Differences

This shows you the differences between two versions of the page.

--- sip:fent [2010/11/09 11:05] – created tibor
+++ sip:fent [2010/11/09 11:49] (current) – tibor
@@ Line 3: / Line 3: @@
 The Internet Gate can enable SIP connectivity for remote users that use NAT devices without SIP support. It can adapt to characteristics of remote NAT devices.
-You might need to purchase a [[:license]] to be able to use FENT in your unit.
+**Using FENT you can allow people behind non-SIP-capable NAT firewalls to register on your Internet Gate's SIP server.**
-FENT sends keep-alive packets to remote SIP clients behind non-SIP-capable firewalls to keep the SIP communications channel free to them.
+:!: You might need to purchase a [[:license]] to be able to use FENT in your unit.
+You configure FENT on the [[:web GUI:Advanced SIP Settings]] page.
+FENT sends keep-alive packets to remote SIP clients behind non-SIP-capable firewalls to keep the SIP communications channel open to them. The keep-alive packets are SIP messages that are sent more often than the remote firewall's timeout.
+{{:sip:fent_1.png|Far End NAT Traversal}}
+There are two methods used for keep-alive:
+  * **REGISTER**: by lowering the REGISTER expiration timeout the SIP client behind the remote NAT will REGISTER often enough for keeping the connection open.
+  * **OPTIONS**: the Internet Gate will send SIP OPTIONS messages at regular intervals to the client behind the remote NAT, keeping the connection open.
+You can enable both methods, then the REGISTER method is tried first and if it does not work properly the OPTIONS method is used.
+===== Shortest media path =====
+By enabling **Detect endpoints behind same NAT** you allow SIP clients behind the same remote NAT making local calls to each other to send media locally between them on that LAN.
+{{:sip:fent_2.png|media on remote LAN}}