diff options
Diffstat (limited to 'src/osmo-bsc/codec_pref.c')
| -rw-r--r-- | src/osmo-bsc/codec_pref.c | 85 |
1 files changed, 56 insertions, 29 deletions
diff --git a/src/osmo-bsc/codec_pref.c b/src/osmo-bsc/codec_pref.c index a94d6a834..412ed9afd 100644 --- a/src/osmo-bsc/codec_pref.c +++ b/src/osmo-bsc/codec_pref.c @@ -264,6 +264,47 @@ static uint16_t gen_bss_supported_amr_s15_s0(const struct bsc_msc_data *msc, con return amr_s15_s0_bts & amr_s15_s0_msc; } +/* Special handling for AMR rate configuration bits (S15-S0) */ +static int match_amr_s15_s0(struct channel_mode_and_rate *ch_mode_rate, const struct bsc_msc_data *msc, const struct gsm_bts *bts, const struct gsm0808_speech_codec *sc_match, uint8_t perm_spch) +{ + uint16_t amr_s15_s0_supported; + + /* Normally the MSC should never try to advertise an AMR codec + * configuration that we did not previously advertised as supported. + * However, to ensure that no unsupported AMR codec configuration + * enters the further processing steps we again lookup what we support + * and generate an intersection. All further processing is then done + * with this intersection result. At the same time we will make sure + * that the intersection contains at least one rate setting. */ + + amr_s15_s0_supported = gen_bss_supported_amr_s15_s0(msc, bts, (perm_spch == GSM0808_PERM_HR3)); + + /* NOTE: The sc_match pointer points to a speech codec from the speech + * codec list that has been communicated with the ASSIGNMENT COMMAND. + * However, only AoIP based networks will include a speech codec list + * into the ASSIGNMENT COMMAND. For non AoIP based networks, no speech + * codec (sc_match) will be available, so we will fully rely on the + * local configuration for thoses cases. */ + if (sc_match) + ch_mode_rate->s15_s0 = sc_match->cfg & amr_s15_s0_supported; + else + ch_mode_rate->s15_s0 = amr_s15_s0_supported; + + /* Prefer "Config-NB-Code = 1" (S1) over all other AMR rates setttings. + * When S1 is set, the active set will automatically include 12.2k, 7.4k, + * 5.9k, 4.75k, in case of HR 12,2k is left out. */ + if (ch_mode_rate->s15_s0 & GSM0808_SC_CFG_AMR_4_75_5_90_7_40_12_20) { + ch_mode_rate->s15_s0 &= 0xff00; + ch_mode_rate->s15_s0 |= GSM0808_SC_CFG_AMR_4_75_5_90_7_40_12_20; + } + + /* Make sure at least one rate is set. */ + if ((ch_mode_rate->s15_s0 & 0x00ff) == 0x0000) + return -EINVAL; + + return 0; +} + /*! Match the codec preferences from local config with a received codec preferences IEs received from the * MSC and the BTS' codec configuration. * \param[out] ch_mode_rate resulting codec and rate information @@ -283,7 +324,6 @@ int match_codec_pref(struct channel_mode_and_rate *ch_mode_rate, uint8_t perm_spch; bool match = false; const struct gsm0808_speech_codec *sc_match = NULL; - uint16_t amr_s15_s0_supported; int rc; /* Note: Normally the MSC should never try to advertise a codec that @@ -313,10 +353,22 @@ int match_codec_pref(struct channel_mode_and_rate *ch_mode_rate, /* Match the permitted speech value against the codec lists that were * advertised by the MS and the MSC */ - if (test_codec_pref(&sc_match, scl, ct, perm_spch)) { - match = true; - break; + if (!test_codec_pref(&sc_match, scl, ct, perm_spch)) { + continue; } + + /* Special handling for AMR */ + if (perm_spch == GSM0808_PERM_HR3 || perm_spch == GSM0808_PERM_FR3) { + rc = match_amr_s15_s0(ch_mode_rate, msc, bts, sc_match, perm_spch); + if (rc < 0) { + ch_mode_rate->s15_s0 = 0; + continue; + } + } else + ch_mode_rate->s15_s0 = 0; + + match = true; + break; } /* Exit without result, in case no match can be deteched */ @@ -330,31 +382,6 @@ int match_codec_pref(struct channel_mode_and_rate *ch_mode_rate, /* Lookup a channel mode for the selected codec */ ch_mode_rate->chan_mode = gsm88_to_chan_mode(perm_spch); - /* Special handling for AMR */ - if (perm_spch == GSM0808_PERM_HR3 || perm_spch == GSM0808_PERM_FR3) { - /* Normally the MSC should never try to advertise an AMR codec - * configuration that we did not previously advertise as - * supported. However, to ensure that no unsupported AMR codec - * configuration enters the further processing steps we again - * lookup what we support and generate an intersection. All - * further processing is then done with this intersection - * result */ - amr_s15_s0_supported = gen_bss_supported_amr_s15_s0(msc, bts, (perm_spch == GSM0808_PERM_HR3)); - if (sc_match) - ch_mode_rate->s15_s0 = sc_match->cfg & amr_s15_s0_supported; - else - ch_mode_rate->s15_s0 = amr_s15_s0_supported; - - /* NOTE: The function test_codec_pref() will populate the - * sc_match pointer from the searched speech codec list. For - * AoIP based networks, no speech codec list will be present - * and therefore no sc_match will be populated. For those - * cases only the local configuration will influence s15_s0. - * However s15_s0 is always populated with a meaningful value, - * regardless if AoIP is in use or not. */ - } else - ch_mode_rate->s15_s0 = 0; - return 0; } |