How to force media on CUCM/IOS router for Cisco IP Phones?

[raziel78kain]

Hello,

we have a quick question: is it possible to force the media on the CUCM and/or an IOS router for the Cisco IP Phones registered on that CUCM?

The scenario is the following: the networks of the 2 Cisco IP Phones can't "talk" each other directly, but they can "talk" with the network of the Cisco UC infrastructure.

TIA and regards.

[Jaime Valencia]

Use MTP or TRP, but if you're going to do this for every single call you need to place, you're going to need a lot of resources to make that work.

[raziel78kain]

Hello Jaime,

we have tried to configure the "Media Termination Point Required" check box on some Cisco SCCP phones, but we can't find it, so we could use the "Use Trusted Relay Point" check box on them.

Furthermore, we could configure some software IOS MTPs as TRPs, so we wouldn't need more DSP resources.

Is it right?

Regarding the usage of this option, we are going to activate it for a few teleworkers, so we don't need a lot of resources, at the moment.

Regards.

[Mohammed al Baqari]

Hi,

IOS MTP will consume CPU resources. Depending on your call intensity you need to keep an eye on IOS CPU/Memory usage especially if you are using high complexity codecs.

Furthermore, suggest to change the service parameter 'Fail Call if MTP Allocation Fails' to True. This will avoid scenarios where a call established without MTP/TRP which ends with silence. 

[raziel78kain]

Hello Mohammed,

of course, as soon as these teleworkers will increase to a greater quantity, we'll consider to add some hardware IOS MTPs.

Thanks for your suggestion about the service parameter.

Regards.

[Aseem Anand]

Hi,

If you are planning to use software MTP as TRP for few phones then you should be good. Below is the comparison of the different ISRG2 routers with regards to software MTP

https://supportforums.cisco.com/discussion/11948661/how-many-software-mtp-sessions-isr-g2-router-can-support

Aseem

[iverson.justin]

Thanks, how do you enabled TRP on SCCP phones?  

[Aseem Anand]

Hi,

You can use trusted relay point as Jaime suggested.

Refer to the link below:

http://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/admin/11_0_1/sysConfig/CUCM_BK_C733E983_00_cucm-system-configuration-guide/configure_trusted_relay_points.pdf

Aseem

[raziel78kain]

Hello Aseem,

it seems that TRP is the only option for SCCP phones, isn't it?

Regards.

[Aseem Anand]

Thats is correct.

Aseem