Polycom RealPresence RMX 4000, Administrator'S Manual

Page: 595 / 1101

Network Security
Polycom®, Inc. 564
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.
SIP Yes RealPresence
Access
Director  RealPresence
Access
Director Yes H.323
SIP Yes Acme Packet  Acme Packet Yes H.323
Business to Business Connections
Enterprise A Client Enterprise B Client
Environment Registered SBC SBC Registered Environment