VWIC-2MFT-T1 Problems

[bret]

Ok, so I have the VWIC-2MFT-T1 installed in a router with 2 data T-1s no voice - kind of a waste I know. The one port is taking incrementing input errors - while the other one is working without problem. I have replaced the cable. I have contacted the provider who says they don't see a problem - go figure. My next alternative is to swap cables and see if the errors follow. But I was curious about other alternatives.

I know on a WIC-1DSU-T1-V2 you can issue a clear service-module serial 0/2/0 and this basically resets the card. I actually had a case where I had a T-1 down on the WIC-1DSU-T1-V2 and it was throwing a %SERVICE_MODULE-4-WICNOTREADY: with traceback errors and was in a down/down state. By issuing the clear service-module serial 0/2/0 basically rebooted the card and brought me up/up and the T-1 was working again.

Does anyone know if such a command exist for the VWIC-2MFT-T1 to reset the port? I am curious to hear your thoughts.

Thanks,

Bret

[Juan Perez]

Hi Bret,

There is a similar command for VWICs but I would not recommend it based on the problem description, we are dealing with physical errors here, microcode reload and clear service-module are used when you want to re-set internal card's chipset (stuck processes, etc). Can you post the show run and show controller t1 outputs?

Regards.

[bret]

Juan,

I hear ya. My only thought was maybe resetting the port, or as you put it "re-set internal card's chipset (stuck processes, etc)" would rule out the port and possibly fix my problem.

interface Serial0/0/0:0

description Connection to

no ip address

encapsulation ppp

ppp chap hostname

ppp multilink

ppp multilink group 1

!

interface Serial0/0/1:0

description Connection to

no ip address

encapsulation ppp

ppp chap hostname

ppp multilink

ppp multilink group 1

T1 0/0/0 is up.

  Applique type is Channelized T1

  Cablelength is long gain36 0db

  No alarms detected.

  alarm-trigger is not set

  Soaking time: 3, Clearance time: 10

  AIS State:Clear  LOS State:Clear  LOF State:Clear

  Version info Firmware: 20090113, FPGA: 20, spm_count = 0

  Framing is ESF, Line Code is B8ZS, Clock Source is Line.

  CRC Threshold is 320. Reported from firmware  is 320.

  Data in current interval (184 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 92 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, 0 Unavail Secs

T1 0/0/1 is up.

  Applique type is Channelized T1

  Cablelength is long gain36 0db

  No alarms detected.

  alarm-trigger is not set

  Soaking time: 3, Clearance time: 10

  AIS State:Clear  LOS State:Clear  LOF State:Clear

  Version info Firmware: 20090113, FPGA: 20, spm_count = 0

  Framing is ESF, Line Code is B8ZS, Clock Source is Line.

  CRC Threshold is 320. Reported from firmware  is 320.

  Data in current interval (179 seconds elapsed):

     0 Line Code Violations, 0 Path Code Violations

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

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

  Total Data (last 82 15 minute intervals):

     0 Line Code Violations, 0 Path Code Violations,

     6813 Slip Secs, 0 Fr Loss Secs, 0 Line Err Secs, 0 Degraded Mins,

     6813 Errored Secs, 0 Bursty Err Secs, 0 Severely Err Secs, 0 Unavail Secs

[Juan Perez]

Hi Bret,

Thanks for the info. I think we are dealing with a clocking issue (limitation) here. Are these T1s going to a remote router or to an MPLS cloud (MLPPP terminted by PE router at TELCO cloud). Do you know who is providing clocking signal?

Here is the limitation I am referring to:

"Note:

The 2-port E1 Multiflex Trunk VWICs has only one shared clocking             domain between the two E1 controllers. So, if both E1 controllers are             configured to derive clocking from the line, the clock references received must             be synchronous. Otherwise, timing slips will occur on at least one of the             controllers. If the clocking sources are pleisochronous and one controller is             configured for "clock source line primary" and the other for "clock source             line", it is likely the second controller will exhibit controlled slips in the             output of the "show controllers E1" command. This behaviour is a hardware             limitation of the 2-port E1 Multiflex Trunk VWIC product and is by design.             However, independent clocking sources can be supported on the 2-port T1/E1             VWIC2 product when both controllers are used for data-only purposes."

http://www.cisco.com/en/US/products/hw/routers/ps274/products_tech_note09186a00800b6e0f.shtml

This basically means that if incoming clocking signal (when deriving clocking from the line on both ports="clock source line") is not synch then slips are expected on the second port of the card, the reason is because this card has a single clocking oscillator.

If you have control of the remote router then we can create/do a workaround by adjusting clock settings.

Regards.

[bret]

I think this shows we are taking clocking from the telco. I am very new to the VWICs and appreciate your help. So is the problem fixed by manipulating the priority, changing the clocking sync somehow. Hopefully, this can be done with out other hardware.

  Network Clock Configuration
  ---------------------------
  Priority      Clock Source    Clock State     Clock Type

    10          Backplane       GOOD            PLL        

  Current Primary Clock Source
  ---------------------------
  Priority      Clock Source    Clock State     Clock Type

    10          Backplane       GOOD            PLL

[Juan Perez]

Hi Bret,

This can be "solved" by playing with local and remote clocking settings, the limitation here is if you have access/control of the remote device. Here is what should be done:

T1 0/0/0--clock source line primary-----------------------------clock source internal---Remote (T1port/Router connected to T10/0/0)

T1 0/0/1--clock source internal-----------------------------------clock source line----Remote (T1port/Router connected to T10/0/1)

This will create a "looped time" circuit, basically local T1 port will derive clocking from line (clock signal being sent by remote T1 port/Router connected to local T1 0/0/0) and pass it to local T1 0/0/1 which will send that incoming clocking signal out towards remote end (clocking received by remote T1 port/Router connected to local T1 0/0/).

I hope this helps!