[cisco-voip] Clocking/slips issue with Nortel

[Andrius Kislas]

Nick, thanks for ideas. I will discuss them with Nortel guys.

Regards,
Andrius

Nick Matthews wrote:
> Hi Andrius,
> 
> In this scenario it would be more practical for Nortel to provide the
> clock since they are receiving it on the PSTN.  For Cisco routers at
> least, each set of DSPs can only keep track of 1 clock.  Unless you
> have an HDV plus DSPs on the motherboard, you have one set of DSPs,
> and Nortel is likely in the same scenario.  The way you've described
> it they need to keep up with your internal clock plus the PSTN clock.
> 
> Have them set themselves as network, and set clock source line.  I
> don't believe the network clock select commands will be properly
> applied when you're doing internal clock anyway, but you will need it
> when you are in clock source line.
> 
> Other than that, try different cables/hardware, or use nortel commands
> to reduce the dB if they exist.
> 
> -nick
> 
> On Tue, Dec 15, 2009 at 9:01 PM, Andrius Kislas <andrius-conf at kislas.lt> wrote:
>> Hi,
>>
>> I have a clocking / slips problem connecting Cisco 3845 to Nortel
>> CS1000M r4.5. The scenario is following:
>>
>> Nortel is already connected to PSTN and is getting clock from network
>> (PSTN). Now I connect C3845 to Nortel using QSIG protocol and NM modules
>> NM-HDV2-2T1/E1. They ask me to be a network side and to provide
>> clocking. I do the following:
>>
>> network-clock-participate slot 1
>> network-clock-participate slot 2
>>
>> controller E1 1/0
>>  clock source internal
>>  pri-group timeslots 1-31
>> !
>> controller E1 1/1
>>  clock source internal
>>  pri-group timeslots 1-31
>> !
>> controller E1 2/0
>>  clock source internal
>>  pri-group timeslots 1-31
>>
>>
>> L2 us up, L3 is up (calls initiate) but unfortunately on both sides we
>> see slips. I don't get any clocking from line, so I cannot use
>> "network-clock-select". Here is one "show":
>> Router#sh network-clocks
>>  Network Clock Configuration
>>  ---------------------------
>>  Priority      Clock Source    Clock State     Clock Type
>>    11          Backplane       GOOD            PLL
>>
>>  Current Primary Clock Source
>>  ---------------------------
>>  Priority      Clock Source    Clock State     Clock Type
>>    11          Backplane       GOOD            PLL
>>
>> I have also tried to "no network-clock-participate slot 1 (and 2)" but
>> still the same - slips. Is there anything else I could do to correct
>> configuration and provide a proper clocking?
>> Am I right that best practice would be if Nortel would be a clocking
>> source as it gets clocking from PSTN?
>>
>> Thanks for any comments,
>> Andrius
>>
>>
>>
>>
>>
>>
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>