UCWA - Accepting an incoming onlineMeetingInvitation - ucwa

Question

Summary
I have a UCWA application and I would like it to accept incoming onlineMeetingInvitation events and then monitor all messages. While I have been able to accept the invitation successfully, I do not receive events for any messages. I believe this may be because the messaging modality is not connected by default, so I am attempting to addMessaging. Unfortunately, this request always returns with a 409 error and the message,
There was a conflict that prevented the operation from starting. Please try again later.
Does anyone know,
a. If attempting to addMessaging is correct?
b. Why I am getting the above error?
Details
I set up have two normal Lync Clients in conversation. I then invite my UCWA application's user into the conversation. This results in the following response on my event channel, (including the accept link as expected)
{
"_links": {
"self": {
"href": "/ucwa/oauth/v1/applications/102547331865/events?ack=28"
},
"next": {
"href": "/ucwa/oauth/v1/applications/102547331865/events?ack=29"
}
},
"sender": [
{
"rel": "me",
"href": "/ucwa/oauth/v1/applications/102547331865/me",
"events": [
{
"link": {
"rel": "presence",
"href": "/ucwa/oauth/v1/applications/102547331865/me/presence"
},
"type": "updated"
}
]
},
{
"rel": "communication",
"href": "/ucwa/oauth/v1/applications/102547331865/communication",
"events": [
{
"link": {
"rel": "onlineMeetingInvitation",
"href": "/ucwa/oauth/v1/applications/102547331865/communication/onlineMeetingInvitations/6cb18668cbda428e839652ae1f6cd58f"
},
"_embedded": {
"onlineMeetingInvitation": {
"direction": "Incoming",
"importance": "Normal",
"threadId": "AdIw2sMaOjuEJHfcRJiiK5Czug+5Ug==",
"state": "Connecting",
"subject": "",
"onlineMeetingUri": "sip:test.user2#xxx.xxx.xx;gruu;opaque=app:conf:focus:id:KS77KG4B",
"availableModalities": [
"Messaging"
],
"_links": {
"self": {
"href": "/ucwa/oauth/v1/applications/102547331865/communication/onlineMeetingInvitations/6cb18668cbda428e839652ae1f6cd58f"
},
"to": {
"href": "/ucwa/oauth/v1/applications/102547331865/people/test.user1#xxx.xxx.xx"
},
"conversation": {
"href": "/ucwa/oauth/v1/applications/102547331865/communication/conversations/3b80d6be-b57c-4cc1-b10d-cd5c89ffa09d"
},
"accept": {
"href": "/ucwa/oauth/v1/applications/102547331865/communication/onlineMeetingInvitations/6cb18668cbda428e839652ae1f6cd58f/accept"
},
"decline": {
"href": "/ucwa/oauth/v1/applications/102547331865/communication/onlineMeetingInvitations/6cb18668cbda428e839652ae1f6cd58f/decline"
}
},
"_embedded": {
"from": { ....
I perform a POST on the 'accept' href which responds succesfully with no content. I then receive 2 event responses, the 2nd of which includes the following
...
{
"rel": "communication",
"href": "/ucwa/oauth/v1/applications/102547331865/communication",
"events": [
{
"link": {
"rel": "conversation",
"href": "/ucwa/oauth/v1/applications/102547331865/communication/conversations/3b80d6be-b57c-4cc1-b10d-cd5c89ffa09d"
},
"_embedded": {
"conversation": {
"state": "Conferenced",
"threadId": "AdIw2sMaOjuEJHfcRJiiK5Czug+5Ug==",
"subject": "",
"activeModalities": [
"Messaging"
],
"importance": "Normal",
"participantCount": 3,
"audienceMute": "Disabled",
"audienceMessaging": "Enabled",
"recording": false,
"_links": {
"self": {
"href": "/ucwa/oauth/v1/applications/102547331865/communication/conversations/3b80d6be-b57c-4cc1-b10d-cd5c89ffa09d"
},
"applicationSharing": {
"href": "/ucwa/oauth/v1/applications/102547331865/communication/conversations/3b80d6be-b57c-4cc1-b10d-cd5c89ffa09d/applicationSharing"
},
"audioVideo": {
"href": "/ucwa/oauth/v1/applications/102547331865/communication/conversations/3b80d6be-b57c-4cc1-b10d-cd5c89ffa09d/audioVideo"
},
"dataCollaboration": {
"href": "/ucwa/oauth/v1/applications/102547331865/communication/conversations/3b80d6be-b57c-4cc1-b10d-cd5c89ffa09d/dataCollaboration"
},
"messaging": {
"href": "/ucwa/oauth/v1/applications/102547331865/communication/conversations/3b80d6be-b57c-4cc1-b10d-cd5c89ffa09d/messaging"
},
"phoneAudio": {
"href": "/ucwa/oauth/v1/applications/102547331865/communication/conversations/3b80d6be-b57c-4cc1-b10d-cd5c89ffa09d/phoneAudio"
