Lync uses a number of different protocols to operate, and it can sometimes be confusing keeping track of which one does what. This is a short overview of the protocols in Lync and what they are for. Continue reading “Protocols used by Lync” »
It’s common for a UCMA app, before answering an incoming audio call, to perform some setup steps: finding an agent to take the call, preparing media, whatever. These steps may be necessary if, for example, the call is being set up as a back-to-back call and they can’t be done after the call is already established. In other cases, the way the call is set up makes the actual process of accepting the call take some time. Unfortunately, this can lead to callers hearing multiple seconds of ringing (or, even worse, silence) before the call is fully established. It can also lead to “clipping” effects where the beginning of a message or someone’s greeting is cut off because the media flow isn’t quite established yet. A feature called “early media” allows your application to get around these limitations and eliminate most of that delay or clipping. Continue reading “Shortening the “answer delay” with early media” »
The latest cumulative update for Lync was recently released, and one of the fixes deals with an interesting problem to do with audio conferences. I thought I would take the opportunity to discuss a few things about how media works in a Lync audio conference, and the implications of this change in the update.
The fix that I’m referring to (details here) resolves a problem where one-way audio could occur between a client and an audio/video MCU. For background, the MCU, or multipoint control unit, is the Lync component that mixes media for the conference and distributes it to the participants. What was happening in certain cases was that an audio conference participant would be audible in the conference, but could not hear other participants.
It turns out that the reason for this was an issue with media encryption in the MCU. Continue reading “A/V MCU encryption fix in Lync CU4” »