[c-nsp] MLPPP/T1 problems

Tue Sep 18 22:59:35 EDT 2007

Could it be a bad T1 controller?  Try swapping out the T1 card as well, if 
possible.

Otherwise, I tend to agree;  the cause of your problems as visualised on 
the PPP layer most likely is reducible to underlying physical issues on 
the physical framing layer.

On Tue, 18 Sep 2007, Chris Hale wrote:

> All -
>
> We have a 4xT1 MLPPP set up with a customer and yesterday it started giving
> us problems.  For some reason, our side is sending a termreq when the LCP
> session is set up, and PPP starts to come up:
>
> Sep 18 14:04:02.585 EDT: Se5/5:0 LCP: State is Open
> Sep 18 14:04:02.585 EDT: Se5/5:0 PPP: Phase is VIRTUALIZED [0 sess, 1 load]
> Sep 18 14:04:02.585 EDT: Se5/5:0 PPP: Phase is TERMINATING [0 sess, 1 load]
> Sep 18 14:04:02.585 EDT: Se5/5:0 LCP: O TERMREQ [Open] id 234 len 4
> Sep 18 14:04:02.589 EDT: Se5/5:0 LCP: I TERMACK [TERMsent] id 234 len 4
> Sep 18 14:04:02.589 EDT: Se5/5:0 LCP: State is Closed
> Sep 18 14:04:02.589 EDT: Se5/5:0 PPP: Phase is DOWN [0 sess, 1 load]
>
> I originally thought I had a MRRU issue:
>
> Sep 18 14:03:40.525 EDT: Se5/5:0 LCP: O CONFREQ [Listen] id 215 len 30
> Sep 18 14:03:40.525 EDT: Se5/5:0 LCP: MagicNumber 0xB0158457
> (0x0506B0158457)
> Sep 18 14:03:40.525 EDT: Se5/5:0 LCP: MRRU 1500 (0x110405DC)
> Sep 18 14:03:40.525 EDT: Se5/5:0 LCP: EndpointDisc 1 br-1bp-bos-ma
> (0x13100162722D3162702D626F732D6D61)
> Sep 18 14:03:40.529 EDT: Se5/5:0 LCP: I CONFREQ [REQsent] id 110 len 23
> Sep 18 14:03:40.529 EDT: Se5/5:0 LCP: MagicNumber 0x07CA49EA
> (0x050607CA49EA)
> Sep 18 14:03:40.529 EDT: Se5/5:0 LCP: MRRU 1524 (0x110405F4)
> Sep 18 14:03:40.529 EDT: Se5/5:0 LCP: EndpointDisc 1 Router
> (0x130901526F75746572)
> Sep 18 14:03:40.529 EDT: Se5/5:0 LCP: O CONFACK [REQsent] id 110 len 23
> Sep 18 14:03:40.529 EDT: Se5/5:0 LCP: MagicNumber 0x07CA49EA
> (0x050607CA49EA)
> Sep 18 14:03:40.529 EDT: Se5/5:0 LCP: MRRU 1524 (0x110405F4)
> Sep 18 14:03:40.529 EDT: Se5/5:0 LCP: EndpointDisc 1 Router
> (0x130901526F75746572)
> Sep 18 14:03:40.529 EDT: Se5/5:0 LCP: I CONFACK [ACKsent] id 215 len 30
> Sep 18 14:03:40.529 EDT: Se5/5:0 LCP: MagicNumber 0xB0158457
> (0x0506B0158457)
> Sep 18 14:03:40.529 EDT: Se5/5:0 LCP: MRRU 1500 (0x110405DC)
> Sep 18 14:03:40.529 EDT: Se5/5:0 LCP: EndpointDisc 1 br-1bp-bos-ma
> (0x13100162722D3162702D626F732D6D61)
>
> I fixed that even though both ends seemed to confack on (both?) the MRRU of
> 1500 and 1524.
>
> I've done a BERT test through my local CSU/DSU with no errors, but when I
> release the loopback, I start taking errors on the serial interface that
> increment every few seconds:
>
> Serial5/5:0 is up, line protocol is down
>  Hardware is Multichannel T1
>  Description: QJR-0004
>  MTU 1500 bytes, BW 1536 Kbit, DLY 20000 usec,
>     reliability 252/255, txload 1/255, rxload 1/255
>  Encapsulation PPP, crc 16, Data non-inverted
>  Keepalive set (10 sec)
>  LCP ACKsent, multilink Closed
>  Closed: CDPCP
>  Last input 00:00:14, output 00:00:00, output hang never
