thank you for you quick reply

these devices are sip pbx kind-of-do-it-all (sip, dect, isdn, analog ...)
see also http://www.aastra.com/cps/rde/xchg/04/hs.xsl/15668.htm

i also posted a call setup done right now with ignore_display_updates=true and i
see no difference - please note the many update packages send from our freeswitch (92.63.208.24)
after 200 ok.

http://pastebin.freeswitch.org/11934

br