Currently experiencing DSL problems

[IllegalOperation]

My DSL internet access was intermittently going up and down today. More specifically, I have an 827 router - and I noticed that the ATM interface is "flapping". It is totally sperratic, and is not time sensitive. One second it is up, the next it is down.

I have ran debug commands like crazy, and have come up with very little. I noticed that I am getting CRC and header errors on the ITU G.992.1 side. Doing a debug ATM error gives an output of this error message....


DSL: Defect: LOS LOF LCDf: retraining
%LINK-3-UPDOWN: Interface ATM0, changed state to down
%LINEPROTO-5-UPDOWN: Line protocol on Interface ATM0, chan
ged state to down


Ive noticed that whatever is causing the errors on my router, it is at times forcing my ATM interface down (as you can see with the debug message). I even noticed that my PAP handshake is getting denied a couple times when the ATM tries to come back up again. I think that is only because the PAP session is possibly getting interrupted.

The problem isnt the ISP, because their tests have passed. I know the problem looks like a bad line (too much noise perhaps), but I never experienced this until I put in this Cisco 827. Before I had a simple Efficient Networks router.

If the problem isnt physical, then it has to be at the ATM/PPP communications layer - as that is where all my errors are originating from. Anyone have any experience in troubleshooting DSL links? Ill post some debug messages on the next reply. Appreciated...

 

[IllegalOperation]

This is a debug ATM errors and events. Also a debug PPP errors, events, and authentication.....

*Mar 1 00:15:01.987: Vi1 PAP: I AUTH-NAK id 7 len 18 msg is "Access Denied"
*Mar 1 00:15:04.367: %DIALER-6-UNBIND: Interface Vi1 unbound from profile Di1
*Mar 1 00:15:04.371: Vi1 PPP: Authorization NOT required
*Mar 1 00:15:04.371: %LINK-3-UPDOWN: Interface Virtual-Access1, changed state t
o down
*Mar 1 00:15:04.375: Vi1 Debug: Condition 2, interface Di1 cleared, count 0
*Mar 1 00:15:26.415: Vi1 Debug: Condition 2, interface Di1 triggered, count 1
*Mar 1 00:15:26.415: %DIALER-6-BIND: Interface Vi1 bound to profile Di1
*Mar 1 00:15:26.415: Vi1 PPP: Treating connection as a callout
*Mar 1 00:15:26.419: Vi1 PPP: Authorization NOT required
*Mar 1 00:15:26.419: %LINK-3-UPDOWN: Interface Virtual-Access1, changed state t
o up
*Mar 1 00:15:26.423: Vi1 PPP: Treating connection as a callout
*Mar 1 00:15:26.443: Vi1 PAP: O AUTH-REQ id 8 len 41 from "yessydo@static_ameri
tech.net"
*Mar 1 00:15:28.051: Vi1 PAP: I AUTH-NAK id 8 len 18 msg is "Access Denied"
*Mar 1 00:15:30.051: %DIALER-6-UNBIND: Interface Vi1 unbound from profile Di1
*Mar 1 00:15:30.055: Vi1 PPP: Authorization NOT required
*Mar 1 00:15:30.055: %LINK-3-UPDOWN: Interface Virtual-Access1, changed state t
o down
*Mar 1 00:15:30.059: Vi1 Debug: Condition 2, interface Di1 cleared, count 0
*Mar 1 00:15:38.855: DSL: Defect: LOS LOF LCDf: retraining
*Mar 1 00:15:41.843: %LINK-3-UPDOWN: Interface ATM0, changed state to down
*Mar 1 00:15:42.843: %LINEPROTO-5-UPDOWN: Line protocol on Interface ATM0, chan
ged state to down
*Mar 1 00:16:00.347: %LINK-3-UPDOWN: Interface ATM0, changed state to up
*Mar 1 00:16:01.347: %LINEPROTO-5-UPDOWN: Line protocol on Interface ATM0, chan
ged state to up
*Mar 1 00:16:02.091: Vi1 Debug: Condition 2, interface Di1 triggered, count 1
*Mar 1 00:16:02.091: %DIALER-6-BIND: Interface Vi1 bound to profile Di1
*Mar 1 00:16:02.095: Vi1 PPP: Treating connection as a callout
*Mar 1 00:16:02.095: Vi1 PPP: Authorization NOT required
*Mar 1 00:16:02.095: %LINK-3-UPDOWN: Interface Virtual-Access1, changed state t
o up
*Mar 1 00:16:02.099: Vi1 PPP: Treating connection as a callout
*Mar 1 00:16:02.123: Vi1 PAP: O AUTH-REQ id 9 len 41 from "yessydo@static_ameri
tech.net"
*Mar 1 00:16:03.583: Vi1 PAP: I AUTH-ACK id 9 len 5
*Mar 1 00:16:04.583: %LINEPROTO-5-UPDOWN: Line protocol on Interface Virtual-Ac
cess1, changed state to up
*Mar 1 00:16:13.975: %LINEPROTO-5-UPDOWN: Line protocol on Interface Tunnel0, c
hanged state to up
*Mar 1 00:17:02.691: DSL: Defect: LOS LOF LCDf LOM: retraining
*Mar 1 00:17:05.363: %LINK-3-UPDOWN: Interface ATM0, changed state to down
*Mar 1 00:17:06.363: %LINEPROTO-5-UPDOWN: Line protocol on Interface ATM0, chan
ged state to down


