Item
Explanation
External IP
Address that we're going to put in outbound SIP
messages if we're behind a NAT
External Host
Alternatively, you can specify an external host, and
Asterisk will perform DNS queries periodically. Not
recommended for production environments! Use external
IP instead
External Refresh
How often to refresh external host if used. You may
specify a local network in the field below
Local Network Address
192.168.0.0/255.255.0.0' : All RFC 1918 addresses are
local networks, '10.0.0.0/255.0.0.0' : Also RFC1918,
'172.16.0.0/12' : Another RFC1918 with CIDR notation,
'169.254.0.0/255.255.0.0' : Zero conf local network
Item
Explanation
T.38 fax (UDPTL) Passthrough Enables T.38 fax (UDPTL) pass through on SIP to SIP
calls
Item
Explanation
TOS for Signaling packets
Sets Type of Service for SIP packets