>  Last clearing of "show interface" counters 00:30:54
>  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
>  Queueing strategy: fifo
>  Output queue: 0/40 (size/max)
>  5 minute input rate 0 bits/sec, 0 packets/sec
>  5 minute output rate 0 bits/sec, 0 packets/sec
>     1187 packets input, 26083 bytes, 0 no buffer
>     Received 0 broadcasts (0 IP multicast)
>     299 runts, 0 giants, 0 throttles
>     299 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
>     1343 packets output, 35909 bytes, 0 underruns
>     0 output errors, 0 collisions, 0 interface resets
>     0 output buffer failures, 0 output buffers swapped out
>     0 carrier transitions
>  no alarm present
>  Timeslot(s) Used:1-24, subrate: 64Kb/s, transmit delay is 0 flags
>
> Here is the controller information:
>
> br-1bp-bos-ma#show controller t1 5/5 brief
> T1 5/5 is up.
>  Applique type is Channelized T1
>  Cablelength is long gain36 0db
>  Description: QJR-0004
>  No alarms detected.
>  alarm-trigger is not set
>  Framing is ESF, Line Code is B8ZS, Clock Source is Internal.
>  Data in current interval (608 seconds elapsed):
>     0 Line Code Violations, 0 Path Code Violations
>     0 Slip Secs, 0 Fr Loss Secs, 0 Line Err Secs, 0 Degraded Mins
>     0 Errored Secs, 0 Bursty Err Secs, 0 Severely Err Secs, 0 Unavail Secs
>  Total Data (last 18 15 minute intervals):
>     0 Line Code Violations, 0 Path Code Violations,
>     0 Slip Secs, 0 Fr Loss Secs, 0 Line Err Secs, 0 Degraded Mins,
>     0 Errored Secs, 0 Bursty Err Secs, 0 Severely Err Secs, 16 Unavail Secs
>
> We've opened a ticket with the telco who claims they test clean between
> their demarks, but they are seeing a yellow alarm from us.
>
> The only thing I can think of is a bad cable from the telco demark to our
> end.  Thoughts??
>
> interface Serial5/5:0
> description QJR-0004
> no ip address
> encapsulation ppp
> no fair-queue
> ppp authorization NOAUTH
> ppp multilink
> ppp multilink mrru local 1524
> multilink-group 6
> no clns route-cache
>
> controller T1 5/5
> framing esf
> clock source internal
> linecode b8zs
> channel-group 0 timeslots 1-24
> description QJR-0004
>
> Cisco IOS Software, 7200 Software (C7200-IK91S-M), Version 12.2(25)S7,
> RELEASE SOFTWARE (fc1)
> Technical Support: http://www.cisco.com/techsupport
> Copyright (c) 1986-2005 by Cisco Systems, Inc.
> Compiled Fri 28-Oct-05 09:12 by pwade
>
> ROM: System Bootstrap, Version 12.2(4r)B, RELEASE SOFTWARE (fc1)
> BOOTLDR: 7200 Software (C7200-BOOT-M), Version 12.0(24)S, EARLY DEPLOYMENT
> RELEASE SOFTWARE (fc1)
>
> br-1bp-bos-ma uptime is 1 year, 9 weeks, 2 days, 18 hours, 56 minutes
> System returned to ROM by power-on
> System restarted at 00:45:13 EDT Sat Jul 15 2006
> System image file is "slot0:c7200-ik91s-mz.122-25.S7.bin"
>
> Thanks in advance.
> -- 
> ------------------
> Chris Hale
> chale99 at gmail.com
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--
Alex Balashov
Evariste Systems
Web    : http://www.evaristesys.com/
Tel    : +1-678-954-0670
Direct : +1-678-954-0671