How are DID's associated with multiple PRI's

lewisa

Could any explain how the association works between DID's and PRI's please? I will post my scenario below for description purposes.

I currently have 5 PRI's and 500 DID's. On the voice gateway when an outbound call is placed it seizes the last channel of PRI 1. When an inbound call comes in it seizes the 1st channel of PRI 1. Can any one of these PRI's receive a call for any of these 500 DID's?

My next scenario is if I add 2 more PRI's from the same provider and 200 more DID's will these two PRI's be able to receive inbound calls for any of the 700 DID's or just the 200 DID's that was ordered with them?

I would greatly appreciate some clarification on this as I have been wondering about how this works.

Thank You,

shodown

You can setup in Call Manager how you use your PRI. You can do descending or ascending, which can grab the 1st or last channel depending on which option you chose. The provider will usually tell you how they are going to send calls in. If you order 2 more PRI's you can have all 700 numbers come across all of the PRI's you have. You just need your circuit ID's to let the provider know.

lewisa

Thank You shodown. This is exactly the information I was looking for. I will reach out to my provider and make sure all 700 DIDs are allowed across all of my PRI circuits.

aaron0011

The Telco assigns your DIDs to a trunk group, which contains your PRI circuits.

Our providers typically send incoming calls to channels in ascending order. I configure outbound calls from CUCM to use channels in descending order. In most cases I can look at the channel number and know if the call is inbound or outbound.

Is there a reason why your not considering SIP? With 7 PRIs you need a large router and a lot of VWICs. With that amount of DIDs I would use SIP trunks and CUBE.