
Name : dsl_10_330000003C00000D.bin.gz
Version : 1 Size(bytes) : 266376
Time : Fri Mar 5 10:51:29 2010
Permission : RW State : active
Used Blocks : 3
/nvram/cfg/factorydef/
Name : FD.cfg
Version : 1 Size(bytes) : 6801
Time : Fri Mar 5 10:51:29 2010
Permission : RW State : active
Used Blocks : 1
Name : FD.cfg
Version : 2 Size(bytes) : 5987
Time : Fri Mar 5 10:51:29 2010
Permission : RW State : inactive
Used Blocks : 1
/nvram/cfg/manuf/
Name : Manuf.txt
Version : 1 Size(bytes) : 6301
Time : Fri Mar 5 10:51:29 2010
Permission : RW State : active
Used Blocks : 1
/nvram/system/
Name : CFG1
Version : 1 Size(bytes) : 262032
Time :
Permission : SYS State : active
Used Blocks : 2

That's where we draw the brief review of the device command line to a close.

SNMP-access

An administrator can pit the access to the ADSL switch on in SNMP community, SNMP host and SNMP trap host subgroups, Deployment & Configuration group of the web-interface.

Any software which is compatible with the second version of the protocol can be used to gain access to the device through SNMP. In order to review the device information we used Getif utility, 2.3.1 version.

It is not only through the command line or web-interface the device management can be carried out; D-Link offers a single-purpose utility, D-Link DAS, which is used for connection to DAS-3248EC.

The above-named utility provides an administrator with the similar device control features as the command line or web-interface do.

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 protocol. DSLAM D-Link DAS-3248EC boots in 66 seconds.

The next thing we usually do is conducting a security scanning procedure, which has been carried out using Positive Technologies XSpider 7.7 (Demo build 3100) utility. This review is not the exception, D-Link DAS-3248EC has five open ports: TCP-23 (Telnet), TCP-69 (TFTP), UDP-69 (TFTP), TCP-80 (HTTP) and TCP-100 (Telnet). The most interesting data, which we received as a result of scanning, are presented below.

Now we will pass on to testing the network access speeds of ADSL clients. Two wireless ADSL routers were used to test it: D-Link DSL-2750U and ASUS DSL-N12U. The primary specifications of the test stand we used are presented below.

Component PC Notebook
Motherboard ASUS Maximus V Extreme ASUS M60J
CPU Intel Core i7 3770K 3.5 GHz Intel Core i7 720QM 1.6 GHz
RAM DDR3 PC3-10700 SEC 32 Gbytes DDR3 PC3-10700 SEC 16 Gbytes
NIC Intel Gigabit CT Desktop Adapter Atheros AR8131
OS Windows 7 x64 SP1 Rus Windows 7 x64 SP1 Rus

We have tested three different operation modes of the switch; results of the measurements are presented below.

DSLAM D-Link DAS-3248EC allows limiting physical speeds at which the client devices can get connected to the switch. We decided to test how exactly the stated and real speeds correspond. On the diagram presented below we were changing the physical speed from 0.5 Mbps until 20 Mbps in steps of 0.5 Mbps. The tests were carried out for downstream flows with 10 concurrent TCP connections. D-Link DSL-2750U wireless router has been used as the client device.

Now let's pass on to summing it all up.

Conclusion

D-Link DAS-3248EC entry-level ADSL switch we have tested made a good impression on us. The device allows connecting up to 48 subscribers providing them with broadband access to IP-networks using present telephone-based infrastructure. Device dimensions make it possible to place it even in the fully-packed communication racks.

The strength areas of the device are presented below.

  • Support of Annex L and Annex M
  • 1U case
  • Competitive price
  • Support of multicast traffic
  • QoS maintenance mechanisms
  • Ethernet interface grouping is supported
  • Support of virtual stacking

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

  • Cross-functional brackets for 19-inch and 23-inch racks can make a mounting process to 19-inch racks a bit more difficult
  • Neither Telco-50<->RJ-11 cables nor adapters are included
  • The web-interface is a bit laggy
  • Lack of a redundant power supply

As of when this article was being written, the average price for a DSLAM D-Link DAS-3248EC in Moscow online shops was 65000 roubles.

http://www.icplus.com.tw/

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