Aastra Telecom REV 06 - Manual (Page 124)

Features in Release 2.2
120 RN-001029-00, Rev 06, Release 2.2
IP Phone Release Notes 2.2
NAT Traversal Features
Configurable SIP and TLS Source Ports
A System Administrator can now configure the SIP and TLS source ports on the
IP Phone. Previously, the IP phone used default values (5060 for UDP/TCP and
5061 for TLS). The two new parameters for configuring the SIP and TLS source
ports are:
• sip local port
• sip local tls port
You can configure the SIP and TLS source ports using the configuration files or
the Aastra Web UI. After configuring these parameters, you must reboot the
phone.
If NAT is disabled, the port number also shows in the VIA and Contact SIP
headers.
If you enable NAT, the phone uses the NAT port number (and NAT IP address) in
the Via and Contact SIP headers of SIP messages, but still use the configured
source port.
Note: By default, the IP phones use symmetric UDP signaling for
outgoing UDP SIP messages. When symmetric UDP is enabled, the IP
phone generates and listens for UDP messages using port 5060.If
symmetric UDP signaling is disabled, the phone sends from random
ports but it listens on the configured SIP local port.