Bug #2407
N3101 not implemented in OsmoPCU
100%
Description
N3101 is a counter. It counts up for every time no uplink data is received for an assigned USF.
Every time uplik data for an assigned USF is received, the counter is reset to zero.
If the counter ever reaches N3101_MAX, then the USF is no longer placed on the downlink, T3169 started and runs to expiry. After T3169 expiration, the USF is released and can be used by other TBF/MS.
Related issues
History
#1 Updated by laforge over 2 years ago
bts->n3101 is actually N3101_MAX, and it is provided via PCU socket from the BTS. So we already have a configurable N3101_MAX, but we have no actual per-USF/TBF counter and related mechanism.
#2 Updated by laforge about 2 years ago
- Assignee deleted (
laforge) - Priority changed from Normal to High
#3 Updated by laforge about 2 years ago
- Assignee set to msuraev
- Priority changed from High to Immediate
#4 Updated by msuraev about 2 years ago
- Status changed from New to In Progress
The counter and timer are described in 3GPP TS 44.060 §13.2 and §13.4
#5 Updated by msuraev about 2 years ago
- Related to Bug #2586: fix timer duration calculations added
#6 Updated by msuraev about 2 years ago
- % Done changed from 0 to 10
This change is less trivial than initially anticipated: the problem is with TBF timeout handling in OsmoPCU - there's only single osmo_timer_list which is used for handling of all the timeouts. This in turn means that TBF cannot have 2 concurrent timers running at the same time - the moment we schedule new timer, we lose the information about any pending timer for this TBF. This is both counterintuitive and unnecessary fragile which makes it hard to test and modify.
Related gerrit 5109 has been merged, gerrit 5120 and 5158 are under review. Once it's merged we'll have generic infrastructure in place for handling TBF timers. Follow-up patches will convert remainig timers to use it (including T3169) which would allow use to properly integrate N3101 support.
#7 Updated by msuraev about 2 years ago
- Related to Feature #2709: use osmo_fsm for TBF added
#8 Updated by msuraev about 2 years ago
- % Done changed from 10 to 70
Tested successfully with sysmoBTS, under review in gerrit 5158, 5182.
#9 Updated by msuraev about 2 years ago
- Status changed from In Progress to Stalled
#10 Updated by msuraev about 2 years ago
- Status changed from Stalled to Resolved
- % Done changed from 70 to 100
N3101 implementation has been merged, remaining patches to convert timer handling to the same infrastructure which is used for T3169 are under review.
#11 Updated by laforge almost 2 years ago
- Status changed from Resolved to Closed