},
"localParticipant": {
"href": "/ucwa/oauth/v1/applications/102547331865/communication/conversations/3b80d6be-b57c-4cc1-b10d-cd5c89ffa09d/participants/test.user1#xxx.xxx.xx",
"title": "Test User1"
},
"addParticipant": {
"href": "/ucwa/oauth/v1/applications/102547331865/communication/participantInvitations?conversation=3b80d6be-b57c-4cc1-b10d-cd5c89ffa09d"
},
"leaders": {
"href": "/ucwa/oauth/v1/applications/102547331865/communication/conversations/3b80d6be-b57c-4cc1-b10d-cd5c89ffa09d/participants?filter=leaders"
},
"attendees": {
"href": "/ucwa/oauth/v1/applications/102547331865/communication/conversations/3b80d6be-b57c-4cc1-b10d-cd5c89ffa09d/participants?filter=attendees"
},
"lobby": {
"href": "/ucwa/oauth/v1/applications/102547331865/communication/conversations/3b80d6be-b57c-4cc1-b10d-cd5c89ffa09d/participants?filter=lobby"
},
"onlineMeeting": {
"href": "/ucwa/oauth/v1/applications/102547331865/communication/conversations/3b80d6be-b57c-4cc1-b10d-cd5c89ffa09d/onlineMeeting"
},
"enableAudienceMuteLock": {
"href": "/ucwa/oauth/v1/applications/102547331865/communication/conversations/3b80d6be-b57c-4cc1-b10d-cd5c89ffa09d/enableAudienceMuteLock"
},
"disableAudienceMessaging": {
"href": "/ucwa/oauth/v1/applications/102547331865/communication/conversations/3b80d6be-b57c-4cc1-b10d-cd5c89ffa09d/disableAudienceMessaging"
}
},
"rel": "conversation"
}
},
"type": "updated"
}
]
},
...
{
"link": {
"rel": "messaging",
"href": "/ucwa/oauth/v1/applications/102547331865/communication/conversations/3b80d6be-b57c-4cc1-b10d-cd5c89ffa09d/messaging"
},
"_embedded": {
"messaging": {
"state": "Disconnected",
"_links": {
"self": {
"href": "/ucwa/oauth/v1/applications/102547331865/communication/conversations/3b80d6be-b57c-4cc1-b10d-cd5c89ffa09d/messaging"
},
"conversation": {
"href": "/ucwa/oauth/v1/applications/102547331865/communication/conversations/3b80d6be-b57c-4cc1-b10d-cd5c89ffa09d"
},
"addMessaging": {
"href": "/ucwa/oauth/v1/applications/102547331865/communication/messagingInvitations?conversation=3b80d6be-b57c-4cc1-b10d-cd5c89ffa09d"
}
},
"rel": "messaging"
}
},
"type": "updated"
},
...
Again, I believe this is as expected and at this point the original Lync Clients are showing 3 participants as expected.
Next I try to do a POST to the addMessaging href in the above snippet. The POST has no body.
URI : https://xxx.xxx.xx/ucwa/oauth/v1/applications/102547331865/communication/messagingInvitations?conversation=0ae942e4-9133-4888-a0fb-8a7b182fff00
Method : POST
Headers : {Accept=[text/plain, application/json, application/*+json, */*], Content-Length=[0]}
Request body:
The result is a 409 Conflict, and at no point do I receive events for new messages added to the conversation by the two Lync clients.
Header {Cache-Control=[no-cache], Pragma=[no-cache], Via=[1.1 DEVLYNC2.xxx.xxx.xx RtcInt], Content-Length=[120], Content-Type=[application/json], Expires=[-1], Server=[Microsoft-IIS/7.5], X-MS-Server-Fqdn=[DEVLYNC2.xxx.xx.xx], X-AspNet-Version=[4.0.30319], Strict-Transport-Security=[max-age=31536000; includeSubDomains], X-Powered-By=[ASP.NET], Date=[Fri, 28 Oct 2016 07:31:51 GMT]}
Body {"code":"Conflict","message":"There was a conflict that prevented the operation from starting. Please try again later."}

Answer 1

your problem seems solved by adding the operationId, even though it was mentioned as optional in the UCWA documentation.
The root cause is probably that there is a reproducable bug in the display of the microsoft documentation about UCWA : for example https://ucwa.skype.com/documentation/resources-startmessaging the dropdown list to select the version of the API is not visible.
This bug happens only with Mozilla Firefox and I see in your logs that it is the version you are using (nb : I tested with version 61).
With Chrome it displays correctly and you can see that the operationID is sometimes mandatory (on some versions of the API only).
The version of the API used by your server can be determined from this link :
https://learn.microsoft.com/en-us/skype-sdk/ucwa/versioning
I hope this can help you to solve further problems with UCWA - without the need to use the trial-and-error method.