VG analog ports and SRST

[peter.marr1]

I have a customer running multiple VG310s with SCCP and fallback settings to an SRST router.  When the VGs fail over to the SRST router, is there a way to prevent the unused analog ports from registering?  This customer wants multiple VGs to failover but there are too many analog ports for the licensing if all of them have to register.

Thanks,

Pete

[Robert Shaw]

Hi Pete,

The below blog may be of use to you.  It's an interesting problem.  All of my gateways are H.323 which provides greater flexibility but on the flip side isn't as easy to configure from Call Manager.  For me going H.323 would be the preferred solution to this, however, some of the points raised in this blog might work for you.  Admittedly this is talking about the older VG224 but the principles should still be the same.

https://reloadin10.com/2011/11/02/srst-w-vg224-using-mgcp-for-fun-and-profit-2/

Hope this helps.

Thanks
Rob

[peter.marr1]

Thanks Rob, very interesting but I'm not in a position to migrate the VGs to H.323.  I'm wondering if removing the stcapp service from the dial peers would stop the associated ports from registering?

Thanks,

Pete

[Robert Shaw]

Hi Pete,

I came across a couple of links to some older posts that may be of use.  Looks like you should be able to use a mixture of stcapp and registering different ports to different device pools.  Unused ports to a Device Pool without an SRST reference and used ports to a Device Pool with SRST enabled.

https://supportforums.cisco.com/document/12450616/stcapp-how-configure-fxs-ports-cucm

https://supportforums.cisco.com/discussion/10906046/configure-several-ports-only-srst-vg224

Hope this helps.

Thanks
Rob

[peter.marr1]

Good info again Rob, thx.  What I'm finding out is that when a VG fails over to an SRST router, all the ports fail with it, regardless of device pools since the SRST router knows nothing of them.  A local voice guru has echoed the same, so I'm going to do some testing to see if I can figure this out.

Thanks for all the input, more to come.

Pete

[peter.marr1]

Ok, easy enough to prevent an unused VG analog/fxs port (I'm running sccp and stcapp service)  from registering with the SRST router: on the VG, just shutdown the voice port, or remove the port association from the dial peer.

The hard part is preventing a used analog port from registering to the srst router;  more to come.

Pete

[darren-newman]

Greetings...

Was there ever a difinitive solution for this either way?

Otherwise i have a customer who has thousands of analog ports on various VG310, VG320, VG350 analog voice gateway's...and where they want the ability to control which analog gateway ports register with the local ISR 4xxx series router / SRST voice gateway when in SCCP mode. The property is hopsitality and thier PMS system requires that the analog voice gateway's run SCCP, or not SIP, or H323, or even MGCP. But there are many analog ports on the various analog VG3xx series gateway's that are active but that do not nesessarily require SRST to function in SRST mode. The customer also has way more analog ports than even the largest ISR's can handle...is SRST even enforced on the ISR 4xxx series? Otherwise, Cisco needs a simple way to control which analog ports on thier various analog gateway's (VG3xx series) register to a local SRST router when running in SCCP mode...thanks very much

[kdotten36]

I'm running into the same issue. We have about three thousand analog devices and only a select group of life safety lines should failover to SRST. The device pools are assigned as required but when the VG350 fails over, all fxs ports register to the SRST router. Our model can only register a max of 1200, so I have no way of determining which devices get SRST and which don't.

As mentioned earlier, all of our unused ports are shutdown, so that's not an issue. We have non-critical lines that we don't want to failover, like faxes, etc. By design, I thought the device pool assignment controlled this, but in practice, that's not the case.

Checking this thread in case anyone has found resolution before opening a TAC case. Thanks.

[ben.laakso]

Just wondering if you did open a TAC case to see if you could select which ports registered in SRST mode.  Any resolution?

Having the same issue.

[kdotten36]

Sorry for late reply. Must have went to spam.

I did open a case and it is not possible to limit the ports since CUCM delivers the SRST config to device, which is the gateway, not ports/protocols dependent on the gateway. Pasting TAC's response below...

The SRST config/ reference could only be delivered to the device which should save the config. Example is a IP-phone. When you login to phone console page you will see the SRST reference there. But for analog phones this is delivered to the particular port and is independent of protocol you are going to user to get it register.

This is how it is designed. You may reach to your account manager for any feature request but I am not sure if the design you are requesting is feasible or not.