Using IPO as tandem.

[edlau]

Hello, is this configuration possible?

I have two IPO connected with SIP trunks between them, and it is working good with extensions (in both ways).
But only one IPO has one PRI connection to the PSTN, and I need that the other IPO could access this PRI using the SIP Trunks, using the first IPO as a tandem PBX.

Any help or comment will be appreciated.

Thanks,
Eduardo.

[willems1]

Build an SCN between the two IPO's and access the PRI through specific dial prefix.
That should do it.

[pdgavin]

Using IPO as tandem.

An SCN requires H323 trunks to network the two switches together, since you already have SIP trunks networking the two sites together it would cost more money to then add the H323 trunks. In either case you would still have to do some programming to use the SIP or H323 trunks to do tandem switching. Basically in the remote switch that does not have the PRI you would change the main ARS table and tell it to use the outgoing group ID of the SIP trunks that connect to the other switch and when someone wants to make a PSTN call and send the call over to the other switch but make sure to add a 9 in the telephone number field (assuming you are in the United States and use a 9 to dial out). You do not have to change to H323 trunks and SCN to get this to work although you can use a feature called Break Out dialing if you did.

Pete