Solved: Best practice for CUCM media resources

Ammar Saood · ‎10-12-2021

Dear Cisco Community,

Let me hear from you all, please provide your best practices and the order of MRGs in the MRGL that you usually put. Considering that its a single site, and customer has a mix of Audio IP phones(SCCP + SIP) + Video phones. ITSP supports G711A&ULaw, and CUCM has a SIP trunk with CUBE. There is also an AutoAttendant configured on Unity connection with call transfer feature. You can also add Cisco CMS for Adhoc conferencing.

You can put everything in one device pool or more as you like. Internally it is preferred to have wideband audio codec wherever possible.

I want to know how you guys will implement media resources in this scenario to avoid codec mismatches and other common media resource issues.

Thanks,

Kaloyan · ‎10-29-2021

Hello Ammar,

Please refer to the Media Resource chapter of the SRND https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/srnd/collab12/collab12/media.html.

Since your customer has only one location, you can keep all of the media resources in one device pool. For simplicity, I would advise you to stick to G.711 for all calls. Otherwise, you can configure G.722 between the regions of the phones, so you can have them speak over G.722 for 1 on 1 calls.

However, it would be best to ensure that the region relationships between the phones, the media resources, PSTN gateways, Unity Connection, other UC applications, and so on are set with a codec preference list that has G.711 as the preferred codec. This will ensure optimal interoperability and avoid engaging transcoder resources.

As per the SRND, an MRG needs to be created for each media resource type and then they need to be ordered in the MRGL, so they can be prioritized correctly. For example, you'll have a dedicated MRG for the transcoders and a dedicated MRG for the MTPs. The MTPs should be placed higher in the MRGL in order to be prioritized. The reason for this is because the transcoders can serve as MTPs, but it would be a waste to use them as such. The same goes for the CMS bridge, you don't want to use it as an audio-only conference bridge, so the IOS or CUCM conference bridges should be placed higher.

Basically, when the media resources have overlapping capabilities, the most expensive media resources should be placed lower in your MRGL to ensure they are utilized only when they are really needed.

View solution in original post

Kaloyan · ‎10-29-2021

Hello Ammar,

Please refer to the Media Resource chapter of the SRND https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/srnd/collab12/collab12/media.html.

Since your customer has only one location, you can keep all of the media resources in one device pool. For simplicity, I would advise you to stick to G.711 for all calls. Otherwise, you can configure G.722 between the regions of the phones, so you can have them speak over G.722 for 1 on 1 calls.

However, it would be best to ensure that the region relationships between the phones, the media resources, PSTN gateways, Unity Connection, other UC applications, and so on are set with a codec preference list that has G.711 as the preferred codec. This will ensure optimal interoperability and avoid engaging transcoder resources.

As per the SRND, an MRG needs to be created for each media resource type and then they need to be ordered in the MRGL, so they can be prioritized correctly. For example, you'll have a dedicated MRG for the transcoders and a dedicated MRG for the MTPs. The MTPs should be placed higher in the MRGL in order to be prioritized. The reason for this is because the transcoders can serve as MTPs, but it would be a waste to use them as such. The same goes for the CMS bridge, you don't want to use it as an audio-only conference bridge, so the IOS or CUCM conference bridges should be placed higher.

Basically, when the media resources have overlapping capabilities, the most expensive media resources should be placed lower in your MRGL to ensure they are utilized only when they are really needed.