introduce erlang 'application' and corresponding config file
this replaces the use if '-define()' for stuff like NAT parameters
diff --git a/mgw_nat.app b/mgw_nat.app
new file mode 100644
index 0000000..4e61be2
--- /dev/null
+++ b/mgw_nat.app
@@ -0,0 +1,23 @@
+{application, mgw_nat,
+ [{description, "Media Gateway NAT"},
+ {vsn, "1"},
+ {modules, [mgw_nat_app, mgw_nat_sup, mgw_nat_usr, mgw_nat]},
+ {mod, {mgw_nat_app, []}},
+ {env, [
+ % SCCP rewrite
+ {real_hlr_gt, [6,3,9,1,8,0,0,0,4,0,1,2]},
+ {nat_hlr_gt, [3,5,4,8,9,0,0,0,7,1]},
+
+ % ISUP rewrite
+ {msrn_pfx_msc, [3,5,4,8,9,0,9,9]},
+ {msrn_pfx_stp, [6,3,9,2,9,9,4,2,0,0]},
+ {intern_pfx, [6,3]},
+
+ % SCTP / IP config
+ {msc_local_ip, any},
+ {msc_local_port, 2904},
+ {msc_remote_ip, {172,16,1,81}},
+ {stp_remote_ip, {172,16,249,20}},
+ {stp_remote_port, 2904}
+ ]}
+]}.