SRST solution with maximum capacity

[@Syed]

Hello All,

Hope you are all doing well!

I am looking for SRST solution, I have about 2500 phones and 2 CUCM nodes at branch office
and it is a critical site.

I see a risk in the current setup, as the voice gateways are residing at HQ datacenter, so if the WAN connectivity has to go down for a reason users at the site cannot
make external calls.

The idea is to introduce a router with maximum capacity with an additional SIP trunk as an alternative for external calling until the WAN is restored.

Could someone advise as to what are all the harware, license, pros & cons that I should be considering in order implement this remote site telephony solution.

Thank you

[Nithin Eluvathingal]

You need SRST license and you need to decide the router model based on the number of devices in remote site.

From below link you can decide the router model.

https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cusrst/requirements/guide/srs12spc.html

And also Go through CUCM SRND.

[Nithin Eluvathingal · Accepted solution]

i missed that you have CUCM node at branch. in that case u can ignore my reply. srst license is not required as the nodes are in branch you can add a gateway. as you are going with SIP trunk with ISP  consider CUBE license.

[Mohammed al Baqari · Accepted solution]

Hi,

If you have cucm nodes at the branch site, then just go ahead and buy an
ISR4 router to install it locally at the branch. Depending on the intensity
of the calls, you might go with ISR4331 with VSEC license which covers both
security and uc license with PVDM4-32 module. It will be packaged and good
to go. If you need additional modules like NIM-FXS-FXO for fax machines,
you can order it as well. This doesn't need an additional license.
Alternatively, you can order ATA-192 for fax conversion.

**** please remember to rate useful posts

[@Syed]

Thank you Nithin & Mohammed.

Appreciate your advise!