Hey Osmocom,

I am working to test hrAMR codec with osmo-bts-oc2g but it doesn't seem the correct TCH/F frame type is being activated:

<0000> ../../../osmo-bts/src/common/rsl.c:2805 (bts=0,trx=0,ts=1,pchan=TCH/F_TCH/H_PDCH as PDCH) ss=0 Rx RSL CHAN_ACTIV <0000> ../../../osmo-bts/src/common/amr.c:105 AMR Multirate with 6 modes len=2 not possible <0000> ../../../osmo-bts/src/common/rsl.c:1159 (bts=0,trx=0,ts=1,ss=0): chan_nr=TCH/H(0) on TS1 type=0x01 mode=SPEECH_AMR <0006> ../../../osmo-bts/src/common/l1sap.c:1471 activating channel chan_nr=TCH/H(0) on TS1 trx=0 <0006> ../../../osmo-bts/src/osmo-bts-oc2g/oml.c:937 (bts=0,trx=0,ts=1,ss=0): lchan2lch_par tch_mode=0x41 <0006> ../../../osmo-bts/src/osmo-bts-oc2g/oml.c:1083 (bts=0,trx=0,ts=1,ss=0) MPH-ACTIVATE.req (hL2=0x000100bb, TCH/H TxDL) <0006> ../../../osmo-bts/src/osmo-bts-oc2g/oml.c:822 (bts=0,trx=0,ts=1,ss=0) MPH-ACTIVATE.conf (TCH/H TxDL) <0006> ../../../osmo-bts/src/osmo-bts-oc2g/oml.c:833 Error activating L1 SAPI TCH/H on TS 1: Invalid parameter <0006> ../../../osmo-bts/src/osmo-bts-oc2g/oml.c:1109 (bts=0,trx=0,ts=1,ss=0) act failed mark broken due status: -4 <0006> ../../../osmo-bts/src/common/l1sap.c:623 activate confirm chan_nr=TCH/H(0) on TS1 trx=0 <0000> ../../../osmo-bts/src/common/rsl.c:787 (bts=0,trx=0,ts=1,ss=0): Sending Channel Activated NACK: cause = 0x25

Frame 202: 101 bytes on wire (808 bits), 101 bytes captured (808 bits) on interface 0 Linux cooked capture Internet Protocol Version 4, Src: 10.42.0.1, Dst: 10.42.0.50 Transmission Control Protocol, Src Port: 3003, Dst Port: 51480, Seq: 90, Ack: 206, Len: 33 IPA protocol ip.access, type: RSL Radio Signalling Link (RSL) 0000 100. = Message discriminator: Dedicated Channel Management messages (4) .... ...0 = T bit: Not considered transparent by BTS .010 0001 = Message type: CHANnel ACTIVation (0x21) Channel number IE Activation Type IE Channel Mode IE Channel Identification IE BS Power IE MS Power IE Timing Advance IE MultiRate configuration IE Element identifier: MultiRate Configuration (0x36) Length: 2 001. .... = Multirate speech version: Adaptive Multirate speech version 1 (1) ...0 .... = NSCB: Noise Suppression Control Bit: Noise Suppression can be used (default) (0) .... 1... = ICMI: Initial Codec Mode Indicator: The initial codec mode is defined by the Start Mode field (1) .... ..00 = Start Mode: 0 0... .... = 12,2 kbit/s codec rate: is not part of the subset .0.. .... = 10,2 kbit/s codec rate: is not part of the subset ..1. .... = 7,95 kbit/s codec rate: is part of the subset ...1 .... = 7,40 kbit/s codec rate: is part of the subset .... 1... = 6,70 kbit/s codec rate: is part of the subset .... .1.. = 5,90 kbit/s codec rate: is part of the subset .... ..1. = 5,15 kbit/s codec rate: is part of the subset .... ...1 = 4,75 kbit/s codec rate: is part of the subset

I am trying to understand how codec negotiation is performed, and whether this is a bug or mis-configuration.

I've attached the BTS pcap and configurations that are being used.

Thanks,

Omar