[cisco-voip] Question about T1 clocking

[Justin Steinberg]

not necessarily.  like you mention if both vwics use the onboard PVDMs, then
they will both participate in the same clocking domain which means there is
potential for slip.  To get two clocking domains, you would have to add
something like a NM-HDV with its own DSPs to create a second clocking
domain.
Of course you could just order the T1 and try the open slot in the existing
VWIC, you might get lucky and find that both are on the same clock.
 However, if you see slips, you'll probably need to order a NM.

Unless something has changed with the new VWIC3s ...?.?.?

On Wed, Feb 4, 2009 at 2:18 PM, Ed Leatherman <ealeatherman at gmail.com>wrote:

> My main concern is since both these are voice connections and they will be
> faxing over both links.. clock slips seem to cause trouble in that regard.
> Would adding the second VWIC eliminate the slip problem?
>
> On Wed, Feb 4, 2009 at 9:52 AM, Estes, Timothy <TimothyEstes at spherion.com>wrote:
>
>>  I have this running on about 90 28XX routers in the field. Sprint MPLS
>> circuits on the data side and Verizon or AT&T PRIs. You have to set network
>> clock select to the PRI for it to come up, therefore the data circuit slips.
>> Out of the 90 sites, only 2 have required new VWICs because of errors. The
>> rest tolerate the slips. I see as low as 15 and as many as 90 slip seconds
>> on the data circuits. 40 or 50 seems to be the limit for me, your mileage
>> may vary.
>>
>>
>>
>>
>>
>>
>>
>> Timothy Estes
>>
>> Data Network Operations Engineer
>>
>> ACS / Spherion
>>
>> Ft. Lauderdale FL
>>
>
>
>
> --
> Ed Leatherman
> Assistant Director, Voice Services
> West Virginia University
> Telecommunications and Network Operations
>
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>
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