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Community Member

Help! I cannot get my Point-to-Point T1 lines working

I have 3 new point-to-point T1 lines running between my main datacenter and my DR location. I am trying to terminate them on Cisco 3600 routers with WIC-1DSU-T1 cards and bond them together with PPP multilink. I have configured both routers and installed and connected the WICs, but I am getting alarm lights on the WICs. The telco provider is saying that everything looks good to their equipment and it is something on my end. Can anyone help me troubleshoot my equipment and try to identify where I've gone wrong?

Here is an excerpt from one of the WIC-T1 cards in one of the routers if this helps get started...

Module type is T1/fractional

Hardware revision is 0.104, Software revision is 0.2,

Image checksum is 0x73D70058, Protocol revision is 0.1

Transmitter is sending remote alarm.

Receiver has loss of frame, AIS alarm,

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 5d08h

loss of signal : 1, last occurred 5d08h

loss of frame : 4, current duration 16:26:30

AIS alarm : 3, current duration 16:26:30

Remote alarm : 7964, last occurred 16:26:52

Module access errors : 0,

Total Data (last 96 15 minute intervals):

0 Line Code Violations, 1020 Path Code Violations

0 Slip Secs, 84560 Fr Loss Secs, 0 Line Err Secs, 0 Degraded Mins

0 Errored Secs, 0 Bursty Err Secs, 0 Severely Err Secs, 84570 Unavail Secs

Data in current interval (835 seconds elapsed):

0 Line Code Violations, 0 Path Code Violations

0 Slip Secs, 835 Fr Loss Secs, 0 Line Err Secs, 0 Degraded Mins

0 Errored Secs, 0 Bursty Err Secs, 0 Severely Err Secs, 835 Unavail Secs

----------------------------------

Serial1/0 is down, line protocol is down

Hardware is QUICC with integrated T1 CSU/DSU

Description: Disaster Recovery point-to-point T1 #1

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

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

Encapsulation PPP, loopback not set

LCP Closed, multilink Closed

Closed: BRIDGECP, IPCP, CCP, CDPCP, LLC2, BACP, IPV6CP

Last input 19:55:42, output 17:12:58, output hang never

Last clearing of "show interface" counters 3d22h

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

40 packets input, 940 bytes, 0 no buffer

Received 0 broadcasts, 0 runts, 24 giants, 0 throttles

195 input errors, 0 CRC, 169 frame, 0 overrun, 0 ignored, 2 abort

26105 packets output, 861085 bytes, 0 underruns

0 output errors, 0 collisions, 19314 interface resets

0 output buffer failures, 0 output buffers swapped out

15934 carrier transitions

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

9 REPLIES
Silver

Re: Help! I cannot get my Point-to-Point T1 lines working

The lines

Transmitter is sending remote alarm.

Receiver has loss of frame, AIS alarm,

tell that this is a carrier problem . find out what they can and can not loop , make them loop up the smart jacks on both ends . If the can not loop the smart jack then is with out a doubt carrier , if they can, find out if there is an extrended demarc , The line may be fine up to where the carrier drops it in to the building but the wiring from the demarc to the router may be bad . If you can physically inspect the smartjack you can look to see if it in alarm .

Hop this helps

Ps make sure they are looking at the correct circuit.

Community Member

Re: Help! I cannot get my Point-to-Point T1 lines working

The carrier is saying that they can loop both smart jacks successfully. The smart jacks at my location are not showing alarm lights, but 2 of the 3 are showing TLOS (__ loss of signal). Also, I just noticed in looking at my Cisco 3662 router that it shows SLOT2, where 2 of the 3 WICs are installed as ready but not active. Is this expected or could there something going on with the module in that slot?

Silver

Re: Help! I cannot get my Point-to-Point T1 lines working

Do you have an extended demarc ? If you do I would this looked at .

Community Member

Re: Help! I cannot get my Point-to-Point T1 lines working

There is one at the other location, but they claim to have tested and re-tested that as well. Is there any kind of test I can run on the router at my location to elminate it as a problem? For instance, can I perform a test of the WICs to try and get them out of the alarm state?

Or perhaps, if the carrier loops the smart jack at the other location (essentially taking the demarc out of the loop), should the WICs in the router at my location come out of the Alarm status?

I'm not very experience in the WAN environment so I apologize if this is a dumb question.

Silver

Re: Help! I cannot get my Point-to-Point T1 lines working

What you can do is have some one at the remote site give you a hard loop on the smartjack , This is done by taking a male rj 45 connector and puting 2 wires from pins 1-4 and pins 2-5 this will loop the circuit back . You should see the router on the other end go up up (looped).

You may also be able to have the carrier give you a loop on the remote smartjack back to your site and see if you see that loop . THis would be easier . If the provider can not do this then you have to use the hard loop option

Bronze

Re: Help! I cannot get my Point-to-Point T1 lines working

I suggest making a RJ48 looping socket and plugging the end of the cable that you connect to the smart jack into it and see if the alarms go away on your WIC. If they do, your cable and WIC are good and you should have your carrier do something about the smart jack. If the alarms do not go away replace the cable.

To make the looping socket, connect pin 1 to pin 4 and pin 2 to pin 5.

Good luck.

Mark

Community Member

Re: Help! I cannot get my Point-to-Point T1 lines working

So I make a cable as described above and plug one end of it into the smart jack and the other end of it into one of my WICs. This should loop between my WIC and the SmartJack and bring that particular interface to an UP/UP status.

Is this correct.

Thanks for all of your assistance on this.

Justin

Silver

Re: Help! I cannot get my Point-to-Point T1 lines working

no you want to do this on the remote smartjack , This is the site with the extended demarc. It would be easier to contact the carrier to have them do this

what this will do is it will prove the entire circuit from the remote demarc all the way to the router at your location . If the line is good you will see your serial interface go

Serialxx is up, line protocol is up(looped)

If this happens then the problem is beyond the demarc at the remote site . most likely wiring .

Community Member

Re: Help! I cannot get my Point-to-Point T1 lines working

OK, in looking further and trying to figure out where the problem might be I have discovered one additional thing on the hardware side. Although all of the WICs are WIC-1DSU-T1 cards, when performing a 'show interface serialx/x' command, some of them say:

Hardware is QUICC with integrated T1 CSU/DSU

and others say:

Hardware is DSCC4 with integrated T1 CSU/DSU

Does anyone know what the difference is between these and/or if this could be causing the communications problems between the routers?

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