Attention is currently required from: laforge, pespin, dexter.

View Change

1 comment:

• File src/common/rtp_input_preen.c:

  • Patch Set #3, Line 93: return PL_DECISION_STRIP_HDR_OCTET;

    my question here is: we are dropping some ToC information. […]

    Three-part answer:

    1. The information content in the ToC octet is a SID vs non-SID indication, similar to the ternary SID flag of GSM 06.41 section 6.1, but with the invalid-SID state disallowed, keeping only valid-SID and non-SID.

    2. At the present time there is no code anywhere in osmo-bts or even anywhere in Osmocom in general that does anything with this ToC octet other than ignore it. The old version of gsm0503_tch_hr_encode() function used by osmo-bts-trx would require 15-byte payload as input, yet never look at that extra byte.

    3. I do have a plan (OS#6036) to start making use of the SID classification info passed in the ToC octet for DTXd logic of OS#5996, taking the work I already did for FR&EFR and extending it to support HR too. In this plan the rtp_payload_input_preen() function will produce one more output, a SID flag, and this flag will be passed down as an out-of-band datum like the current rtpmsg_marker_bit() mechanism.

To view, visit change 32968. To unsubscribe, or for help writing mail filters, visit settings.