Configuring Ports For Connections From Traversal Clients - Cisco TelePresence Administrator's Manual

Firewall traversal
H.323 Assent call signaling port; default is 2776
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H.323 H.460.18 call signaling port; default is 2777
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Note that media demultiplexing ports are allocated from the general range of traversal media ports.

Configuring ports for connections from traversal clients

Each traversal server zone specifies an H.323 port and a SIP port to use for the initial connection from the
client. Each time you configure a new traversal server zone on the VCS Expressway, you are allocated
default port numbers for these connections:
H.323 ports start at UDP/6001 and increment by 1 for every new traversal server zone.
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SIP ports start at TCP/7001 and increment by 1 for every new traversal server zone.
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You can change these default ports if necessary but you must ensure that the ports are unique for each
traversal server zone. After the H.323 and SIP ports have been set on the VCS Expressway, matching ports
must be configured on the corresponding traversal client. Note that:
The default port used for the initial connections from MXP endpoints is the same as that used for standard
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RAS messages, that is UDP/1719. While you can change this port on the VCS Expressway, most
endpoints will not support connections to ports other than UDP/1719, therefore we recommend that you
leave this as the default.
You must allow outbound connections through your firewall to each of the unique SIP and H.323 ports that
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are configured on each of the VCS Expressway's traversal server zones.
The following table shows the default ports used for connections to the VCS Expressway.
Table 1: Default traversal port connections
Protocol Call signaling
Assent UDP/1719: listening port for RAS
messages
TCP/2776: listening port for H.225 and
H.245 protocols
H.460.18/19 UDP/1719: listening port for RAS
messages
TCP/1720: listening port for H.225
protocol
TCP/2777: listening port for H.245
protocol
SIP SIP call signaling uses the same port as
used by the initial connection between
the client and server.
* The default media port range of 36000 to 59999 applies to new installations of X8.1 or later. The first 2 ports
in the range are used for multiplexed traffic only (with Large VM deployments the first 12 ports in the range –
36000 to 36011 – are used). The previous default range of 50000 - 54999 still applies to earlier releases that
have upgraded to X8.1.
The call signaling ports are configured via
range is configured via Configuration > Local Zone > Traversal
Cisco VCS Administrator Guide (X8.1.1)
Media
RTP and RTCP media demultiplexing ports are
allocated from the start of the traversal media ports
range: UDP/36000-36001*.
RTP and RTCP media demultiplexing ports are
allocated from the start of the traversal media ports
range: UDP/36000-36001*.
RTP and RTCP media non-demultiplexing ports are
allocated from the remainder of the traversal media
ports range: UDP/36002-59999*.
Where the traversal client is a VCS, SIP media uses
Assent to traverse the firewall.
Configuration > Traversal >
Subzone.
Configuring ports for firewall traversal
Ports. The traversal media port
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