NanoBTS unable to connect to BSC

Hi all, I have an ip.access NanoBTS 139U (Part No 139U V 139U V351800). I believe it is operating on the 1800 MHz although admittedly that's a guess from the part number. I've not found a definitive way of confirming the supported band via Telnet or otherwise. I can see the BTS attempting to connect to the BSC, but after the "Set Radio Carrier Attributes" request from the BSC, the BTS sends a NACK and the OML link is dropped. <0004> abis_nm.c:984 OC=RADIO-CARRIER(02) INST=(00,00,ff): SET RADIO ATTRIBUTE NACK CAUSE=Message cannot be performed <0004> osmo_bsc_main.c:226 Got SET RADIO ATTRIBUTE NACK going to drop the OML links. I've grabbed some debug info, note that in the PCAP the packets are wrapped in TZSP as I used a Mikrotik to stream them to Wireshark. Log from BSC - https://s3.eu-west-2.amazonaws.com/cdn.marrold.co.uk/files/osmocom/osmobsc_… PCAP - https://s3.eu-west-2.amazonaws.com/cdn.marrold.co.uk/files/osmocom/NanoBTS.… It's worth noting that ipaccess-config tool also has an issue parsing the frequency which may well be related: ipaccess-config -G 10.0.130.101 ipaccess-config (C) 2009-2010 by Harald Welte and others This is FREE SOFTWARE with ABSOLUTELY NO WARRANTY Trying to connect to ip.access BTS 10.0.130.101... OML link established using TRX 0 getting Attributes (3): 88 91 86 rc"" 0 <0004> abis_nm.c:652 OC=BASEBAND-TRANSCEIVER(04) INST=(00,00,ff): Get Attributes Response: Primary OML IP is 10.0.130.111:0 <0004> abis_nm.c:658 OC=BASEBAND-TRANSCEIVER(04) INST=(00,00,ff): Get Attributes Response: Unit ID is 1800/0/0 <0004> bts.c:497 (bts=0) Unsupported frequency band. <0007> abis_nm.c:725 (bts=0) BTS config invalid, dropping BTS! <0007> bts_ipaccess_nanobts.c:624 (bts=0) Deferring Drop of OML link. <0007> input/ipaccess.c:431 Bad signalling message, sign_link returned error: Invalid argument. <0007> bts_ipaccess_nanobts.c:557 (bts=0) Dropping OML link: Deferred link drop Thanks in advance Matthew / marrold