== Configuring OsmoMGW

A basic configation of OsmoMGW mainly consists of specifying the IP address
and port on which to listen to MGCP commands, but changing the port range at
which the RTP streams terminate as well as limiting operation to a single call
agent can be done as well as changing the number of endpoints.

=== Configuring MGCP

By default OsmoMGW listens for MGCP on port 2427 on any IP address. If a call
agent address is configured then OsmoMGW will only answer MGCP commands from
that IP port 2727, otherwise all sources are handled. A domain can be
specified

.Example: MGCP configuration
----
OsmoMGW(config-mgcp)# bind ip 127.0.0.1
OsmoMGW(config-mgcp)# bind port 2427
OsmoMGW(config-mgcp)# call-agent ip 127.0.0.1
OsmoMGW(config-mgcp)# domain mgw-bsc
OsmoMGW(config-mgcp)# local ip 127.0.0.1
----

=== Configuring the trunk

The first trunk (trunk 0) is considered a virtual trunk in OsmoMGW. All
endpoints of type "rtpbridge" are routed here. The virtual trunk is configured
in the config-mgcp context.

All other trunks are configured in the config-mgcp-trunk context, but the
commands used are identical. Right now trunks are considered only for ds/e1
type endpoints which are not yet implemented. Don't use trunks other than the
"virtual" trunk 0.

.Example: MGCP trunk configuration
----
OsmoMGW(config-mgcp)# number endpoints 63 <1>
OsmoMGW(config-mgcp)# rtp bind-ip 10.0.0.1 <2>
OsmoMGW(config-mgcp)# rtp port-range 12000-14000 <3>
----
<1> Maximum number of endpoints that can be allocated at once
<2> Use this IP when binding RTP endpoints
<3> Use ports in this range when binding RTP endpoints

There are some options to tweak how RTP forwarding behaves in OsmoMGW:

.Example: MGCP trunk rtp options
----
OsmoMGW(config-mgcp)# rtp keep-alive 30 <1>
OsmoMGW(config-mgcp)# rtp-patch ssrc <2>
OsmoMGW(config-mgcp)# rtp-patch timestamp <3>
----
<1> Send dummy UDP packets periodically to RTP destination
<2> Hide SSRC changes
<3> Ensure RTP timestamp is aligned with frame duration