Dear Colleagues,
We have built a heterogeneous UC infrastructure based on Lync Server 2013 and CUCM 9.1.2.11900-12 and we experienced, that with media bypass, we cant hold the calls on Lync side. I checked the SIP logs on both sides and I saw, when Lync sends a re-invite, CUCM responds with 200 OK and in this there is a parameter "b=CT:64" and unfortunately the Lync could not handle it.
After some investigation I found this link: http://johnacook.wordpress.com/2014/03/27/the-case-of-the-curious-sdp-with-lync-call-manager-media-bypass-and-call-hold-and-resume/
In the post, the author mentioned a LUA script:
M = {} function M.outbound_ANY(msg) local sdp = msg:getSdp() if sdp then local b_CT_line = sdp:getLine(“b=CT”,”64″) if b_CT_line then b_CT_line = b_CT_line:gsub(“64″, “1000”) sdp = sdp:modifyLine(“b=CT”, “64”, b_CT_line) msg:setSdp(sdp) end end end function M.outbound_ANY_ANY(msg) local sdp = msg:getSdp() if sdp then local b_CT_line = sdp:getLine(“b=CT”,”64″) if b_CT_line then b_CT_line = b_CT_line:gsub(“64″, “1000”) sdp = sdp:modifyLine(“b=CT”, “64”, b_CT_line) msg:setSdp(sdp) end end end
return M
I have created a SIP normalization script and afterwards I have assigned it to the SIP trunk but unfortunately the problem still exists.
Do I have to do anything else? Did I miss something?
Thanks,
Laci
