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New Member

Cisco SRP 527W ADSL 2+ Interesting Issue

Good Evening ,

Just posting an interesting experience I observed recently with regard to the Cisco 527W ADSL 2+ router.

Picture a site with a working ADSL2+ connection with a router from a different vendor working perfectly well with full sync. The region of this router is the UK.

A decision is made to deploy a Cisco 527W router to replace the existing router and so it is prepared and updated to the latest firmware prior to deployment as you normally would.

The router is taken to site and swapped with the working one and the new Cisco 527W does not even initiate a sync on the ADSL , no lights to indicate it detects the electrical signal from the line. Nothing in the GUI to indicate that is is even trying.

That router is then returned as faulty and another one comes in , this time the router is not firmware updated prior to installation and is plugged in at the site , the router then syncronises with the line ok. It is then firmware updated to the latest version which then kills its sync and it never tries again.

VC settings were checked

Modulation and encapsulation settings were checked

Different cables

Different filters etc

Roll back to old firmware(still dident work!)

The firmware version it was updated to was


Any suggestions as to why having the latest firmware on this model would cause it to break the ability to sync with UK based DSL would be appreciated.

Cisco Employee

Cisco SRP 527W ADSL 2+ Interesting Issue

Hi Mark,

There is no good reason at all why that shouldn't work. 

Which version was running before the upgrade?  I assume that you tried rebooting after the upgrade completed and that this didn't make any difference?

You can see additional DSL sync information via a hidden page in the GUI.  After logging in, change the page name in the URL to dsldiag.asp - you can force a retrain from here too.  Let me know what you find.



New Member

Re: Cisco SRP 527W ADSL 2+ Interesting Issue

Thanks for your reply Andrew , we did try restarting the router many times after the upgrade however there was no luck. Original firmware on the unit was as follows: Version: 1.01.09 (001) Apr 7 2010 .

We are currently getting another unit for testing and will take a look at the DSL diags at next test.

New Member

Re: Cisco SRP 527W ADSL 2+ Interesting Issue

As an additional note , we tested the router that was not working on the original site with the latest firmware(1.01.26) on a different ADSL 2+ line and it managed to sync up , it would appear that the combination of the router and an unknown chracteristic of that sites line mean that it will not initiate a sync however it does work with a router from a different vendor.

New Member

Re: Cisco SRP 527W ADSL 2+ Interesting Issue

Hi Mark,

Could you try with model SRP527W-U and firmware version 1.2.4?

Could you provide to us:

1) S/N signal of the line

2) Attenuation signal.

3) Type of the MUX (brand etc etc).

4) Configuration applied in the MUX

New Member

Re: Cisco SRP 527W ADSL 2+ Interesting Issue

Thanks for the reply Paolo , unfortunately I do not have access to the U model of that router to test with , however I can provide details from the router that is operating sucessfully on the line at present as well as posting information from the dsldiag page when we go back out and retest.

The line settings that are sucessfully in use at present with the other vendors router are as follows:

VC MUX Encapsulation

VPi 0
VCI 38

Protocol PPPoA
ADSL2+ G.992.5

SNR Margin 9

Loop Attenuation 17

Many Thanks

New Member

Cisco SRP 527W ADSL 2+ Interesting Issue

Just so you are aware , we managed to resolve the issue after further testing. We put the router in using its original firmware that it came with from 2010. Then took a configuration backup , firmware upgraded the router , the restored the configuration.

Following that the ADSL2+ light came up, There must have been some sort of issue with the configuration being corrupted when the firmware was updated.

Many Thanks for your responses.

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