PLAR connections

[Dmitry Podtikhov]

Hi

I have a router connected to the PBX via full PRI trunk.

We have a need to implement PLAR connections from several remote sites (which are connected to the main site via IP network) to the analog phones connected to the PBX . The requirement is that this plar connections must be set up regardless of the current number of calls, so i need to reserve several timeslots for that. There is no CCM or CCME in my setup.

I'm trying to find optimal way to implement this.

My idea is to use ATA186 adapters at each remote site with PLAR connection set to the main router. Do I need to cut some timeslots from the PRI-group at the main site router and  to get this PLAR connection work? Or is it somehow possible to implement it using the same pri group? Maybe it's better to use fxs cards instead of ATA adapters?

[Clifford McGlamry]

You can do it either way.  But the bigger question is that if you MUST put through the PLAR calls, does it require one to one subscription rates, or can it be oversubscribed (if it's oversubscribed, not all the PLAR calls can get through).  If you can oversubscribe it, someone has to figure out what an acceptable oversubscription rate would be.

Because you don't have CCM in the mix, you can't run MLPP to cause an active call to be dropped to put through the PLAR.

If you're attempting to peal out timeslots, I'm honestly not sure if you can pull it off with a PRI.  Fractional PRI configurations have been discussed a few times in this community, but I've never seen a config of one that actually worked.  If you need a fractional circuit of dedicated channels, it's probably going to be easier to go with a CAS circuit.  Those can be divided up fairly easily.

Cliff