[cisco-voip] Avoid Clocking issues with PRI

Thu Oct 18 21:22:24 EDT 2012

Here's the response I recieved from TAC:

Since you are going to have 2 different clocking domains, you just
need to configure the VWIC3-4MFT-T1/E1 to participate. This is an
example:

 network-clock-participate  wic 1

network-clock-select  1  t1 /0/1/0

 where 0/1/0 is the VWIC3-4MFT-T1/E1. You do not need configure
clocking for the NM-HDV2-1T1/E1 because it is going to be in a
different clocking domain.

On Wed, Oct 17, 2012 at 12:46 PM, Nate VanMaren
<VanMarenNP at ldschurch.org> wrote:
> But remember the carriers have to connect to each other, and so usually
> their clocks are in sync already.
>
>
>
> From: Heim, Dennis [mailto:Dennis.Heim at wwt.com]
> Sent: Wednesday, October 17, 2012 10:38 AM
> To: Nate VanMaren; Ted Nugent
> Cc: cisco-voip at puck.nether.net
>
>
> Subject: RE: [cisco-voip] Avoid Clocking issues with PRI
>
>
>
> Many times you can have a different carrier by name but it is still going
> into either the same CO switch, or a switch that is using the same stratum
> clock. It is one of those things you only find out the hard way which is
> when you are trying to bring up a circuit late at night.
>
>
>
> Dennis Heim | Sr. UC Engineer
>
> World Wide Technology | 314.212.1814 | dennis.heim at wwt.com
>
> “Creating Impact, Ignition & Scalability”
>
>
>
> From: Nate VanMaren [mailto:VanMarenNP at ldschurch.org]
> Sent: Wednesday, October 17, 2012 12:03 PM
> To: Ted Nugent; Heim, Dennis
> Cc: cisco-voip at puck.nether.net
> Subject: RE: [cisco-voip] Avoid Clocking issues with PRI
>
>
>
> I have a lot (5-9 or so) of carriers coming into our main site.  I haven’t
> had any clocking issues, except when we were first integrating with our PBX.
>
>
>
> My plan was to move offending carriers to a different gateway, but I just
> haven’t had the need.  Most of the circuits come in on a DS3 that we break
> out to T1s, but I don’t think that has a major impact.
>
>
>
> So knowing the limitations of the clocking domains is important, but I would
> only deal with it once you have confirmed there really is a difference
> between the clocks on the different carriers.
>
>
>
> -Nate
>
>
>
> From: cisco-voip-bounces at puck.nether.net
> [mailto:cisco-voip-bounces at puck.nether.net] On Behalf Of Ted Nugent
> Sent: Tuesday, October 16, 2012 6:41 PM
> To: Heim, Dennis
> Cc: cisco-voip at puck.nether.net
> Subject: Re: [cisco-voip] Avoid Clocking issues with PRI
>
>
>
> Oh I absolutely agree and that's how it's always been however I thought I
> had heard that was one of the "great things" announced about the ISR2 and
> the newer VWIC3s but it's very possible I was not paying attention closely
> enough. I'll find the slides tomorrow and confirm but it's probably just
> what was listed in that doc posted above about having data and voice clocked
> independently off the same card, that would make a lot more sense since I
> don't see any new commands to "partition" the DSP or anything of that
> nature.
>
> On Tue, Oct 16, 2012 at 7:30 PM, Heim, Dennis <Dennis.Heim at wwt.com> wrote:
>
> The problem like Jason said with voice is those DSPs. The NM module works
> because it has its own dedicated PVDMs.
>
>
>
> Dennis Heim
>
> Sr. UC Engineer
>
> World Wide Technology
>
> Office: 314.212.1814
>
> Email: dennis.heim at wwt.com
>
> www.wwt.com
>
>
>
> From: cisco-voip-bounces at puck.nether.net
> [mailto:cisco-voip-bounces at puck.nether.net] On Behalf Of Jason Aarons (AM)
> Sent: Tuesday, October 16, 2012 7:26 PM
> To: Steven Sarte; Ted Nugent
>
>
> Cc: cisco-voip at puck.nether.net
> Subject: Re: [cisco-voip] Avoid Clocking issues with PRI
>
>
>
> I suspect you still can’t have 2 voice PRIs with different clocks.  How
> would your carve up the mother board/backplane DSP resources to clock to
> each port?    I’d still go with a separate router for voice PRIs to separate
> carriers.
>
>
>
> From: Steven Sarte [mailto:steven.sarte at gmail.com]
> Sent: Tuesday, October 16, 2012 7:23 PM
> To: Ted Nugent
> Cc: Jason Aarons (AM); cisco-voip at puck.nether.net
> Subject: Re: [cisco-voip] Avoid Clocking issues with PRI
>
