Extract RTP/RTCP information from CUCM when streams end and reoriginate there

[delr]

Good Afternoon, I just want to know if there is a way to extract information of RTP streams when streams end and reoriginate there via MTP or TRP resources, even if its posible to enable RTCP in CUCM to take statistics of those streams at CUCM side, for not deppending only of RTCPs at Phone's Side.

Thanks.

[Mohammed al Baqari]

Not sure if I understand correctly but IOS MTP Version 15.2(2)T and later supports RTCP pass-through

[delr]

Hello, It isnt related to IOS, but for CUCM.

Yesterday I found that CLI has the show media streams command, I dont know if this is the only way to check the RTP streams in CUCM:

http://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/cli_ref/9_1_1/CUCM_BK_C6AE17AA_00_cucm-cli-reference-guide-91/CUCM_BK_C6AE17AA_00_cucm-cli-reference-guide-91_chapter_0111.html#CUCM_CL_SAAC78C6_00

[Jonathan Schulenberg]

What are you trying to accomplish here? The wording you used is really confusing. Are you trying to get post-call quality measurements or something else?

CUCM does not proxy calls unless an MTP is invoked and even then only if the MRGL uses an IPVMSA software MTP on a CUCM node. Call media typically flows directly between phones and/or gateways.

If you want call quality statistics you must enable RTCP. The phones will give CUCM the RTCP report data to CUCM if you have enabled CMR logging in addition to CDR. The trouble here has been that only one or two gateway configurations will get that CMR data sent to CUCM from the gateway side (RTCP data is unidirectional so both call participants need to upload their reports).

In the absence of CMR data you would need a Network Analysis Module (NAM) in the traffic path to observe the RTP traffic and determine call quality data without the accompanying RTCP reports.

[delr]

Hello, in fact my question was very clear, at first I mention the CUCM in cases when MTP or TRP are invoked in CUCM resource and the RTP stream from the Phone end like this:

Phone<-------RTP------->CUCM(MTP or TRP)<-------RTP------->Destination (Phone, GW, Trunk, etc)

With this behavior, how could I get the media stream information from the CUCM ? I already enable the RTCP on the Phone, but Is there no way to cross-check the RTP or RTCP information also on the CUCM Side?, specially when someone want to check the quality of streams in and out from CUCM resource.

Regards.

[avinsrid89]

Hello,

1) You may use RTMT to monitor MTP/TRP statistics and check when they are invoked.

2) "show media streams" is also very useful command in CUCM. Run this command on the server the MTP is located, not registered.

3) CCM traces also give very useful information on MTP invoke and destroy.

4) CDR/ CMR records are very useful for call statistics.

Does this answer your question?

~Avinash

[delr]

Hello, thanks for your answer. I was wondering in another method for extract RTP streams info besides CMRs or CUCM Traces, because CUCM CMR werent as accurate in our operation, and CUCM traces could be intensive in busy-hours.

When you mention that we can monitor MTP/TRP statistics are you refering only to Performance Counters or there is more information of MTP/TRP that CUCM could deliver?

Regards.

[Jonathan Schulenberg]

So what you want to know is the five-tuple (source/destination IPv4 addresses, protocols, and port numbers) for calls?

The only way you'll be able to get that information is through a new API - new enough that it isn't even documented on Cisco DevNet - in CUCM 11.0. The API is intended to be used with APIC-EM and will feed real-time five-tuple information to APIC-EM so it can enforce policy, typically QoS.

The only other place that you would be able to see that information is in the CDR records. You can configure CUCM to push these records to an SFTP/FTP server at regular intervals. Your application would then be responsible for parsing the data. The five-tuple could be determined from these fields:

• origMediaTransportAddress_IP
  This field identifies the v4 IP address of the device that originates the media for the call.
• origMediaTransportAddress_Port
• destMediaTransportAddress_IP
  This field identifies the v4 IP address of the device that terminates the media for the call.
• destMediaTransportAddress_Port

Deciphering IP addresses is documented here: http://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/service/10_0_1/cdrdef/CUCM_BK_CBB143DE_00_cucm-cdr-administration-guide-100/CUCM_BK_CBB143DE_00_cucm-cdr-administration-guide-100_chapter_010.html#CUCM_TK_C6CDDF70_00

[delr]

Ok, I understood, thats what I want to know, the five-tuple . I was thinking that could be important, as we have issues with CUCM CMRs that are reporting bad MOS's of calls around 2.0 or 3.0 , but even if I took EPCs for those calls and I didnt percive such bad quality at all, so I was searching for other data sources

Thanks.

[Mohammed al Baqari]

Hi,

As Avinash mentioned, RTMT can provide you about the count of media streams per MTP. Also, you can use show media streams on CUCM to see more details per stream (codec, packet counts, dscp marking, etc)

If you are looking for QoS information, MTP won't send RTCP report back to CUCM. Therefore, you can't get quality information (latency, jitter, packet loss) from CMR reported by MTP devices. These devices can passthrough RTCP only.

Only IP Phones can send RTCP report and CMR can provide quality report for their streams.