pcu is logging "Allocating DL TBF: MS_CLASS=0/0" ; TLV parsing code commented?
This also relates to this error seen with EGPRS capable phone:
"Not accepting non-EGPRS phone in EGPRS-only mode"
However, in GPRS mode, this does not appear to make any immediately obvious difference to functionality, but all the same, MS_CLASS=0/0 is obviously wrong.
This is because the code to parse the MS RA Cap is commented, with a note:
"Do not rely on this IE."
As far as I can tell from analysis of NS trace, the BSSGP contains correct Radio Access Capability IE, that is to say, It is corresponding with what the MS sent in the Attach Request.
So why "do not rely?" Why is the code commented? Perhaps in 2016, this information from the BSSGP was not reliable?
and the two previous commits.
This ticket is a duplicate (talking about same issue) of #1525
We need to add some TTCN3 test to check emulation-SGSN sending this data to PCU and make sure it's taken into account.
Related code: gprs_bssgp_pcu_rx_dl_ud() (src/gprs_bssgp_pcu.cpp).
Related commits (from older to newer, they are together in history):
#8 Updated by pespin about 10 hours ago
According to some TTCN3 tests I'm doing, decode_gsm_ra_cap() is broken an returns an error, that's probably why it was commented out (probably they thought messages sent by SGSN were wrong, but actually decoding in PCU seems broken.).
I'm working on fixing it now.
#9 Updated by pespin about 10 hours ago
I just saw that csn1.cpp/csn1.hpp files are actually coming initially from wireshark. In current master, they are named:
I think it may make sense to try updating our code to match the one in wireshark instead of fixing this exact issue, because wireshark is decoding it fine.