#3199 (Mar 18, 2026, 11:43:09 AM)

s1gw: initial testcases for MME pooling

Three test cases covering the MME pool selection logic in OsmoS1GW:

* TC_mme_pool_reject_fallback: S1GW falls back to the next pool entry
  when the first MME rejects S1SetupReq with S1SetupFailure.
* TC_mme_pool_timeout_fallback: S1GW falls back when the first MME
  does not respond to S1SetupReq within the timeout.
* TC_mme_pool_all_reject: all pool entries reject S1SetupReq; S1GW
  must send S1SetupFailure to the eNB and tear down the connection.

Infrastructure added to support these tests:

* S1AP_Server.ttcn: S1AP_ServerList type; directed register/unregister
  helpers (f_ConnHdlr_s1ap_register_to / _unregister_from) for use
  when multiple S1AP_Server_CT instances are active simultaneously.
* S1GW_ConnHdlr.ttcn: f_ConnHdlr_s1ap_setup_pool() drives the pool
  setup sequence: pre-registers with all servers, sends S1SetupReq once
  (S1GW re-transmits it per-MME), then iterates through the expected
  behaviors (ACCEPT / REJECT / TIMEOUT) waiting for each server in turn.
* S1GW_Tests.ttcn: f_init_s1ap_srv(N) starts N MME emulators on
  consecutive IP addresses; f_TC_exec_pool() orchestrates pool tests.
* osmo-s1gw.config: a 'mme_pool' section with three entries is added
  alongside the existing sctp_client section.  Older OsmoS1GW (without
  pooling support) will use sctp_client to connect to a single MME and
  the pool test cases will simply fail, as expected.  Newer OsmoS1GW
  will use mme_pool and all three test cases will pass.

Change-Id: Ib8fd62e4352e3055971a669b8b363078bcd95d8d
Related: SYS#7052

s1gw: add testcases for impatient eNB during MME pool selection

Two new test cases covering scenarios where the eNB disconnects before
S1 setup completes, targeting specific states of the enb_proxy FSM:

* TC_mme_pool_enb_disc_wait_s1setup_req: eNB connects but disconnects
  before sending S1SetupReq (enb_proxy in wait_s1setup_req).  No MME
  connection is ever attempted; S1GW must handle the disconnect cleanly.

* TC_mme_pool_enb_disc_wait_s1setup_rsp: eNB sends S1SetupReq, S1GW
  forwards it to the first pool MME (enb_proxy in wait_s1setup_rsp),
  then eNB disconnects before the response arrives.  S1GW must detect
  the eNB disconnect and close the open MME connection in response.

A new helper S1GW_ConnHdlr.f_ConnHdlr_s1ap_close() is added for these
tests: unlike f_ConnHdlr_s1ap_disconnect(), it closes the eNB-side
socket without waiting for an S1APSRV_EVENT_CONN_DOWN from a pool
server (since in these scenarios either no MME connection exists
yet, or the CONN_DOWN is captured by the test body directly).

Change-Id: I5d27cdafcb9f595a2d3db59beff17cd55de2539e
Related: SYS#7052

s1gw: add tests for MME registry REST procedures

Add three test cases exercising the S1GW REST interface for MME pool
management.  The REST TCs are gated on the mp_rest_enable module
parameter in the control block.

TC_rest_mme_list: query the MME pool list via REST and verify it
matches the three static entries from the 'mme_pool' section in
osmo-s1gw.config (mme0/mme1/mme2 with their respective addresses).

TC_rest_mme_add_del: add a new MME entry at runtime via REST, verify
it appears in both the list and individual GET responses, then delete
it and confirm it is gone.

TC_rest_mme_del_fallback: delete mme0 from the pool at runtime and
verify that a connecting eNB is routed directly to mme1, skipping the
deleted entry.  The pool is restored to its original state afterwards
via f_REST_mme_pool_restore().

Also add:
* {ts,tr}_MmeItem templates to S1GW_REST_Types.ttcn
* f_REST_mme_find(): returns the integer index of a named entry in a
  MmeList, or -1 if not found; used for both presence and absence checks
* f_REST_mme_pool_restore(): deletes all current entries and re-adds
  mme0/mme1/mme2 in original order to keep pool state predictable
  across test cases

Change-Id: I260bc987ab8ae0ecb547d0b69b261fd97c5c9c23
Related: SYS#7052

s1gw: enable the REST interface, fix wrong REST port

REST had been disabled because only nightly builds supported it.
The latest stable release (v0.4.0) also supports the REST interface,
so let's enable it unconditionally by removing the mp_rest_enable.

Also fix the REST port: mp_rest_port was incorrectly set
to 8125 (the StatsD port) instead of the actual REST port 8080.

Change-Id: I012749076c652ab541e569026eb01c696ad5adc8
Related: SYS#7052, SYS#7066

s1gw: use REST interface to check PFCP assoc state

It's quicker to query the IUT using the REST interface rather than
waiting for StatsD metric "gauge.pfcp.associated.value" to be received.
As a bonus, we "learn" the local/remote RTS from the S1GW, which can
be used in new PFCP related testcases.

Change-Id: Iec7594e79f533b08ee93b443a39cb9c8ff03da43

s1gw: add README.md

Change-Id: Ib5c1326c4260bf552b561a42f7ff9d3f28f89579