Nat Hairpinning - Avaya 1000 Series Configuration Manual

• One way audio
- Ensure the phones and call servers are using STUN or a STUN like echo server for
UNIStim.
- Confirm the NAT port assignments using show firewall nat-translations all.
• Phones reboot or reset frequently
- Ensure the pings between the phones and the echo servers are being allowed to
traverse the firewall.
- Ensure the ping frequency is faster than the firewall UDP connection timeout.

NAT hairpinning

NAT hairpinning could be described as allowing endpoint devices on the internal side of a NAT
to communicate when using each other's external addresses and ports. Two scenarios where
hairpinning would be needed would be:
• A set of UNISTim, IP phones are deployed behind a NAT and the CS-series call server
is located on the public side. Here the CS-series call server will instruct the phones to
'talk' to each other on their apparent public IP addresses/ports.
• Any set of RTP based applications which are STUN aware are deployed behind a NAT
and a STUN server is publicly reachable. Here the STUN server will instruct the STUN
aware applications to 'talk' to each other on their apparent public IP addresses/ports.
Hairpinning must be configured through CLI using the following commands:
configure/firewall global > hairpinning-SelfIp
configure/firewall global > no hairpinning-SelfIp
Avaya Secure Router 1000 Series Configuration Guide
NAT hairpinning
December 2010 119