ISDN Clocking...

[mattKnight]

Are all ISDN circuits (regardless of provider) clocked in sync with one another? Obviously, E1 and T1 can't be...

Or are ISDN clocks free running and teh only requirement is fro the CPE to be in sync with the CO?

Take Care

Matt
I have always wished that my computer would be as easy to use as my telephone.
My wish has come true. I no longer know how to use my telephone.

 

[Sympology]

In theory they should all be synch'd with each other i.e. by an atomic clock. However there may be very slight (and we are talking slight) variations. However you can get slippage which can result in all kinds of strange behaviour.
In anycase, you should only be pulling clock master from one isdn line.
We use multiple telco's into the same switch and rarely does it cause an issue

Robert Wilensky:
We've all heard that a million monkeys banging on a million typewriters will eventually reproduce the entire works of Shakespeare. Now, thanks to the Internet, we know this is not true.

 

[mattKnight]

Thanks Symp,

That's what I thought; I have a strange issue with a phone system where I have 2 sites with 2 ISDN circuits on each, connected by IP. The second site has no master sync to the lines but appears (no reports otherwise) to work ok; except when theP link fails. When the IP link fails, the ISDN trunks at the remote site also fail (D channel falls out of service) - which points to a common carrier issue -except that the IP carrier and ISDN carriers are different. I am wondering if this is a clock issue.

Take Care

Matt
I have always wished that my computer would be as easy to use as my telephone.
My wish has come true. I no longer know how to use my telephone.

 

[IPGuru]

I dont think this is a sync issue but I would still set sync on the site to be its ISDN connection


I do not Have A.D.D. im just easily, Hey look a Squirrel!

 

[mattKnight]

IPGuru

Thanks
for anyone else
thread690-1641824


Take Care

Matt
I have always wished that my computer would be as easy to use as my telephone.
My wish has come true. I no longer know how to use my telephone.

 

[OBrienComms]

Hi Matt the answer is quite simple if you have two sites linked together site A and site B. Site A has the primary clock source and site B draws it's clock source from site A. If the link fails and site B has no secondary clock source to fall bask on the you may get sync problems. Solution is at site B select the secondary clock source as that sites ISDN trunk and all should be well in the world, at least thats the theory. Hope this helps.

 

[docjohn52]

Switchrooms in the US, now use satellite GPS satellites for timing, and are synced to what is known as System Network Clock, or snyc, ("Snik").

T1's DS3's, OCC, Digital Switching networks, all running in sync. While it is true, there is a master / slave end for a T-1, there is no sending office, because they're bi-directional.

All switchrooms have triple redundancy, and diversity. With diversity means that the fiber, or dishes enter the premises from more than one direction.

ISDN is two channels "nailed together" through a switch or 24, on a special flavor of T-1. When ordering ISDN, lose a channel, and insist on two "D" channels.