We seem to get Plam-B SDP from jitsi server. Tell us the way to get Unified-Plan

We are orignally developing JitsiMeetClient of C#(UWP).
We struggle to establish RTCPeerConnection by using Unified-Plan.
We can get VideoStream via P2P. A littele more to get videoStream via SFU.

Now, When we connect to JitsiServer via Bosh, we receive session-initiate which seem to be Plan-B.
To be exact,mid is described like name=“audio” name=“video” in Jingle-content-attribute

In contrast,when we check Offer SDP og Chrome browser, Mid = 0,1,2 which is completely Unified-Plan
(we see chrome://web-internals/ and we checked the value Chrome set to setRemoteDesciption()

So We have three question as belows:

Q1. Jitsi server change the way of session-initiate depending on the other client? United-Plan to Chrome,but Plan-B to c#Client?
Or,Chrome itself convert session-initiate to Unified-Plan SDP internally?

Q2.How can we configure or behave to get Unified-Plan SDP from Jitsi Server?
for example, any paremeter is configured?
Any idea is helpfull.

What server version are you running? The last few releases default to unified plan already.

Yes. I know current virsion is already supporting unified plan.Because we get unified plan SDP from jitsi server via chrome. our virsion is the almost latert one.

Why we get plan-B SDP from jitsi server via org.webRTC(C# client)?

ourvirsion is as belows

Prosody 0.11.13
jitsi-meet 2.0.6826-1 all WebRTC JavaScript video conferences
jitsi-videobridge2 2.1-607-g153f7e4e-1 all WebRTC compatible Selective Forwarding Unit (SFU)

Lib-jitsi-meet does that job.

Jitsi Meet server components don’t deal with SDP, they speak Jingle (with some custom bits). lib-jitsi-meet converts the Jingle to Unified Plan SDP. So if you’re seeing Plan-B SDP, something on your client side (in C#) is probably converting the Jingle that Jicofo sends, to Plan-B SDP.

Thank you so much. We try to convert by ourselves.