Call attempt from Lync 2013 via VDI HDXRTOP/2.2.100.949 (thin client) ends with "488 Not Acceptable Here (Error processing content)" from VCS side. VCS version is 8.7.3. Review of the VCS diagnostic log show that it receives SDP origin in the form of -
o=sip:someuser@domain.net;opaque=user:epid:W3Yfdiodfio34943ghAA;gruu 1900734779 2 IN IP4 10.11.12.13
and VCS's b2bua service does not likes "sip:someuser..." (Invalid syntax while parsing Session Description Protocol)
In opposite when the usual call from Lync it receive the following origin -
o=- 0 1 IN IP4 10.11.12.13
and continue with that call as normal.