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.