1. Go to Account-Basic to configure.

Outbound proxy server


Outbound Proxy Server is used to receive all initiating request messages and route them to the designated SIP server.

 For example:
Outbound proxy server


Transport Type


Transport Type: To display and configure transport type for SIP message.
UDP: UDP is an unreliable but very efficient transport layer protocol.
TCP: Reliable but less-efficient transport layer protocol.
TLS: Secured and Reliable transport layer protocol.
DNS-SRV: DNS record for specifying the location of services.

NAT


NAT: To display and configure NAT settings.
STUN: Short for session traversal utilities for NAT, a solution to solve NAT issues.


2. Go to Account-Advanced to configure.

NAT


UDP Keep Alive message: If enabled, the phone will send UDP keep-alive message periodically to router to keep NAT port alive.
UDP Alive Msg Interval: Keep alive message interval.
Rport: Remote port, if enabled, it will add remote port into outgoing SIP message for designated account. 

User agent


One can customize user agent field in the SIP message. If user agent is set to specific value, users can see the information from PCAP. If user agent is not set by default, users can see the company name, model number and firmware version from PCAP.