[asterisk-users] PRI Test Lab

[Matt Florell]

On 2/13/09, Alex Balashov <abalashov at evaristesys.com> wrote:
>
>
>  On Fri, 13 Feb 2009 09:48:11 +0000 (GMT), Lee Wilson <leefm40 at yahoo.co.uk>
>  wrote:
>
>
>  > Alex, thanks for the quick response.
>  >
>  > So I can assume from your response this should work.  That was easy :-)
>  >
>  > I just want to clarify before I got and buy anything the cards are not so
>  > cheap.
>
>
> Yep, it should work.
>
>  I am not exactly sure how one goes about setting one of the cards to
>  provide the T1 master clock as I have only configured low-level T1 settings
>  on Sangoma cards, but it should be possible.  Although, honestly, I am not
>  sure that you're going to get a lot of timing slips on something like a 6
>  ft crossover cable anyway even if the clocks are both set to line or
>  internal;  timing synchronisation is much more of a concern on lengthier
>  spans and circuit designs that go through numerous network elements.

If you want to be able to set Master timing you will have to use
Sangoma cards, they allow you force the timing in the wanrouter
configuration. I have done extensive testing with crossover T1/E1/PRIs
and I even have a testing lab set up with servers that have quad T1
cards with crossover cables going between all of the ports. There are
no time slip issues, and you can run the T1 line for hundreds of feet
without issues on good cable. For the cable I would suggest buying one
of these:

http://www.smartronixstore.com/index.cfm?fuseaction=product.display&Product_ID=9
  (SuperLooper ISDN (PRI) Crossover Adapter)

They are fairly cheap and will save you the headache of making your own cables.

If you are using Sangoma cards you will have to configure Wanrouter
properly, but the Asterisk/zaptel side is fairly easy to configure,
just make sure one side is pri_net and the other is pri_cpe and you
should be good to go.

MATT---