>
>
> With the new VWIC3 you can have independent clocking when you have a voice
> PRI and data T1 on a 2 port card.
>
>
>
> As for NM I'm reading that it's a separate clocking domain from the VWIC
> cards.
>
>
> Sent from my iPhone
>
>
> On Oct 16, 2012, at 7:08 PM, Ted Nugent <tednugent73 at gmail.com> wrote:
>
> Hmm, does this imply that you can have 2 seperate VWIC3s in the same ISR2
> chassis supporting thier own voice clocking domains or are we still under
> the same restrictions where the ISR2 only supports a single clocking domain
> for voice? Thought that was what I heard but it's possible this is what I'm
> remembering.
>
>
>
> http://www.cisco.com/en/US/prod/collateral/routers/ps5855/prod_qas0900aecd8028d2e5_ps10537_Products_Q_and_A_Item.html
>
>
>
> Q. How do the Cisco VWIC3 cards differ from the VWIC2 cards?
>
> A. The Cisco VWIC3 cards are supported only on the Cisco Integrated Services
> Router (ISR) 1900, 2900, 3900 and 3900E series platforms. The VWIC3 cards
> add enhancements to the previous generation VWIC2 cards, including:
>
> Enhanced clocking capabilities: The Cisco VWIC3 cards can enable each port
> to be clocked from an independent clock source for data applications. Data
> ports can also be clocked independent of voice ports. All voice ports on the
> card much use the same clock source.
>
> Q. Can the 2- and 4-port VWIC3 cards support different clocking domains?
>
> A. When the 2- or 4-port VWIC3 is used in data only, non-ATM applications,
> each port can connect to a different clocking domain, for example, when two
> different T1/E1 carriers are used. When the VWIC3 is used for voice
> applications, all voice T1/E1s have to be synchronized to a single clock
> source and any difference in clocks risk clock slips or interface flaps.
> When the VWIC3 is used for mixed data and voice applications, each data port
> can use an independent clock, and the voice ports can use a clock source
> independent from the data ports.
>
>
>
>
>
>
>
>
>
> On Tue, Oct 16, 2012 at 5:48 PM, Ted Nugent <tednugent73 at gmail.com> wrote:
>
> I thought for sure I heard at a partners summit or networkers that
> ISR2/VWIC3 no longer fall under those restrictions. Time to start scouring
> my slides...
>
>
>
> On Tue, Oct 16, 2012 at 5:44 PM, Steven Sarte <steven.sarte at gmail.com>
> wrote:
>
> Take a look at this white paper:
> http://www.cisco.com/en/US/prod/collateral/routers/ps5854/prod_white_paper0900aecd805b9915.html
>
> Under the section titled: Clocking and Timing Options
>
> Thanks,
> Steven
>
>
> On Tue, Oct 16, 2012 at 5:32 PM, Jason Aarons (AM)
> <jason.aarons at dimensiondata.com> wrote:
>> This doesn’t work when you have PRIs from different providers.
>>
>>
>>
>> The original VWIC2 has a single PLL and backplane could not clock from
>> multiple sources.
>>
>>
>>
>> From: cisco-voip-bounces at puck.nether.net
>> [mailto:cisco-voip-bounces at puck.nether.net] On Behalf Of Roger Wiklund
>> Sent: Tuesday, October 16, 2012 4:40 PM
>> To: Steven Sarte
>> Cc: cisco-voip at puck.nether.net
>> Subject: Re: [cisco-voip] Avoid Clocking issues with PRI
>>
>>
>>
>>
>>
>> Dunno about the NM, I just use network-clock-select 1 e1 x/y/z and
>> ensure you have clock source line. That's enough to keep it slips
>> free.
>>
>> Regards
>> Roger
>>
>> On Tue, Oct 16, 2012 at 10:28 PM, Steven Sarte <steven.sarte at gmail.com>
>> wrote:
>>> I have two SP's for my PRI's on a 2921 currenty using a
>>> VWIC3-4MFT-T1/E1. I opened a Cisco Partner case and they told me you
>>> can avoid timing slips by using a Network Module PRI, like a
>>> NM-HDV2-T1/E1 and a VWIC3-4MFT-T1/E1 in the WIC slots.
>>>
>>> Has anyone configured this before? What would the clocking
>>> configuration look like. I did open a Cisco TAC case but he was not
>>> very helpful in his first reply.
>>>
>>> Thanks in advance,
>>> Steven
>>> _______________________________________________
>>> cisco-voip mailing list
>>> cisco-voip at puck.nether.net
>>> https://puck.nether.net/mailman/listinfo/cisco-voip
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>>
>>
>> itevomcid
>
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