Cisco Cisco Expressway Maintenance Manual
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 Expressway (
they have been modified, for example, by changes of registry settings or through group policy, on Lync and
Lync client, or configuration on Expressway (
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)
port)
Signaling from Lync Server
TLS
65072
Lync ephemeral port
Media (the Lync B2BUA should be
deployed on a separate "Lync Gateway"
Expressway and thus there should be no
conflict with the standard traversal media
port range)
deployed on a separate "Lync Gateway"
Expressway 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 Expressway (internal communications)
Purpose
Protocol
B2BUA IP port
Expressway IP port
Internal communications with
Expressway application
Expressway application
TLS
65070
SIP TCP outbound port
Between B2BUA and Expressway-E hosting the TURN server
Purpose
Protocol
B2BUA IP port
Expressway-E 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 Expressway-E.
* On Large VM server deployments you can configure a range of TURN request listening ports. The default
range is 3478 – 3483.
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)
and Edge server for signaling (including
any ICE messaging to the Edge Server)
TCP
5061
5061
SIP/TLS
TCP
443
443
STUN
UDP
3478
3478
UDP Media
UDP
50000-59999
1024-65535
TCP Media
TCP
50000-59999
1024-65535
Cisco Expressway Administrator Guide (X8.1.1)
Page 262 of 343
Reference material
Microsoft Lync B2BUA port reference