Bug #4082
openOML: Unknown/unhandled PCHAN type: 0 NONE
0%
Description
If at least one time-slot in OsmoBSC is configured as NONE:
network ... bts 0 ... trx 0 ... timeslot 0 phys_chan_config CCCH hopping enabled 0 ... timeslot 7 phys_chan_config NONE hopping enabled 0
OsmoBTS fails to start:
... DOML DEBUG oml.c:877 OC=CHANNEL(03) INST=(00,00,06): Rx SET CHAN ATTR DOML INFO oml.c:941 OC=CHANNEL(03) INST=(00,00,06): OC=CHANNEL INST=(00,00,06) SET CHAN ATTR (TSC=7 pchan=TCH/H) DL1C NOTICE scheduler.c:948 Configuring multiframe with TCH/H+SACCH trx=0 ts=6 DOML DEBUG oml.c:454 OC=CHANNEL(03) INST=(00,00,06): Sending FOM ACK. DOML DEBUG oml.c:981 OC=CHANNEL(03) INST=(00,00,06): Rx CHG ADM STATE DOML DEBUG oml.c:144 OC=CHANNEL(03) INST=(00,00,06): Tx Change Administrative State Ack DOML DEBUG oml.c:144 OC=CHANNEL(03) INST=(00,00,06): Tx State Changed Event Report DOML DEBUG oml.c:954 OC=CHANNEL(03) INST=(00,00,06): Rx OPSTART DOML DEBUG oml.c:964 OC=CHANNEL(03) INST=(00,00,06): ... automatic ACK, OP state already was Enabled DOML DEBUG oml.c:144 OC=CHANNEL(03) INST=(00,00,06): Tx Opstart Ack DTRX NOTICE trx_if.c:487 phy0.0: Using legacy TRXD header format version DL1C DEBUG l1_if.c:177 phy0.0: (bts=0,trx=0,ts=6) l1if_setslot_cb(as_pchan=TCH/H), calling cb_ts_connected(rc=0) DOML DEBUG oml.c:877 OC=CHANNEL(03) INST=(00,00,07): Rx SET CHAN ATTR DOML ERROR oml.c:863 Unknown/unhandled PCHAN type: 0 NONE DOML ERROR oml.c:924 OC=CHANNEL(03) INST=(00,00,07): SET CHAN ATTR: invalid Chan Comb 0xff (pchan=NONE, conf_lchans()->-14) DOML NOTICE oml.c:446 OC=CHANNEL(03) INST=(00,00,07): Sending FOM NACK with cause Parameter value outside permitted range. DLINP ERROR input/ipa.c:65 127.0.0.1:3002 connection closed with server DABIS ERROR abis.c:144 Signalling link down DABIS FATAL abis.c:158 OML link was closed early within 1 seconds. If this situation persists, please check your BTS and BSC configuration files for errors. A common error is a mismatch between unit_id configuration parameters of BTS and BSC. DOML NOTICE bts.c:285 Shutting down BTS 0, Reason Abis close DL1C NOTICE scheduler.c:597 Exit scheduler for trx=0 ...
Updated by fixeria over 4 years ago
Here is what I can see from Wireshark:
IPA protocol ip.access, type: OML DataLen: 13 Protocol: OML (0xff) GSM A-bis OML, Radio Channel(00,00,02) Set Channel Attributes Message Discriminator: Formatted O&M (0x80) Placement Indicator: Only (0x80) Sequence Number: 0x00 Length Indicator: 9 FOM Message Type: Set Channel Attributes FOM Object Class: Radio Channel (0x03) FOM Object Instance BTS: 0 FOM Object Instance TRX: 0 FOM Object Instance TS: 2 FOM Attribute ID: Channel Combination FOM Attribute Length: 1 Channel Combination: Unknown (0xff) <----- Is it legal?!? FOM Attribute ID: Training Sequence Code FOM Attribute Length: 1 TSC: 0x07
My best guess is that OsmoBSC should never send any OML messages for disabled timeslots (i.e. set to NONE).
laforge, what do you think? If my guess is correct, I will update the ticket and change project to OsmoBSC.
Updated by laforge over 4 years ago
I Think it is useful to send auch messages, as they could happen at runtime of a bts. What if the TS was previously configured as TCH and now you disable it in the config and restart the oml link. On a BTS that doesn't reboot (like all non-osmobts BTS) you would keep that timeslot in TCH rather than disabling it. In the best case, the behavior of non-osmo bts should be tested. If they support NONE, so should osmobts.