Cisco Cisco TelePresence Video Communication Server Expressway
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Media between the Lync client and the B2BUA can be routed in a number of ways, depending on the ICE
(Interactive Connectivity Establishment) negotiation between the Lync client and the B2BUA. The options
(dotted red lines on the diagram) are:
(Interactive Connectivity Establishment) negotiation between the Lync client and the B2BUA. The options
(dotted red lines on the diagram) are:
a.
Lync Client - VCS Expressway - Gateway VCS - VCS Control - VCS Expressway - External endpoint
b.
Lync Client - Lync Edge - Gateway VCS - VCS Control - VCS Expressway - External endpoint
c.
Lync Client - Lync Edge - VCS Expressway - Gateway VCS - VCS Control - VCS Expressway - External
endpoint
endpoint
Note:
The exact media path for any particular call is impossible to determine until the call is made. This is
because the clients perform the connectivity checks and candidate sorting each time the media path is
established, and route selection is based on loosely regulated factors. See
established, and route selection is based on loosely regulated factors. See
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Media between the external Cisco endpoint and the B2BUA flows through the secure traversal zone between
VCS Control and VCS Expressway.
VCS Control and VCS Expressway.
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Calls made in the opposite direction (external Cisco endpoint to external Lync client) use the same signaling
and media paths.
and media paths.
Off-site Lync Client Calls Internal SIP Video Endpoint
Figure 8 Call between off-site Lync client and internal SIP endpoint.
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Cisco VCS and Microsoft Lync Deployment Guide
Media Paths and License Usage