Networks
Polycom, Inc.
57
Network Address Translation (NAT) network environments use private internal IP addresses for devices
within the network, while using one external IP address to allow devices on the LAN to communicate with
other devices outside the LAN. If your system is connected to a LAN that uses a NAT, you will need to enter
the NAT Public (WAN) Address so that your system can communicate outside the LAN.
To set up the system to work with a firewall or NAT:
1
In the web interface, go to Admin Settings > Network > IP Network > Firewall.
2
Configure these settings.
Setting
Description
Fixed Ports
Lets you specify whether to define the TCP and UDP ports.
•
If the firewall is not H.323 compatible, enable this setting. The RealPresence Group
system assigns a range of ports starting with the TCP and UDP ports you specify. The
system defaults to a range beginning with port 3230 for both TCP and UDP.
Note: You must open the corresponding ports in the firewall. For H.323, you must
also open the firewall’s TCP port 1720; for SIP you must open either UDP port 5060,
TCP 5060, or TCP 5061 depending on whether you are using UDP, TCP, or TLS as
the SIP transport protocol.
•
If the firewall is H.323 compatible or the system is not behind a firewall, disable this
setting.
For IP H.323 you need 2 TCP and 8 UDP ports per connection. For SIP you need TCP
port 5060 and 8 UDP ports per connection.
Range of UDP Ports: Because RealPresence Group systems support ICE, the range
of fixed UDP ports is 112. The RealPresence Group 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 to 3236, the second call uses ports 3236 to 3242,
the third call uses ports 3242 through 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 firewalls are filtering on source ports, go to Admin Settings >
Network > IP Network > SIP and enable the Force Connection Reuse checkbox.
When this setting is enabled, the system uses port 5060/5061 for the source port and
for the destination port. These ports are required to be open in the firewall.
TCP Ports
UDP Ports
Specifies the beginning value for the range of TCP and UDP ports used by the system.
The system automatically sets the range of ports based on the beginning value you set.
Note: You must also open the firewall’s TCP port 1720 to allow H.323 traffic.
Enable H.460 Firewall
Traversal
Allows the system to use H.460-based firewall traversal for IP calls. For more
information, refer to
H.460 NAT Firewall Traversal
.
NAT
Specifies whether the system should determine the NAT Public WAN Address
automatically.
•
If the system is not behind a NAT or is connected to the IP network through a Virtual
Private Network (VPN), select Off.
•
If the system is behind a NAT that allows HTTP traffic, select Auto.
•
If the system is behind a NAT that does not allow HTTP traffic, select Manual.
