3825 PRIs to different telco equip clocking issue (slip secs)

[cooperben]

We have a 3825ISR with (2) 2-port WICs (V2).  Because of internal company/subsidiaries, WIC0 has 2 full PRIs outbound to our carrier's 3945 (dial-peer 9.T), and WIC1 has 1 full PRI outbound to separate carrier 2921 (dial-peer 8.T, with second WIC1 port shut).  The carrier's equipment is located in our datacenter.

My problem is that I am seeing lots of slip secs on WIC1's PRI.  After researching, I am sure the clocking problems are because there are two separate telco routers connected via PRI to our 3825.  Is there any way to tell my 3825 to separate the two?  Or must I request the carrier gets their clocking from us on the problem PRI?

All the T1 ports are set to clock source line and linecode and framing are not an issue.  I have seen a clock-source command 'independent', but am not sure how to apply it, or if it is even supported in Gen2 hardware like the 3825.  I have swapped out the cable with known good replacements, with no improvement.  Relevant config and sh controller output below:

IOS 15.1(4)M8 ADVIPSERVICES

card type t1 0 0
card type t1 0 1

network-clock-participate wic 0
network-clock-participate wic 1
network-clock-select 1 T1 0/0/0
network-clock-select 2 T1 0/0/1
network-clock-select 3 T1 0/1/0
network-clock-select 4 T1 0/1/1

controller T1 0/0/0
 cablelength short 110
 pri-group timeslots 1-24
 description PRI 1
!
controller T1 0/0/1
 cablelength short 110
 pri-group timeslots 1-24
 description PRI 2
!
controller T1 0/1/0
 cablelength short 110
 pri-group timeslots 1-24
 description PRI 3
!
controller T1 0/1/1
 shutdown

sh controller t1 0/1/0

T1 0/1/0 is up.
  Applique type is Channelized T1
  Cablelength is short 110
  Description: PRI 3
  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: 20100222, FPGA: 13, 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 (144 seconds elapsed):
     0 Line Code Violations, 0 Path Code Violations
     43 Slip Secs, 0 Fr Loss Secs, 0 Line Err Secs, 0 Degraded Mins
     43 Errored Secs, 0 Bursty Err Secs, 0 Severely Err Secs, 0 Unavail Secs
  Data in Interval 1:
     0 Line Code Violations, 0 Path Code Violations
     272 Slip Secs, 0 Fr Loss Secs, 0 Line Err Secs, 0 Degraded Mins
     272 Errored Secs, 0 Bursty Err Secs, 0 Severely Err Secs, 0 Unavail Secs
  Data in Interval 2:
     0 Line Code Violations, 0 Path Code Violations
     273 Slip Secs, 0 Fr Loss Secs, 0 Line Err Secs, 0 Degraded Mins
     273 Errored Secs, 0 Bursty Err Secs, 0 Severely Err Secs, 0 Unavail Secs
  Data in Interval 3:
     0 Line Code Violations, 0 Path Code Violations
     271 Slip Secs, 0 Fr Loss Secs, 0 Line Err Secs, 0 Degraded Mins
     271 Errored Secs, 0 Bursty Err Secs, 0 Severely Err Secs, 0 Unavail Secs
  Total Data (last 3 15 minute intervals):
     0 Line Code Violations, 0 Path Code Violations,
     816 Slip Secs, 0 Fr Loss Secs, 0 Line Err Secs, 0 Degraded Mins,
     816 Errored Secs, 0 Bursty Err Secs, 0 Severely Err Secs, 0 Unavail Secs

sh network

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

     1          T1 0/0/0        GOOD            T1
     2          T1 0/0/1        GOOD            T1
     3          T1 0/1/0        GOOD            T1
     4          T1 0/1/1        SHUTDOWN        T1
    11          Backplane       GOOD            PLL

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

     1          T1 0/0/0        GOOD            T1

[Brian Meade · Accepted solution]

It looks like independent doesn't work with voice:

http://www.cisco.com/c/en/us/td/docs/ios/12_2/12_2z/12_2zj/feature/guide/gthwecan.html

"Note When independent clocking is configured, the controller will support only one channel group and no voice applications"

It looks like you're pretty limited here unless you can get one carrier to accept you as the clocking source which I doubt they will be okay with.  You could try changing the priorities around to have another PRI act as the network clock source and see if that helps at all.

[cooperben]

Brian, thanks for the reply.

Is it possible to have one WIC/2 PRIs using clock-source line and the other WIC/PRI using clock source internal?  If I am able to convince the carrier to accept us as clock source, that is.  I just want to see if it is even possible with our hardware before fighting that battle...

[Brian Meade]

It should be possible under the controller configuration.

[cooperben]

Brian, thanks for your replies.  I just have one more question...

Before setting my clock source to internal on the 0/1/0 interface, should I run the command no network-clock-select 3 T1 0/1/0 first?  All assuming I can get the telco to comply, of course.

Example:

no network-clock-select 3 T1 0/1/0

controller t1 0/1/0

clock source internal

I'm just not sure how network-clock-select relates to being a clock source, as opposed to the usual clock source line.

[Brian Meade]

That's fine buy may not be necessary since 0/0/0 is currently the network clock source since it has a priority of 1.