the first completely successful handover (for the public release) is traced here: http://opensigtran.org/20121022_handover_voice.pcap.gz
sources are git-ed at https://github.com/dmisol/openbts-p2.8/commits/handover
It is important to configure Freeswitch properly, setting "rtp-rewrite-timestamps" to "true".
All target-BTS procedures are implemented, while originating-side activities are done as workaround, inside a CLI thread. They will be moved to a dedicated thread (like at the target BTS) asap.
UmTRX cards were used to eliminate the influence of improper clocking. Meanwhile the handsets from Nokia are still not supported.
All mandatory parameters for non-synchronized handover seems to be set properly.. So, real-life traces of non-synchronized handover are welcomed.