Interoperability

One specific use case that Lync does not solve on its own is the capability to conduct a conference using many types of endpoints. The Lync MCU can host a meeting with Lync endpoints and third-party endpoints using native Lync registration, but there is no support for any other third-party systems or partners to join a Lync meeting using traditional video endpoints.

Using a third-party MCU for hosting a meeting can allow both Lync endpoints and traditional video endpoints to participate in a single meeting. These meetings typically are limited to audio and video only because the protocols used for content sharing differ, but there are some workarounds that have been implemented, such as sending the content share as a video stream to Lync endpoints.

Cisco endpoints are unable to join any Lync Meetings because they do not register to the Lync server at all. The B2BUA signaling gateway provides presence updates for the Cisco endpoints, but does not facilitate any kind of conferencing or C3P support, so calls between VCS endpoints and Lync are limited to two-party connectivity.

The only form of conferencing available between Cisco and Lync endpoints must occur on a Cisco MCU or more advanced codecs that include a built-in MCU that Cisco refers to as Multiway. Lync endpoints can be joined into a Multiway conference, which is hosted on the Cisco endpoint rather than a dedicated MCU. These built-in Multiway bridges typically scale up to about four calls, which actually covers a good majority of ad hoc or smaller conferences.