Hello Neels, i have checked back with pau. A codec list with 0 elekents is indeed permitted. So I will now change this. In osmo-bsc I will then remove the check, so if the config does not permit any codecs the codec list will have 0 elements. However, we could also just interpret the spec differently. If we support 0 codecs the network wouln't be able to support an IP based user plane interface and therefore the codec list does not have to be included. So in fact we found a solution now. I will keep you posted on this. best regards, Philipp -- Philipp Maier <pmaier@sysmocom.de> http://www.sysmocom.de/ ======================================================================= * sysmocom - systems for mobile communications GmbH * Alt-Moabit 93 * 10559 Berlin, Germany * Sitz / Registered office: Berlin, HRB 134158 B * Geschaeftsfuehrer / Managing Director: Harald Welte