Polycom RealPresence Group Series Administrator's Manual page 105

Setting
Fixed Ports
TCP Ports
UDP Ports
Polycom, Inc.
Description
Defines which TCP and UDP ports your system uses
for firewall traversal.
Enable this option if your firewall isn't H.323
compatible. The system assigns a port range starting
with the TCP and UDP ports you specify (port 3230 is
where the range begins by default).
Note: For the fixed ports you configure, you must
open the corresponding ports on your firewall.
For H.323, open TCP port 1720. For SIP, open
UDP port 5060, TCP 5060, or TCP 5061
depending on if you're using UDP, TCP, or
TLS, respectively, as the SIP transport
protocol.
Disable this option if your firewall is H.323 compatible
or the system isn't behind a firewall.
The starting value for the range of TCP and UDP ports
the system uses. The system automatically configures
the range based on the beginning value you set here.
To allow H.323 traffic, you need two TCP and eight
UDP ports per connection. You must also open TCP
port 1720 on the firewall.
To allow SIP traffic, you need TCP port 5060 and eight
UDP ports per connection.
UDP port range: Because systems support ICE, the
range of fixed UDP ports is is 32, 62, and 82 for
RealPresence Group Series 300/310, 500, and 700
systems, respectively. The system cycles through the
available ports from call to call. After the system
restarts, the first call begins with the first port number,
either 49152 or 3230. Subsequent calls start with the
last port used. For example, the first call uses ports
3230-3236, the second call 3236-3242, the third call
3242-3248, and so on.
Fixed ports range and filters: You might notice that
the source port of a SIP signaling message is not in the
fixed ports range. When your firewall is filtering on
source ports, in the system web interface, go to the SIP
page and enable Force Connection Reuse. When
enabled, the system uses port 5060 and 5061 for the
source and destination port (these must be open on the
firewall).
Securing the System
103