Allow Early Media for RingBack Tone scenarios

[deruelle]

Allow RestComm to Support configuration of RCML to be called for Early Media scenarios such as RingBackTones

[deruelle]

@gvagenas can you paste the link to the design documents that was created for that ?

[gvagenas]

@deruelle there are no design documents for this issue. We have an email thread with subject "Restcomm early media support for inbound and outbound calls" with comments and suggestions from the team.

[gvagenas]

Also related issue is #936

[deruelle]

@gvagenas can you paste the result of the discussion or the status of where we stood in terms of decisions here ?

[gvagenas]

@deruelle the results of the brainstorming was the following:

For outgoing calls, Restcomm will send the INVITE and will receive 183 Session Progress with SDP. In that case we should refactor the Call actor FSM to setup and open the RTP stream to the caller.

For Inbound calls RCML for Early Media will support all tags/verbs except <Dial> Example

• INVITE to Restcomm for DID (with either EarlyMedia = true flag OR to have another URL - Early Media URL- in addition to current Voice URL)
• Restcomm sends 100, 180
• Since this is an EarlyMedia DID, Restcomm downloads RCML and sends 183 Session Progress with SDP Restcomm executes the RCML in the Early Media session
• At the end of RCML :
  • if there is REDIRECT send 200 OK and execute the RCML
  • if RCML reaches the end, hangup the call.

[zeeshan-ks]

Hi @deruelle Flow diagram we made for RBT flow.

Following are the points we will be catering:

• we have to send extra parameter (flag or URI) in initial INVITE for early media
• When Called party sends back 183/180. Restcomm will play RBT to caller
• When caller receive prack ack (200) from restcomm, RBT should end

Do we have any document for restcomm call flow along with diagram so we can update it accordingly?

Kindly confirm if above flow is good to go?

Thanks

[deruelle]

hi @zeeshan-ks

we have to send extra parameter (flag or URI) in initial INVITE for early media

Can you describe what you mean and have in mind for that ?

When Called party sends back 183/180. Restcomm will play RBT to caller

Only for 183 not 180

When caller receive prack ack (200) from restcomm, RBT should end

I would suggest not to use PRACK in the first iteration to make the implementation simpler and end the RBT when 200 OK to INVITE is received.

@gvagenas can provide diagrams location

[shoaib-ks]

The current SIP flow when you dial the 1234 demo application (i.e. inbound call) is:

What is required will be:

correct?

[deruelle]

Hi @shoaib-ks

Sorry for the late reply, I'm not sure why there is 2 200 OK and 2 ACK in your diagram. This http://www.gl.com/images/Newsletter/Newsletter_Packetools_PacketGen_RPR.jpg is the flow that should happen

[shoaib-ks]

Hi @deruelle, thanks for the reply, the image that you shared has 2 200 OK as well. I am also not sure why there are 2 OKs

[deruelle]

@shoaib-ks in this case it's clear the first OK is for PRACK and the second OK is for INVITE. but in your diagram I didn't see any PRACK

[Peter-eid]

Hi @deruelle,

Please could you update me on the current status of this issue ?

[nachkar]

Any news regarding this issue ?