Troubleshooting for Broadband Speed
List of Checks in Modem
1.LineSNR -----it must be stable and greater than -8db is preferred.
2.LineRate------Must be slightly higher than Plan speed
For example, 4Mbps plan line rate must be greater than 4400Kbps.
       otherwise customer will get 3.6Mbps only 
3.Annex-M dsl modulation
Set modem in ADSL2+ Annexure-M modulation to improve SNR.
For long distance connection use G.Dmt modulation.
4.Set DNS-relay-in-modem -- If DNS is set it will be relayed to wireless devices.
   (Normally it is available in LAN > DHCP setting)

5.Set DNS-in-PC
To improve browsing speed
To avoid page not found errors

6.Disable-WPS in Wireless
In DLink modem it is available in Advanced >wireless>WPS-Disable
In Tp-link it is available in Interface Setup>Wireless>"Use WPS=No"
This setting is very important to get rid of misuse of broadband.

7.a Deactivate-UPNP/CWMP/Tr069
universal plug and play UPNP normally available in "ADVANCED"
To avoid hacking from the internet.
   b. Activate 'ACL'
in adavanced menu to block modem access via internet

8.Use Best ,Secured and latest version browser.
Mozilla Firefox & ComodoDragon (very secured & uses own DNS)

9.Disable all Add-ONs except "java" and "Flash"

Following are examples of Junkwares to be removed:

  • Ask Toolbar
  • Babylon
  • Browser Manager
  • Claro / iSearch
  • Conduit
  • Coupon Printer for Windows
  • Crossrider
  •           Delta Search
  • Facemoods / Funmoods
  • iLivid
  • IncrediBar
  • MyWebSearch
  • Searchqu
  • Web Assistant
  • To remove all above junkwares use ADWCleaner
  • (

10.Install-HOST-file to block advertisements
Available in

11.Dslam Line Profile attached to the port (check line rate & SNR before book the case)
 Book a case to NiB to change line-profile thro

-Customer may choose a plan from 8Mbps to 24Mbps.
-Customers in old 2/4Mbps plan must be migrated to new PLANs
-Maximum download rate depends on line rate, SNR & BB-plan also.
-Upload depends on ADSL/VDSL modem and ANNEX-M mode.
In Annex-M mode we can go upto 2Mbps upload for ADSL modem.
For VDSL modem it can be upto 24Mbps.

13.MTU -Maximum transmission unit.
Normally the values are 1492,1452,1400 or 0
To verify MTU, open the site
The site will not load if MTU is wrong, if so try different values.
MTU problem mostly exist in Netgear,Belkins,Zyxel modems.

In some DSLAM will not load fast.
If so check the speed by playing youtube video, if no buffering, speed will be Ok.
If customer not convinced, change the indiactor to some other DSLAM (like sterlite/Huawei etc)
Please note that if speedtest site is full of advertisements, then install Host FILE first.

15.Disable-Apps in Win8/10 -Windows 8 and above installs many apps like weather, news,sports etc
Disable or uninstall these application to avoid interference in browing.

16.Dont use autoUpdate of windows/ Antivirus(set as manual update)
This is to avoid automatic downloading in background.
To disable autoupdate - RUN>services>windows update>disable

17.All above settings to be done in all PCs in a network environment.

18.Ping TEST the DSLAM for packet loss.
Test through NIB helpdesk portal Menu 4E

19.Trojan attack -Internet virus

Trojans normally attacked thro LAN adapter, Browser add ons and as a service
Indications of trojan attack:
a,Continuous flickering internet light when no browsing or downloading.
b,Close all internet apps like chrome, IE, firefox ,outlook etc
Now thro command prompt give the command - C:\ netstat  -an
This will list of connections established with foreign address.
Too many foreign address ie, more than 10 means PC may be attacked with Trojan.
Ignore foreign address in the range like 10.x.x.x ,127.x.x.x,192.x.x.x.

How to remove trojans ?
1. Disable startup application and restart.
2. Install malwarebytes software

20.Computer settings:
     a. Set DNS manually
     b. Uncheck all other tick marks except TCP4 in LAN Properties.
     c. Disable startup applications  Start > Run > msconfig
     d. Disable startup services Start >Run > msconfig >Services tab
                          > Check 'Hide all Microsoft apps' >disable all   

Finally call NIB in-charge for further help.