There was always a 1:1 correspondence between gsm_subscriber_connection
and osmo_bsc_sccp_con, so there's really no point in having two separate
dynamically allocated data structures with pointers back and forth and
another linked list around.
Let's merge osmo_bsc_sccp_con into gsm_subscriber_connection for
simplicity.
The resulting code might not be elegant in places, but I've tried to
do only the most simple changes in this patch, while further
simplifications can be done in later subsequent patches.
As a side-effect, this patch also fixes lchan clearing if the MSC
(or the local SCCP provider) hard-disconnects the SCCP connection.
Change-Id: Idd2b733477ee90d24dec369755a00f1c39c93f39
Do not instruct the MGW to move the RTP to the new lchan before we have
received a HANDOVER DETECT.
Before:
Chan Activ
Chan Activ Ack
IPACC-CRCX
-ACK
IPACC-MDCX
-ACK
MGCP MDCX --> MGW
...
HANDOVER DETECT
Call continues on new lchan
In above sequence, if the HANDOVER DETECT times out, the MGW has moved to the
new lchan which never becomes used and is released. Furthermore, from the IPACC
MDCX until the HANDOVER DETECT, the RTP stream would break off momentarily.
After:
Chan Activ
Chan Activ Ack
IPACC-CRCX
-ACK
IPACC-MDCX
-ACK
...
HANDOVER DETECT
MGCP MDCX --> MGW
Call continues on new lchan
If the HANDOVER DETECT times out, the call happily continues on the old lchan.
This change is inspired by Ivan Kluchnikov's HO work, who implemented a similar
fix in the openbsc.git codebase (branch fairwaves/master-rebase): his patch
moves ipacc_mdcx() to connect RTP to the new lchan from switch_for_handover()
(which triggered on S_ABISIP_CRCX_ACK, i.e. creation of the new lchan) to later
on in ho_detect() a.k.a. the S_LCHAN_HANDOVER_DETECT signal handler:
http://git.osmocom.org/openbsc/commit/?h=fairwaves/master-rebase&id=9507a7a1ea627e07370c9d264816bb190b3b91b8
This patch does essentially the same: remove the mgcp_handover() call from the
MDCX-ACK handling (creation of the new lchan), and add a signal handler for
S_LCHAN_HANDOVER_DETECT to osmo_bsc_mgcp.c to effect the MGW switchover.
Note, it would have been possible to call mgcp_handover() directly from rx of
the HANDOVER DETECT message, but that produces linking fallout in some utils/
projects, which then need to link the mgcp code as well. That is because those
aren't properly separated from the more complex parts of libbsc. Using the
signal is a bit bloaty, but saves the linking hell for now. I've faced a
similar problem twice recently, it would pay off to separate out the simpler
utils/ and ipaccess/ tools so that they don't need to link all of libbsc and
osmo-bsc, at some point (TM).
Change-Id: Iec58c5fcc5697f1775da7ec0111135108ed1fc8f
A subsequent patch will add registration of a signal; cosmetically prepare by
creating a common mgcp_init() function. It makes sense for the FSM registration
to move to it.
Change-Id: I510e1081171706eb3d9fb2db50a9aa4f768929b5
when a transaction to the MGW times out, then the context
information is freed. Unfortunately the client is not informed
about this and will try to execute the callback anyway.
explicitly cancel the transaction in order to prevent access
to already freed data structures.
Change-Id: I40794dff7d10e2b6a96863a2da7e9fbd5662a1bf
osmo-mgw assigns connection identifiers which are returned with
the response to the CRCX.
store the assigned connection identifiers and use them to identify
the connections.
Depends: osmo-mgw Iab6a6038e7610c62f34e642cd49c93d11151252c
Closes: OS#2648
Change-Id: Ib379a6f40875bb8f2cf29038a5b5b7a40a21adab
osmo-bsc currently negotiates the RTP stream directly with the
BTS and reports back the RTP IP/Port on the BTS. This works fine
for a single BTS, but for Handover the port/ip pointing to the
MSC side must not change, so an entity in between the BTSs and
the MSC is required.
Integrate the mgcp-client and use osmo-mgw to switch the RTP
streams.
Depends: osmo-mgw Ib5fcc72775bf72b489ff79ade36fb345d8d20736
Depends: osmo-mgw I44b338b09de45e1675cedf9737fa72dde72e979a
Depends: osmo-mgw I29c5e2fb972896faeb771ba040f015592487fcbe
Change-Id: Ia2882b7ca31a3219c676986e85045fa08a425d7a
Harald Welte
Neels Hofmeyr
Philipp Maier