Microsoft Lync B2Bua - Cisco TelePresence Administrator's Manual

Applications

Microsoft Lync B2BUA

The Microsoft Lync back-to-back user agent (Lync B2BUA) on the VCS is used to route SIP calls between
the VCS and a Microsoft Lync Server.
It provides interworking between Microsoft ICE (used by Lync clients) and media for communications with
standard video endpoints. It also provides call hold, call transfer and Multiway support for calls with Lync
clients, and can share FindMe presence information with Lync.
The setting up of the Lync B2BUA includes the following tasks:
Configuring and enabling the
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Configuring the transcoders
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through them (this is optional and are typically only used with Lync 2010).
Defining the B2BUA's
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Defining the set of TURN servers
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Setting up search rules to route calls to the Lync domain via the B2BUA — when the B2BUA is enabled a
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non-configurable neighbor zone (named "To Microsoft Lync server via B2BUA") is automatically
created; this zone must be selected as the target zone of the search rules.
A service restart is sometimes required to enable certain configuration changes to the Lync B2BUA to take
effect. A system alarm is raised if a service restart is necessary.
Microsoft Lync 2010
The Microsoft Interoperability option key must be installed to enable encrypted calls to and from Microsoft
Lync 2010 Server (for both native SIP calls and calls interworked from H.323). It is also required by the
B2BUA when establishing ICE calls to Lync 2010 clients.
The B2BUA can use the Cisco AM GW to transcode between standard codecs (such as H.264) and
Microsoft RT Video and RT Audio to allow high definition calls between Microsoft Lync 2010 clients and
Cisco endpoints.
Microsoft Lync 2013
The B2BUA provides interworking between standard H.264 AVC and Lync 2013's H.264UC SVC codec.
You can still configure the B2BUA to use Cisco AM GW transcoders with Lync 2013, but it is not necessary
and we recommend that they are not deployed with Lync 2013.
Lync 2013 no longer supports H.263, so X8.1 or later software is required to interoperate successfully with
Lync 2013. X7.2 or earlier software will work with Lync 2013 only if calls are routed through a Cisco AM GW
transcoder.
The Microsoft Interoperability option key is required for all types of communication with Lync 2013.
Usage features and limitations
The Lync B2BUA has a maximum simultaneous call capability of 100 calls (for all server sizes, including
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Large VM servers); however, calls that use transcoder resources count as 2 calls.
Cisco VCS Administrator Guide (X8.1.1)
B2BUA for Microsoft Lync
that may be used by the B2BUA and any
trusted hosts — the devices that may send signaling messages to the B2BUA.
available for use by the B2BUA when establishing ICE calls.
B2BUA (back-to-back user agent) overview
communications.
policy rules used to control routing
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