2811 serial port down

[scdladmin]

Upgrading a remote site with a new 2811 router, IOS version 12.4(3c) A WIC-1DSU-T1-V2 module is installed. On startup, module is recognized and passes diag tests.

T1 line uses HDLC encap; ESF framing; B8ZS line code; clock source is on the line.

Since these are all defaults in IOS config, the only thing I have added is the IP address for the Serial 0/0/0 interface and issued the 'no shutdown' command.

However, when moving the cable from the old external CSU/DSU to the WIC module, I do not get carrier. The int display shows Serial0/0/0 is down, protocol down and is not in loopback.

Telco Smartjack LEDs are same as when cable is connected to old, external DSU.

I'm out of ideas as to what else to check or look for.

Any ideas?

TIA

[wochanda]

The WIC-1DSU-T1-V2 has been found to be more sensitive to link misconfigurations than other manufacturers CSU/DSU's, and even the 1st generation WIC-1DSU-T1.

Make sure the hardware is good with a hard loopback test. To do this, either find a loopback plug with Pin 1 looped to 4, Pin 2 to 5. If you dont have one of these, cut a known good ethernet cable in half, strip these 4 pins, and tie the proper ones together. If plugging this loopback into the link comes up, you're going to want to pursue a line issue with the telco.

In 90% of cases i've seen with this issue, once the telco modifies their LBO on the smartjack, the line comes up. Call your telco and tell them to try lowering the LBO to -7.5dB.

Can you paste in the output of 'show service-module serial0/0/0'?

[scdladmin]

Thanks for the reply.

I was at the remote site today and copied the service-module output, which is below. Note that the alarm messages are due to the fact that the T1 line is not connected to this unit at the time. The building was open for business and the line was connected to the older equipment.

Rtr_SNO#sh service-module

Module type is T1/fractional

Hardware revision is 1.0, Software revision is 20060106,

Image checksum is 0x3EC4CA, Protocol revision is 0.1

Transmitter is sending remote alarm.

Receiver has loss of signal, loss of frame,

Framing is ESF, Line Code is B8ZS, Current clock source is line,

Fraction has 24 timeslots (64 Kbits/sec each), Net bandwidth is 1536 Kbits/sec.

Last module self-test (done at startup): Passed

Last clearing of alarm counters 1d23h

loss of signal : 1, current duration 1d23h

loss of frame : 1, current duration 1d23h

AIS alarm : 0,

Remote alarm : 0,

Module access errors : 0,

Total Data (last 96 15 minute intervals):

0 Line Code Violations, 0 Path Code Violations

0 Slip Secs, 86400 Fr Loss Secs, 0 Line Err Secs, 0 Degraded Mins

0 Errored Secs, 0 Bursty Err Secs, 2147483647 Severely Err Secs, 86399 Unavail Secs

Data in current interval (166 seconds elapsed):

0 Line Code Violations, 0 Path Code Violations

0 Slip Secs, 166 Fr Loss Secs, 0 Line Err Secs, 0 Degraded Mins

0 Errored Secs, 0 Bursty Err Secs, 0 Severely Err Secs, 166 Unavail Secs

[wochanda]

Yeah...the 'show service-module' doesn't really do us a whole lot of good. What we're going to be looking for are 'Line code violations' and 'path code violations' incrementing when we're plugged into the link.

If these are incrementing, do the hard loop I mentioned before. If the hard loop is clean, you're going to have to fight with the telco about their build out settings on the smartjack.

If you have a Cisco contract, you may consider opening a TAC case. Sometimes telcos wont make any changes until you have some of our muscle behind you :).

[scdladmin]

Used an old break-out-box and connector and created a loopback with pins 1-4, 2-5. However, hooking this up to the line in Serial0 didn't bring the line up.

Hooked the router up to the circuit on Sunday and ran the sh int and sh service-module commands. Output is below. Encapsulation, Framing, Linecode and clock source settings all match those of the old router's config which does work with the external CSU/DSU.

If this is a hardware problem, I guess what isn't making sense to me is that the WIC module is recognized by the router and it passes hardware diag tests.

