After the deployment of Cloud Connector (or any telephony option) the first question administrators usually ask is how good the call quality is? Microsoft has a nice tool Call Quality Dashboard which allows seeing and analyzing call quality. The detailed description of Call Quality Dashboard is here
First a little bit of theory.
When a client places a call there are two streams going on, the first one is RTP and the second is RTCP. RTP stands for Real Time Protocol and is used to transmit audio and video. RTCP is Real Time Control Protocol and is used for controlling the media flow and also used to collect network information during the call. Such statistics includes measuring network jitter, round-trip, packet loss. After a call client combines the data about devices, client versions, network ranges and many others, includes network statistics the client received from RTCP, and sends in a “Service” message to Skype for Business Online servers that processes the data and publishes it on tenant’s Call Quality Dashboard. Note there could be a delay up to 48 hours between client sent the data and seeing it on Call Quality Dashboard. The delay caused by internal processing jobs.
You can find the data sent by the client in local client logs. Find a “Service” message after a call, and you will see what parameters the client sends.
Note the client does not send the logs if a call which was 5 sec or less.
Now the data is in Call Quality Dashboard, the question is how to see the data about PSTN calls that were made using a Cloud Connector. If you look at CQD, there is information about all audio streams, including peer to peer VoIP calls, audio, and video conferences. There is also a chance that you might have Microsoft PSTN calling for users in the US or UK while providing PSTN services using a hybrid voice option in countries where Microsoft PSTN Calling is not available.
You can distinguish hybrid voice PSTN calls from any other calls you can use a parameter called “First User Agent” and filter by RTCC/18.104.22.168/*
Back to the theory again. Parameters “First User Agent” and “Second User Agent” capture endpoints which were used in the particular call. On the screenshot below, an example of “First User Agent” endpoints from one of the tenants. End users utilized these devices when placing or receiving the call. The similar list you will see for the “Second User Agent”.
The very important point is that when an endpoint places a call to a service or receives call from a service (not a peer to peer call), the service endpoint is always reported in “First User Agent” regardless of a call flow and who call whom.
The service which handles calls for Cloud Connector users is on-premises mediation server, which has version 22.214.171.124/* If you have calls that went through Microsoft PSTN calling the Mediation server version will be 7.0
Based on these two factors to distinguish Hybrid PSTN calls from all other audio streams you need only apply the filter:
“First Usage Agent” = RTCC/126.96.36.199/*
On screenshot is basic representation Dimensions, Measurements and Filters configuration to see Hybrid voice calls.
You can configure additional filters, for example, see network parameters during calls, or media connectivity issues to troubleshoot issues with call quality. You can find how to configure CQD to troubleshoot networks in Skype Operations Framework. In this blog, we want to show how to distinguish Cloud Connector calls from other calls.
The result shown on the screenshot below.
Question: I see many RTCC/188.8.131.52/LyncSkypeGateway/* as a “First User Agent” is it related to hybrid voice?
Answer: No, these are gateways the service uses to place calls between Skype and Skype for Business users
Answer: These are forwarded calls. Imagine the situation where an end user received a call on a Lync Client but set forward to another number; the call goes back to mediation server to make an external call.
Question: Why in some cases I see no data about call quality or network parameters?
Answer: There are several cases when this data is not available:
- Calls to voice mail don’t send the data;
- About 1% of sending the data might not reach the processing service. This is service limitation and we allow some data not reaching the service;
- Forwarded calls also do not have the call quality data (will be fixed soon)