E1 PRI Clock Sourcing Question

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Guest

E1 PRI Clock Sourcing Question

Post by Guest » Sat Mar 20, 2010 11:36 pm


Hello, I'm configuring the following scheme: CUCM <mgcp> 2821 <e1-pri> 2821 <fxs> analog phone.Have a question about how to avoid different violations and errors (they are accumulated for now) on E1 controllers.1. The first 2821 router I've configured the following way (among others):- "External clock" in the endpoint configuration in CUCM Administration- "network-clock-participate wic 1"- "show controller e1" tells that 'Clock Source is Line'- ISDN L2 is up, D-channel (CUCM controlled) is up2. The second 2821 router I've configured the following way (among others):- "network-clock-participate wic 1"- "show controller e1" tells that 'Clock Source is Line'- ISDN L2 is up, D-channel is upAs I see, the clock source can be only one.I have no routers except these two.So how can it be possible to regulate the clock between them ?

Guest

Re:E1 PRI Clock Sourcing Question

Post by Guest » Sat Mar 20, 2010 11:53 pm


Hi, on both routers are "network-clock-select 1 E1 1/0".Slips will cease and you will be fine.Hope this helps, please rate post if it does!

Guest

Re:E1 PRI Clock Sourcing Question

Post by Guest » Sun Mar 21, 2010 12:51 am


Paolo,1.As always you've driven the centre. That's great !After reconfiguring the message occurs"%MARS_NETCLK-3-CLK_TRANS: Network clock source transitioned from priority 10 to priority 1"And controllers are fine now :)2.Could you please also explain the mechanism of the fix ?As I've found in documentation, 'network-clock-select' justprioritizes clock sources if there are more than one.<< CITED BEGIN{ network-clock-selectWhen an active clock source fails, the system chooses the next lower priority clock source specified by this command. When a higher-priority clock becomes available, the system automatically reselects the higher-priority clock source.}<< CITED ENDThus it doesn't absolutelty clear for me what has been happened :)Both routers have had the same source, and the problem has been solved only after I had prioritized theirs sources. Hm...

Guest

Re:E1 PRI Clock Sourcing Question

Post by Guest » Sun Mar 21, 2010 2:09 am


Hi, what the manual doesn't say, is that the VWIC card MUST have the selected "network-clock" to be same circuit that is connected to, else slips will happen.Slips are not a serious problem for data and voice, but cause fax and modem to fail.Thanks for the appreciation and good luck!

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