Microsoft Lync B2BUA port reference
The port numbers listed below are the default port values. The values used in a real deployment may vary if
they have been modified, for example, by changes of registry settings or through group policy, on Lync and
Lync client, or configuration on VCS (
Applications > B2BUA
).
Between B2BUA and Lync
Purpose
Protocol
B2BUA IP port
Lync IP port
Signaling to Lync Server
TLS
65072
5061 (Lync signaling destination
port)
Signaling from Lync Server
TLS
65072
Lync ephemeral port
Presence to Lync Server
TLS
10011
5061 (Lync signaling destination
port)
Presence from Lync Server
TLS
10011
Lync ephemeral port
Media (the Lync B2BUA should be
deployed on a separate "Lync Gateway"
VCS and thus there should be no conflict
with the standard traversal media port
range)
UDP
56000 to 57000
Lync client media ports
Between B2BUA and VCS (internal communications)
Purpose
Protocol
B2BUA IP port
VCS IP port
Internal communications with VCS
application
TLS
65070
SIP TCP outbound port
Between B2BUA and VCS Expressway hosting the TURN server
Purpose
Protocol
B2BUA IP port
VCS Expressway IP port
All communications
UDP
56000 to 57000
3478 (media/signaling) *
Ensure that the firewall is opened to allow the data traffic through from B2BUA to VCS Expressway.
* On Large VM server deployments you can configure a range of TURN request listening ports. The default
range is 3478 – 3483.
External Lync client and Edge server
Purpose
Protocol
Edge server
Lync client
SIP/MTLS used between Lync Client
and Edge server for signaling (including
any ICE messaging to the Edge Server)
TCP
5061
5061
SIP/TLS
TCP
443
443
Cisco VCS Administrator Guide (X8.1.1)
Page 397 of 507
Reference material
Microsoft Lync B2BUA port reference