Bug #1759
openWrong calculation of DL window size for DL assignment
30%
Description
Hi,
When we create DOWNLINK TBF without existing UPLINK TBF i.e DL assignment on PCH case, The calculation of window size is found to be incorrect.
Description:
4 time slots is configured for DL and osmo-pcu.cfg is configured as window-size 64 104.
When we try to do IPERF in DL direction, PCU allocates window-size as 160 but configures 4 time slots
as seen by PCU VTY. Below is the result of VTY output.
DL TBFs
TBF: TFI=0 TLLI=0xf73d2ece (valid) DIR=DL IMSI=901555000001280
created=1095 state=0000000a 1st_TS=4 1st_cTS=6 ctrl_TS=6 MS_CLASS=0/1
TS_alloc=4 5 6! 7 CS=MCS-9 WS=160 V(A)=12 V(S)=12 nBSN=138
But we see proper calculation of window-size when DL assignement is done on PACCH. as seen by VTY interface below
DL TBFs
TBF: TFI=0 TLLI=0xf73d2ece (valid) DIR=DL IMSI=901555000001280
created=1095 state=0000000a 1st_TS=4 1st_cTS=6 ctrl_TS=6 MS_CLASS=0/1
TS_alloc=4 5 6! 7 CS=MCS-9 WS=480 V(A)=138 V(S)=139 nBSN=138
Thanks,
Aravind Sirsikar
Related issues
Updated by laforge about 7 years ago
- Assignee changed from arvind.sirsikar to 4368
Updated by laforge almost 7 years ago
- Assignee changed from 4368 to msuraev
- Priority changed from High to Normal
Updated by msuraev almost 7 years ago
I don't see explicit tests for it - only as part of larger TBF tests. So the first step would to add such a test.
Updated by msuraev over 6 years ago
- Project changed from Cellular Network Infrastructure to OsmoPCU
Updated by msuraev over 6 years ago
- Related to Feature #1533: Separate the window handling from the TBF more clearly added
Updated by msuraev over 6 years ago
- Status changed from New to In Progress
- % Done changed from 0 to 20
Related gerrit 5355, 5336-5341 are under review. Remaining parts: clearly differenciate between CCCH and PACCH assignment, figure out whyit makes a difference to window size calculations and test with different window sizes settings and available channels.
Updated by msuraev over 6 years ago
- Status changed from Stalled to In Progress
- % Done changed from 20 to 30
Patches were merged. Additional gerrit 5786 was sent for review.
Updated by msuraev over 6 years ago
The window size parameter in vty defined as follows:
window-size <0-1024> [<0-256>] Window size configuration (b + N_PDCH * f) Base value (b) Factor for number of PDCH (f)
So the configuration window-size 64 104
means that WS(1TS) = 64 + 1 * 104 = 168
and WS(4TS) = 64 + 4 * 104 = 480
. By default f = 0
.
Updated by msuraev over 6 years ago
- Related to Bug #1524: PACCH on the wrong timeslot added
Updated by msuraev over 6 years ago
In addition to difference between PACCH and CCCH, the TBF can be assigned via CCCH but configrmed via PACCH (see rcv_control_ack() function). This and the related #1524 makes it harder to reproduce this reliably.
Related gerrit 6239 is under review.
Updated by laforge over 6 years ago
Hi Max,
On Mon, Feb 05, 2018 at 03:45:50PM +0000, msuraev [REDMINE] wrote:
In addition to difference between PACCH and CCCH, the TBF can be assigned via CCCH but configrmed via PACCH (see rcv_control_ack() function). This and the related #1524 makes it harder to reproduce this reliably.
would it be possible to disable certain variants as a temporary hack?
Updated by msuraev over 6 years ago
- Status changed from In Progress to Stalled
Needs a way to reproduce this reliably.