Important ADSL Parameter

SNR Margin

SNR Margin is the difference between actual SNR on the line and the SNR needed for a particular sync-rate or bandwidth. For example, if the actual SNR is 45 dB and the SNR needed to maintain sync-rate at 2 Mbps is 20 dB. Then the SNR margin is 25 dB.

Consistent SNR Margin is essential to absorb fluctuations in interference on the line, and is therefore meant to keep the service stable. SNR Margin is applicable to both upstream and downstream.

Rule of thumb 1:

SNR Margin

Remarks


6 db or below

Poor and subscriber wont be able to sync, intermittent sync problems or any connectivity issue.


7 dB – 10 dB

Fair but does not leave much room for variances in copper line conditions.


11 dB – 20 dB

Good with little or no sync problems


20 dB – 28 dB

Excellent


29 dB or above

Outstanding


Increasing sync-rate by 1 Mbps will reduce SNR margin by approximately 5 dB.

Rule of thumb 2 :

There are two ways to increase SNR Margin:

It is recommended to isolate and remove external source of noise or interference.

· Parallel lines can considerably reduce noise margin and also introduce impulse noise when phone rings or during calls.

· Power lines causing inductive interference especially inside the premise.

· Poor quality drop wire or internal wiring. (Normally can be inspected by the quality of the insulator).

· Poor quality cable pair.

· Improper patching at MDF, Cabinet or DP.

Short-term fix can be done by reducing ADSL sync-rate until SNR level reaches acceptable value.

SNR Margin value can be obtained from modem, ADSL test gear, EMS and BMS.



Attenuation

Attenuation is the amount of transmits power loss due to line impedance and is generally proportional to the length of cable. The maximum operational limit to initiate and maintain synchronization is 65 dB.

under mixed gauge cable environment, usually 13.6 dB loss per kilometer is used to estimate distance.



Rule of thumb:

The attenuation value can be obtained from modem, ADSL test gear, EMS and BMS.



TM guideline for SNR Margin & attenuation:

ADSL Speed

SNR Margin

(Upstream & Downstream)

Attenuation (Downstream)


512 kbps

> 12 dB

< 60 dB


1 Mbps

> 12 dB

< 55 dB

1.5 Mbps

> 13 dB

< 48 dB


2 Mbps

> 15 dB

< 40 dB


4 Mbps

> 15 dB

< 30 dB

Throughput

Throughput is the amount of data moved successfully from one place (e.g., your computer) to another (e.g., any given website on the Internet) in a given time period.

A throughput test is done by downloading and/or uploading a file (depending on the measurement type selected). Download throughput is calculated by taking the file size downloaded and dividing by the time taken to download. Upload throughput is calculated by taking the file size uploaded and divided by the time taken to upload.

Throughput can be obtained from TM Net Speedometer or http://www.izzi.com.my/speedtest.

Accurate Streamyx Bandwidth Test

Click =>Start-Run-command

ftp ftp2.tm.net.my
Connected to ftp2.tm.net.my.
220 FTP Server ready
User (ftp2.tm.net.my:(none)): anonymous
331 Guest login ok, send your complete e-mail address as password.
Password:test@yahoo.com
230-You are user #2 of 250 simultaneous users allowed.
230-
230-######################################################
230-# #
230-# Welcome to ftp.tm.net.my #
230-# Only .zip & .rar are allowed to be uploaded #
230-# Make sure they are password-protected #
230-# #
230-######################################################
230-
230 Logged in anonymously.
ftp> cd incoming
250 "/incoming" is new cwd.
ftp> hash
Hash mark printing On ftp: (2048 bytes/hash mark) .
ftp> bin
200 Type okay.
ftp> mget winzip81.exe
200 Type okay.
mget xishu.mp3? y
200 PORT command successful.
150 Opening BINARY mode data connection for winzip81.exe (4386612 bytes).
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226 Transfer completed.
ftp: 4386612 bytes received in 21.41Seconds 204.92Kbytes/sec.
ftp>bye


How to calculate downstream speed
Result 204.92 x 8 = 1639 in kilobits /sec = 1.639Mbps

STREAMYX ADSL MODEM LOGIN : DEFAULT PASSWORD

D-Link DSL504T
username admin
password admin
IP 192.168.1.1

Tecom AR1031
username admin
password admin
IP 192.168.1.1

netlink adsl router
username admin
password conexant
IP 10.0.0.2

prolink hurricane 9000p
username admin
password password
IP 10.0.0.2

SMC barricade smc7904bra
username
password smcadmin
IP 192.168.2.1

TRENDnet TDM E300+
username DSL
password DSL
IP 192.168.1.1

Aztech DSL600ER
username admin
password admin
IP 192.168.1.1

ZTE modem
IP Address: 192.168.1.1
Username: ADSL
Password: expert03
Username: ZXDSL
Password: ZXDSL
Username: admin
Password: telekomst

KASDA modem:
IP Address: 192.168.1.1
Username: admin
Password: telekomst

ArtNet modem:
IP Address: 192.168.1.1
Username: admin
Password: telekomst
Username: admin
Password: admin
Username: admin
Password: password

Triz modem:
IP Address: 192.168.1.1
Username: admin
Password: aaaaaaaa

Aztech modem:
IP Address: 10.0.0.2 OR 192.168.1.1
Username: admin
Password: blank
Username: admin
Password: password
Username: admin
Password: admin

Billion modem:
IP Address: 192.168.1.254
Username: admin
Password: password

Huawei modem:
IP Address: 192.168.1.1
Username: admin
Password: admin

Hyundai HSE-220 Modem:
IP Address: 192.168.1.1
Username: ADSL
Password: ADSL
Username: admin
Password: ADSL
Username: root
Password: root

Riger DB102:
IP Address: 192.168.1.1
Username: tmadmin
Password: tmadmin

TP-LINK MODEM / ADSL2 / ROUTER:
IP Address: 192.168.1.1
Username: admin
Password: admin

db102 ADSL2 modem (Riger Corp.)
username : tmadmin
password : tmadmin