[c-nsp] MLPPP/T1 problems

Tue Sep 18 20:37:38 EDT 2007

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