[asterisk-users] Timing cable usage necessity

[David Backeberg]

2010/11/25 Захаров Антон <instnt at mail.ru>:
> Hello everyone.
>
> I have a timing slips errors and I can't understand what source of the
> problem is.
> My installation has 2 digium cards: TE420 and TE220 cards in one server.
> There are 3 spans (E1) to PSTN and 3 spans to internal PBS stations -
> normal installation for transit communication.
> Span configuration is:
> span=1,1,0,ccs,hdb3 #TE420 - first port. To PSTN.
> span=2,0,0,ccs,hdb3 #TE420 - second port. To PBX.
> span=3,2,0,ccs,hdb3 #TE420 - third port. To PSTN.
> span=4,0,0,ccs,hdb3 #TE420 - fourth port. To PBX.
> span=5,3,0,ccs,hdb3 #TE220 - first port. To PSTN.
> span=6,0,0,ccs,hdb3 #TE220 - second port. To PBX.
> I should to say, that PBXs are interconnected through router (doesn't
> know anything about it). So all schema looks like this:
> http://yfrog.com/jjschemaj
> Spans 1-5 works fine, but on span 6 (marked bold) I have rising timing
> slips counter.
>
> I think it's appearing because I'm getting a primary timing source on
> span 1 - first port on TE420. But TE220 doesn't use it's span 5 for
> timing source, because it has priority 3, so it could be a sync problem.
> Am I wrong?
>
> I'm started to think about timing cable for syncing timing on first card
> and second. Should I use it?
>
> It's a problem to bought cable in our city (Russia,Moscow). All
> resellers sell only cards. Could I use floppy or IDE cable to
> interconnect cards? As I see in picture of cable, it's a direct 16 pin
> cable.
>
> Does anybody know something about timing cable for different cards? How
> I can solve my problem?

I can't answer your problem about how you find one in Moscow, but I
can tell you that when I've installed two cards in a single server I
have used the timing ribbon cable. I have no idea whether it made a
difference, and I now build my servers differently. You could ask
Digium directly, as they probably know their resellers.

Something that may help you is that you can make sure you set the
priority on the cards differently from each other. There is a dial
with a pointer that tells you which card is prioritized. Whenever I
had two in the same server I made sure that one card was set higher
than the other.