Communication between 2 SRST enabled Routers

[SAURABH KUMAR]

Hi,

I have one scenario, I have 2 SRST enabled router A and B resp. in one location and during the fallback, The phones will get registered Router A and same with B. Now I want to know whether the Phones of A can communicate with Phones of B router during SRST fallback. Iff yes then how will both the routers will communicate with each other?

Thanks

Saurabh                     

[V.Naveen Kumar]

mainly SRST used to  provides call function for within site only.. whenever IPWAN failure

it wouldnt communciate with other site..

if you have any PRI connection it will use for outside call..

[SAURABH KUMAR]

Hello Naveen,

The phones which are registered at Router A can call each other directly during SRST, as both the routers are at the same location, in this case how will the phones of router A will communicate with phones of router B.

Thanks

[Roger Kallberg]

If I understand you correctly you have 2 SRST enabled GWs, GW A & GW B, at one location and some phones register to A and other phones to B.

You can get these GWs to communicate with each other with a VoIP dial peer. How the dial peer should be setup for the destination pattern would depend on if you have grouped your phones with ranges of DNs or if they are random distributed across A and B. Also if you use either SIP or H.323 as your normal service control protocol you would probably need to use a higher preference on the dial peer you want to use in SRST or build a EEM script that brings up the dial peer when any phone is registered to SRST and then shut it down once all phones have returned to normal operation.

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[charles.reid.10.ctr]

In Regards to this statement "You can get these GWs to communicate with each other with a VoIP dial peer. How the dial peer should be setup for the destination pattern would depend on if you have grouped your phones with ranges of DNs or if they are random distributed across A and B. "
We will have up to three SRST routers at one site to handle the number of phones that we want to register. Only one router will likely have a PRI for telco so we will need to route inbound and outbound PRI access across three routers AND route calls between the three routers for same site.

To enable inbound PRI, are routers smart enough in SRST to know to complete inbound calls to locally registered phones first and then use a dial-peer for router 2 and then a dial-peer for router 3 if the phone is not on router 1?

For outbound PRI we would just have an outbound dial-peer pointing to the router with the PRI.

Also, when calling among the phones between the three routers, the same situation, if calling a phone that isnt on the same router, is it as simple as having a dial-peer for each of the other two routers?

[Roger Kallberg]

The answer is pretty much yes. But there is a delay in the process of trying the next route, so it would be recommended to group numbers to get optimal routing for calls.

[charles.reid.10.ctr]

Ok, thank you, grouping numbers would be nice, but probably not possible, 12k phones, a few hundred device pools, but it would be nice. As long as it works, people will be happy.

[Maren Mahoney]

If devices in a specific device pool have related DNs (for instance all of the 571-555-23XX numbers are in a particular device pool), then you could assign a set of device pools that have related ranges (for instance all of the 571-555-[2-3]XXX numbers) to the same SRST reference. This would mean that a summarizable range of DNs would all register to a single SRST router. This might make the dial-peers for inter-router calls work.

I don't know if the distribution of DNs across device pools in your organization would make this possible, but it's a thought.

Maren