support "empty" SCCP N-Connect from MSC

Teach osmo-bsc to handle empty N-Connect. So far we were always
expecting user data in an SCCP N-Connect from an MSC. However, it is
perfectly valid for an initial BSSMAP request to follow later.

This is relevant for:
- Handover Request (incoming inter-BSC handover)
- Perform Location Request (query physical location of the MS)

Add state WAIT_INITIAL_USER_DATA with new timeout net X25. Always enter
this state so that we don't have two separate code paths for handling
initial user data.

Related: SYS#5864
Change-Id: I535c791fa01e99a2226392eb05f676ba6c3cc16e

1 files changed, 2 insertions, 0 deletions

diff --git a/tests/timer.vty b/tests/timer.vty
index e83207015..04c987274 100644
--- a/tests/timer.vty
+++ b/tests/timer.vty
@@ -33,6 +33,7 @@ net: X14 = 5 s	Timeout for RSL Channel Mode Modify ACK (BSC <-> BTS) (default: 5
 net: X16 = 1000 ms	Granularity for all_allocated:* rate counters: amount of milliseconds that one counter increment represents. See also X17, X18 (default: 1000 ms)
 net: X17 = 0 ms	Rounding threshold for all_allocated:* rate counters: round up to the next counter increment after this many milliseconds. If set to half of X16 (or 0), employ the usual round() behavior: round up after half of a granularity period. If set to 1, behave like ceil(): already increment the counter immediately when all channels are allocated. If set >= X16, behave like floor(): only increment after a full X16 period of all channels being occupied. See also X16, X18 (default: 0 ms)
 net: X18 = 60000 ms	Forget-sum period for all_allocated:* rate counters: after this amount of idle time, forget internally cumulated time remainders. Zero to always keep remainders. See also X16, X17. (default: 60000 ms)
+net: X25 = 5 s	Timeout for initial user data after an MSC initiated an SCCP connection to the BSS (default: 5 s)
 net: X3111 = 4 s	Wait time after lchan was released in error (should be T3111 + 2s) (default: 4 s)
 net: X3210 = 20 s	After L3 Complete, wait for MSC to confirm (default: 20 s)
 mgw: X2427 = 5 s	timeout for MGCP response from MGW (default: 5 s)
@@ -86,6 +87,7 @@ net: X14 = 5 s	Timeout for RSL Channel Mode Modify ACK (BSC <-> BTS) (default: 5
 net: X16 = 1000 ms	Granularity for all_allocated:* rate counters: amount of milliseconds that one counter increment represents. See also X17, X18 (default: 1000 ms)
 net: X17 = 0 ms	Rounding threshold for all_allocated:* rate counters: round up to the next counter increment after this many milliseconds. If set to half of X16 (or 0), employ the usual round() behavior: round up after half of a granularity period. If set to 1, behave like ceil(): already increment the counter immediately when all channels are allocated. If set >= X16, behave like floor(): only increment after a full X16 period of all channels being occupied. See also X16, X18 (default: 0 ms)
 net: X18 = 60000 ms	Forget-sum period for all_allocated:* rate counters: after this amount of idle time, forget internally cumulated time remainders. Zero to always keep remainders. See also X16, X17. (default: 60000 ms)
+net: X25 = 5 s	Timeout for initial user data after an MSC initiated an SCCP connection to the BSS (default: 5 s)
 net: X3111 = 4 s	Wait time after lchan was released in error (should be T3111 + 2s) (default: 4 s)
 net: X3210 = 20 s	After L3 Complete, wait for MSC to confirm (default: 20 s)
 mgw: X2427 = 5 s	timeout for MGCP response from MGW (default: 5 s)