MSC split: is_siemens_bts() in libmsc/gsm_04_08.c / conn->bts vs. lchan->ts->trx->bts

I'm trying to get rid of all BTS backpointers in libmsc. In libmsc/gsm_04_08.c, in gsm48_rx_mm_serv_req(), I find: if (is_siemens_bts(bts)) send_siemens_mrpci(msg->lchan, classmark2-1); My conclusion so far is that this "hook" should move to the BSC code, but I could use some comforting approval by more apt contenders... Some detail: send_siemens_mrpci() is found in libbsc/gsm_04_08_utils.c: int send_siemens_mrpci(struct gsm_lchan *lchan, uint8_t *classmark2_lv) { struct rsl_mrpci mrpci; if (classmark2_lv[0] < 2) return -EINVAL; mrpci.power_class = classmark2_lv[1] & 0x7; mrpci.vgcs_capable = classmark2_lv[2] & (1 << 1); mrpci.vbs_capable = classmark2_lv[2] & (1 <<2); mrpci.gsm_phase = (classmark2_lv[1]) >> 5 & 0x3; return rsl_siemens_mrpci(lchan, &mrpci); } IIUC the Siemens BS11 BTS needs to be tickled with a vendor-specific RSL message as soon as a CM service request (GSM48_MT_MM_CM_SERV_REQ) or a paging response is received from a subscriber. Only the BSC knows which BTS is involved, so I'd try to find some place in libbsc/ or osmo-bsc/ to move this away to. The same function is called from gsm48_handle_paging_resp() in libbsc. Any shortcuts / workarounds or could this also be dropped entirely? It does look like that particular case is indeed missing from osmo-bsc. Who is this Mister PCI anyway? ;) The gsm48_handle_paging_resp() function leads me to another, more general question: often, there are two bts pointers around, namely the gsm_subscriber_connection->bts as well as the lchan->ts->trx->bts Are these typically/always/never expected to be the same bts struct? (In this function, both bts pointers are used, and I'd like to understand why.) Thanks! ~Neels -- - Neels Hofmeyr &lt;nhofmeyr(a)sysmocom.de&gt; http://www.sysmocom.de/ ======================================================================= * sysmocom - systems for mobile communications GmbH * Alt-Moabit 93 * 10559 Berlin, Germany * Sitz / Registered office: Berlin, HRB 134158 B * Geschäftsführer / Managing Directors: Holger Freyther, Harald Welte