Context data sending from a UCMA 4.0 application BEFORE the call is answer via Lync Client

Hi all,

I am attempting to make voice call via UCMA 4.0 using :-

.....

call.BeginEstablish("sip:" + dest   + domain, co, handle(onEstablished), () ) |> ignore

The call correctly is seen on Lync Client, and I have an app(Lync SDK) running so events can be see, and the incoming call is seen.

Before the call is answered by the Lync Client, I would like to send context data. ( either caused by the BeginEstablish call ie the INVITE message, or after the call is presented to the Lync Client and is ringing)

http://msdn.microsoft.com/en-us/library/office/jj945536.aspx implies that context data sending is possible before the call is answer. However to send  context data, ConversationContextChannel needs to be created.

I would create ConversationContextChannel  as follows :-

let rp = conversation.RemotePartipants |> ignore

let rpe = rp.GetEndpoints()

let conversationChannel = ConversationContextChannel(conversation, rpe)

However before the call is answered, the conversation.RemotePartipants is not filled in, so I cannot create a ConversationContextChannel.

So is there a way to send context data for a voice call, before the call is answered? or maybe I have miss-read the MSDN link.

Could there be an alternative way to send custom data/text from an UCMA app to Lync Client SDK to pick up, which I have not seen ?  

Sunil Bhanderi