Help with PPP T1 troubleshooting

[kt]

I have been playing around with this for a week now and AT&T is telling me there is nothing wrong with the T1 circuit. But I can't get the two routers to connect. Here's the setup and configuration:

Site A: Cisco 2821
!
controller T1 0/1/0
framing esf
linecode b8zs
channel-group 0 timeslots 1-24
!
!
interface Multilink1
ip address 192.168.0.103 255.255.255.0
ip tcp header-compression iphc-format
no cdp enable
ppp multilink
ppp multilink fragment delay 10
ppp multlink interleave
ppp multilink group 1
ppp service-policy output voice_policy
ip rtp header-compression iphc-format
!
!
interface Serial0/1/0:0
bandwidth 1540
no ip address
encapsulation ppp
fair-queue
ppp multilink
ppp multilink group 1
!

Site B: Cisco 2610XM
!
controller T1 0/0
framing esf
linecode b8zs
channel-group 0 timeslots 1-24
!
!
interface Multilink1
ip address 192.168.0.102 255.255.255.0
ip tcp header-compression iphc-format
no cdp enable
ppp multilink
ppp multilink fragment delay 10
ppp multlink interleave
ppp multilink group 1
ppp service-policy output voice_policy
ip rtp header-compression iphc-format
!
!
interface Serial0/0:0
bandwidth 1540
no ip address
encapsulation ppp
fair-queue
ppp multilink
ppp multilink group 1
!

The output for 'show interface' on Serial0/1/0:0 is:
Serial0/1/0:0 is up, line protocol is down
Hardware is GT96K Serial
MTU 1500 bytes, BW 1540 Kbit, DLY 20000 usec,
reliability 128/255, txload 1/255, rxload 1/255
Encapsulation PPP, LCP REQsent, multilink Closed, loopback not set
Keepalive set (10 sec)
Last input 1d18h, output 00:00:01, output hang never
Last clearing of "show interface" counters 1w0d
Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
Queueing strategy: weighted fair
Output queue: 0/1000/64/0 (size/max total/threshold/drops)
Conversations 0/1/256 (active/max active/max total)
Reserved Conversations 0/0 (allocated/max allocated)
Available Bandwidth 1155 kilobits/sec
5 minute input rate 0 bits/sec, 0 packets/sec
5 minute output rate 0 bits/sec, 0 packets/sec
2680 packets input, 61640 bytes, 0 no buffer
Received 0 broadcasts, 0 runts, 0 giants, 0 throttles
1611885 input errors, 1611881 CRC, 787474 frame, 437505 overrun, 0 ignored, 1181161 abort
137393 packets output, 4104436 bytes, 0 underruns
0 output errors, 0 collisions, 13612 interface resets
0 output buffer failures, 0 output buffers swapped out
14 carrier transitions
Timeslot(s) Used:1-24, SCC: 0, Transmitter delay is 0 flags

The output for 'show interface' on Serial0/0:0 is:
Serial0/0:0 is up, line protocol is down
Hardware is PowerQUICC Serial
MTU 1500 bytes, BW 1540 Kbit, DLY 20000 usec,
reliability 184/255, txload 1/255, rxload 1/255
Encapsulation PPP, LCP Listen, multilink Closed, loopback not set
Keepalive set (10 sec)
Last input never, output 00:00:28, output hang never
Last clearing of "show interface" counters 1d16h
Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
Queueing strategy: weighted fair
Output queue: 0/1000/64/0 (size/max total/threshold/drops)
Conversations 0/1/256 (active/max active/max total)
Reserved Conversations 0/0 (allocated/max allocated)
Available Bandwidth 1155 kilobits/sec
5 minute input rate 0 bits/sec, 0 packets/sec
5 minute output rate 0 bits/sec, 0 packets/sec
0 packets input, 0 bytes, 0 no buffer
Received 0 broadcasts, 0 runts, 8952 giants, 0 throttles
11807 input errors, 667 CRC, 4867 frame, 0 overrun, 0 ignored, 6273 abort
29180 packets output, 875400 bytes, 0 underruns
0 output errors, 0 collisions, 7819 interface resets
0 output buffer failures, 0 output buffers swapped out
3 carrier transitions
Timeslot(s) Used:1-24, SCC: 0, Transmitter delay is 0 flags

 

[bill00009912]

Not sure why you multilink configured when you only have a single link unless you did show both.

You can start with debug ppp negotiation and debug ppp multilink events and see if you see anything intersting. There are many options on the debug ppp command just keep turning them on until you see why ppp will not come up.

If it is not obvious I would post this question along with those debug results to the cisco forums at forums.cisco.com. That forum has many CCIE's who answer questions like this all the time.

 

[ITJunkie]

Just at a quick glance, shouldn't you're "bandwidth" setting be 1544 not 1540?

 

[kt]

We will be adding a second T1 line to the bundle, so might as well have it configured now. As for the bandwidth setting, I don't think that is the problem. Bandwidth setting does not affect the actual physical interface, it's only a routing parameter.

Thanks for the info on the Cisco forums..

 

[bill00009912]

Originally posted by: ITJunkie
Just at a quick glance, shouldn't you're "bandwidth" setting be 1544 not 1540?

Bandwidth has no effect on ppp or the real physical speed of the interface. It is only used by routing protocols to caclulate metrics and for the QoS options to calculate some ot thier settings. It is nice to have correct but as long as you are consitant it should not cause a issue to not have them be accurate