Requirements - Avaya Nortel Communication Server 1000 Manual

526 Appendix A NAT router requirements for NAT Traversal feature
The natcheck tool can be downloaded at no cost from the Internet at:
http://midcom-p2p.sourceforge.net/. The natcheck tool runs in Windows on
a PC connected to the internet through a NAT router.

Requirements

Cone NAT
The NAT Traversal feature cannot work unless the NAT device has a cone
NAT implemented.
Confirm using natcheck
Run the natcheck program. Look for the following message:
UDP consistent translation:
If YES is displayed, then the NAT router uses a cone NAT.
Confirm using IP Phone
The NAT router uses a cone NAT if no error message is displayed when the
IP Phone registers to the system. The NAT device does not use a cone NAT
if the IP Phone behind it displays the following error message:
NAT Error!
Please try upgrading firmware on the NAT device or
replacing it with a different NAT device that has a cone NAT
implemented.
Time-out configuration
Confirm using natcheck
Time-out configuration cannot be performed using natcheck.
Confirm using IP Phone
If the IP Phone connection times out and the IP Phone reboots, use LD 117
to lower the NAT Keep Alive Timer value on the Call Server. The reboots
could indicate that the NAT device address/port mapping is being cleared
because there is no message traffic from the IP Phone. By lowering the
NAT Keep Alive Timer value in the Call Server, keep-alive messages are
sent more frequently to keep the mapping "alive".
>ld 117
->chg nkt 20
If lowering the NAT Keep Alive Timer value to the minimum value of 20
seconds does not stop the time-outs, try replacing the NAT device.
Hairpinning
Hairpinning occurs when an IP Phone behind a NAT router can send packets
to the Public IP address and Port of another IP Phone connected to the
same NAT router. Determine if hairpinning is supported on the NAT router.
Copyright © 2003–2008, Nortel Networks
.
ITG3053
Nortel Communication Server 1000
IP Line Fundamentals
NN43100-500 02.02 Standard
Release 5.5 4 February 2008
YES (GOOD for peer-to-peer)