net: add mgw for osmo-bsc-nat

Start the OsmoBSCNAT's own instance of OsmoMGW. Launch it on a separate
IP, such as the other MGWs, so it's easy to differentiate in wireshark
which traffic relates to which MGW.

Related: https://osmocom.org/projects/osmo-bscnat/wiki/Ladder_diagrams_for_key_procedures
Change-Id: Iaeebb693c81d3aa4b1a46d2543c9872bd49b87c3

net/config_2g3g

@@ -96,6 +96,10 @@ MGW4BSC1_IP="127.0.0.11"
 MGW4BSC1_PORT="2427"
 MGW4BSC1_VTY_IP="127.0.0.11"
 
+MGW4BSCNAT_IP="127.0.0.14"
+MGW4BSCNAT_PORT="2427"
+MGW4BSCNAT_VTY_IP="127.0.0.14"
+
 BSC_COUNT=1
 
 BSC0_IP="${TO_RAN_IP}"

net/templates/osmo-mgw-for-bsc-nat.cfg

@@ -0,0 +1,16 @@
+${include(common_template_warning)}
+mgcp
+ domain bscnat
+ bind ip ${MGW4BSCNAT_IP}
+ bind port ${MGW4BSCNAT_PORT}
+ rtp net-range 50004 60000
+ number endpoints 1024
+line vty
+ bind ${MGW4BSCNAT_VTY_IP}
+
+${foreach(LOG_OUTPUT)}
+log ${LOG_OUTPUTn_TYPE}
+${include(common_logging)}
+ logging level rtp info
+ logging level lmgcp info
+${foreach_end}

net/templates/run.sh

@@ -244,6 +244,7 @@ if [ "${STP_CN_IP}" = "${STP_RAN_IP}" ]; then
 else
   term "$stp4cn" STP4CN
   term "$stp4ran" STP4RAN
+  term "$mgw -c osmo-mgw-for-bsc-nat.cfg" MGW4BSCNAT
   term "$bscnat" BSCNAT
 fi