We don't have a Cisco service contract, which is why I've utilized the forums up to now.

Rtr_SNO#sh int s0/0/0

Serial0/0/0 is down, line protocol is down

Hardware is GT96K with integrated T1 CSU/DSU

Internet address is 192.168.142.2/30

MTU 1500 bytes, BW 1544 Kbit, DLY 20000 usec,

reliability 255/255, txload 1/255, rxload 1/255

Encapsulation HDLC, loopback not set

Keepalive set (10 sec)

Last input never, output never, output hang never

Last clearing of "show interface" counters 1d15h

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 0/0/256 (active/max active/max total)

Reserved Conversations 0/0 (allocated/max allocated)

Available Bandwidth 1158 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, 0 giants, 0 throttles

0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort

0 packets output, 0 bytes, 0 underruns

0 output errors, 0 collisions, 0 interface resets

0 output buffer failures, 0 output buffers swapped out

0 carrier transitions

DCD=down DSR=up DTR=up RTS=up CTS=down

Rtr_SNO#show service-module

Module type is T1/fractional

Hardware revision is 1.0, Software revision is 20060106,

Image checksum is 0x3EC4CA, Protocol revision is 0.1

Transmitter is sending remote alarm.

Receiver has loss of signal, loss of frame,

Framing is ESF, Line Code is B8ZS, Current clock source is line,

Fraction has 24 timeslots (64 Kbits/sec each), Net bandwidth is 1536 Kbits/sec.

Last module self-test (done at startup): Passed

Last clearing of alarm counters 1d15h

loss of signal : 1, current duration 1d15h

loss of frame : 1, current duration 1d15h

AIS alarm : 0,

Remote alarm : 0,

Module access errors : 0,

Total Data (last 96 15 minute intervals):

0 Line Code Violations, 0 Path Code Violations

0 Slip Secs, 86400 Fr Loss Secs, 0 Line Err Secs, 0 Degraded Mins

0 Errored Secs, 0 Bursty Err Secs, 0 Severely Err Secs, 86400 Unavail Secs

Data in current interval (580 seconds elapsed):

65328 Line Code Violations, 1023 Path Code Violations

0 Slip Secs, 373 Fr Loss Secs, 208 Line Err Secs, 0 Degraded Mins

0 Errored Secs, 0 Bursty Err Secs, 0 Severely Err Secs, 580 Unavail Secs

[scottmac]

This is likely to be a long shot, but how long is the cabling from the smartjack, and what kind of cabling is it?

The spec for DS1/T1 is actually "Premises Cable" which is individual shielded pair inside a shielded jacket (versus Category{anything}).

Many people use UTP/Cat5,5e,6, and its generally OK for shorter runs. If your routers are some distance from the smartjack, try moving the new one closer to the smartjack and using a shorter cable (especially if it's UTP).

Good Luck

Scott

[scdladmin]

Looks like this isn't going to work. Either the module is bad, the router is bad, or the module isn't the right one for this model router.

I want to order another module for this unit, but am wondering if the WIC-1DSU-T!-V2 is the right module.

Online documentation for this module does not say it works with 2800 series routers, but we had originally verified with Cisco sales that it would work in the 2811 prior to ordering.

What is the correct module for a T1 CSU/DSU in the 2811 router?

The VWIC2-1MFT-T1/E1?

Thanks.

[wochanda]

You've got the right module. The issue is most likely a line issue from the telco. Like I said earlier, these DSU-V2's are much more sensitive to misconfigured lines than other cards, which is why the T1 is coming up on the other CSU/DSU.

A VWIC2-1MFT-T1/E1 shares many components with the WIC-1DSU-T1-V2, so there is a very good chance you'll see the problem there too.

It could also be a problem with this particular WIC, so you may consider throwing another one at the problem.

If another WIC doesn't work, you're options are:

1. Get telco to fix line (modify line build out)

2. Move to a VWIC-1MFT-T1 (old chipset, less sensitive)

[Steven Landon]

If you are unable to loopback the card, i would avoid putting pressure on the Telco to rebuild the line. If the card won't loopback, it won't connect to a good T1.

Steve