IP Network Services
Polycom®, Inc. 392
FW (Firewall) NAT Keep Alive
The Collaboration Server can be configured to send a FW NAT keep alive message at specific Intervals
for the RTP, UDP and BFCP channels.
This is necessary because port mappings in the firewall are kept open only if there is network traffic in both
directions. The firewall will only allow UDP packets into the network through ports that have been used to
send packets out.
By default the Collaboration Server sends a FW NAT Keep Alive message every 30 seconds. As there is
no traffic on the Content and FECC channels as a call begins, the firewall will not allow any incoming
packets from the Content and FECC channels in until the Collaboration Server sends out the first of the FW
NAT Keep Alive messages 30 seconds after the call starts.
If Content or FECC are required within the first 30 seconds of a call the FW NAT Keep Alive Interval should
be modified to a lower value.

To enable and modify FW NAT Keep Alive:

FW NAT Keep Alive is enabled in the New Profile - Advanced dialog box.
»Select the FW NAT Keep Alive check box and if required, modify the Interval field within the range
of 5 - 86400 seconds.

System Configuration in SBC environments

In an environment that includes SAM (a Polycom SBC), to ensure that a RealPresence Mobile endpoint
can send content to a conference the value of the system flag
NUM_OF_INITIATE_HELLO_MESSAGE_IN_CALL_ESTABLISHMENT must be set to at least 3.