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Bug #3333

lchan release may stall indefinitely

Added by laforge 13 days ago. Updated 13 days ago.

Status:
New
Priority:
Normal
Assignee:
Category:
A-bis RSL
Target version:
-
Start date:
06/11/2018
Due date:
% Done:

0%

Estimated time:
Spec Reference:

Description

When the MSC hard-releases the SCCP connection, we terminate the bsc_subscr_conn_fsm, which calls lchan_release(conn->lchan, 0, RSL_REL_LOCAL_END); from the fsm cleanup call-back.

That in turn causes a RLL_REL_REQ to be transmitted. However, if the MS never responds to that (out of reach, power-cycle, ...) there appears to be no timer running which would proceed with sending an RSL RF CHAN REL to actually release the channel.

This is currently triggered by TC_bssap_rlsd_does_not_cause_bssmap_reset involuntarily, as it tries to allocate 8 SDCCH.

Attaching a pcap file.

I'll add a dedicated test for this behavior.

20180611-lchan_rel.pcap 20180611-lchan_rel.pcap 1.67 KB laforge, 06/11/2018 03:54 PM

History

#1 Updated by laforge 13 days ago

New test provoking this problem is in https://gerrit.osmocom.org/#/c/osmo-ttcn3-hacks/+/9548

Assigned to neels as his existing work on lchan FSM will likely solve this bug.

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