This is a show dsl interface ATM 0 (note the high amount of CRCs, this was only after an uptime of a couple minutes)...

ATU-R (DS) ATU-C (US)
Modem Status: Showtime (DMTDSL_SHOWTIME)
DSL Mode: ITU G.992.1 (G.DMT)
ITU STD NUM: 0x01 0x1
Vendor ID: 'ALCB' 'ALCB'
Vendor Specific: 0x0000 0x0000
Vendor Country: 0x00 0x0F
Capacity Used: 70% 60%
Noise Margin: 9.5 dB 16.0 dB
Output Power: 18.0 dBm 12.0 dBm
Attenuation: 54.5 dB 31.5 dB
Defect Status: None None
Last Fail Code: None
Selftest Result: 0x00
Subfunction: 0x02
Interrupts: 356302 (2 spurious)
Activations: 48
SW Version: 3.670
FW Version: 0x1A04

Interleave Fast Interleave Fast
Speed (kbps): 0 1536 0 384
Reed-Solomon EC: 0 0 0 0
CRC Errors: 0 6408 0 0
Header Errors: 0 1179 0 0
Bit Errors: 0 0
BER Valid sec: 0 0
BER Invalid sec: 0 0

---------------------------------------------------------------
MODEM INITIALIZING IN OPERATION MODE G_DMT POTS !!!!!
INITIALIZATION SPECIFICATIONS : STANDARD COMPLIANT INITIATIZATION !!!!!
INITIALIZATION SPECIFICATIONS : MINUMUM OVERHEAD FRAMING !!!!!
---------------------------------------------------------------
build R_MESSAGES1
New PILOT has carrier number 61
force counter reload
TransmitSequence: Counter reload event
Calculate final TEQ
Calculate final window move
TEQ-FEQ : DcOffset value : 5.527863502502441406e1
starttim 4, 0x4C228 RTV value for segue detection : 129
stoptim: 4 , 0x4C228
FELOS OFF
TX BITSWAP REQUEST ...
Total TX Power : 21.652
starttim 6, 0x4C264stoptim: 6 , 0x4C264
done at sync 141 and symb 0

 

[commsguy]

LOS, LOF are framing/signalling errors, make sure your settings match the carrier. make sure you have the right signalling protocol assigned.

commsguy

http://www.convetech.com

 

[IllegalOperation]

Thanks commsguy. I thought the only information needed from the provider (besides username/password), is the VCI/VPI. Do I have to contact my provider for their signalling information, or is there another way of obtaining it? Also, where in the router do I need to go to check the signaling information, and change it accordingly?