Cisco 1802 - DSLAM problem

Unanswered Question
Oct 31st, 2007


i have a problem with a cisco 1802 router.When i connect the router to the ADSL line, the CD led is green but the router cant authenticate with the ISP.The ADSL line is 4532/768 Kbits. When i connect the router to a 1024/256 ADSL line (with the same configuration) the router connects with the ISP and the PPP led is green. The IOS ver is the c180x-adventerprisek9-mz.124-15.T1. The only i can think, is that when i see the dsl stats, the capacity usage for the uplink is at 100%.

Please help!

I have this problem too.
0 votes
  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 0 (0 ratings)
Paolo Bevilacqua Wed, 10/31/2007 - 13:44


if you are positive that the same configuration must work on both lines, check that you got an IP address assigned. Has been the line been completely provisioned by the ISP ?

papasot1978 Wed, 10/31/2007 - 13:59

The line is ok, because when i connect a very cheap router (ADSLoISDN)to the line it connects without any problem. The cisco cant obtain an IP, the Virtual Access protocol is down. I think is a problem with the compatibility with the local DSLAM or the router cant play with 4Mbit ADSL line (NOT ADSL2 or ADSL2+ line. Any ideas?

Paolo Bevilacqua Thu, 11/01/2007 - 06:16


the interface trains up OK and you have recent adsl FW.

Something else is working, please send config and "show atm pvc X/Y" whre X/y are your VPI/VCI values. If usuing PPP, also take "debug ppp nego" and "debug ppp auth" with "term mon".

papasot1978 Thu, 11/01/2007 - 10:34

The router with the exact same configuration works fine with an ADSL line (ANNEX B) at 1024/256 speed. The VPI/VCI are ok (8/35).I have send e-mail to the ISP and i 'm waiting for an answer.I think that the problem is the upload of the line(768).You can not buy from the provider a line at 4096/768,but a line at 4096/256 (readind the offers at the providers web page). Also the main telphone company in Greece (OTE) changes the DSLAMs to SIEMENS ones. It's very strange problem. The next time i will visit my customer i will have with me a cisco 876 to test again the line. Thank you very much! I will post the solution (if its possible) of the problem.


This Discussion