Video streaming appear so late(on streaming plugin)

General
1

Hello, I’m new and need some help. i wonder is it normal to using streaming plugin.
Let’s explain my case, I have an android app( = video publisher ) and an Vue.js for web(= Viewer).
just right after click the button on web page, create room and request to publish video to android app( it means attach janus and get session handle(=streaming plugin) and publish video.)
Everythings alright, but, right after click the button on web it take roughly 4~6 seconds before appearing video. Is it normal time duration?
how can i reduce appering time video? I can’t increase biterate on android-app…

Just let you know more additional info for help
I made a streaming room like thiis

}
 {
    "janus": "message",
    "transaction": "rtcManagement",
    "body": {
        "request": "create",
        "name": "room-name",
        "description": "desc",
        "id": "1868",
        "pin": "2368",
        "type": "rtp",
        "video": true,
        "videopt": 96,
        "videoport": 27694,
        "videofmtp": "profile-level-id\u003d42e01f;packetization-mode\u003d1",
        "videortpmap": "H264/90000",
        "videobufferkf": true,
    }
}

SDPs..
o=- 1702430723228661 1 IN IP4 {ip}
s=Mountpoint 1868
t=0 0
a=group:BUNDLE video
a=extmap-allow-mixed
a=msid-semantic: WMS janus
m=video 9 UDP/TLS/RTP/SAVPF 96 97
c=IN IP4 {ip}
a=send only
a=mid:video
a=rtcp-mux
a=ice-ufrag:1n6K
a=ice-pwd:EK3lb/41HonkC7ek9fHxH1
a=ice-options:trickle
a=fingerprint:sha-256 4E:9C:E0:6A:03:E7:F1:B8:A7:CC:00:E7:1E:95:30:24:39:EB:C0:6B:CA:AA:47:11:19:1D:0B:EF:FE:77:A1:36
a=setup:actpass
a=rtpmap:96 H264/90000
a=fmtp:96 profile-level-id=42e01f;packetization-mode=1
a=rtcp-fb:96 nack
a=rtcp-fb:96 nack pli
a=rtcp-fb:96 goog-remb
a=extmap:1 urn:ietf:params:rtp-hdrext:sdes:mid
a=extmap:2 http://www.webrtc.org/experiments/rtp-hdrext/abs-send-time
a=rtpmap:97 rtx/90000
a=fmtp:97 apt=96
a=ssrc-group:FID 4225096029 2295251847
a=msid:janus janusv0
a=src:4225096029 cname:janus
a=ssrc:4225096029 msid:janus janusv0
a=ssrc:4225096029 mslabel:janus
a=ssrc:4225096029 label:janusv0
a=ssrc:2295251847 cname:janus
a=ssrc:2295251847 msid:janus janusv0
a=ssrc:2295251847 mslabel:janus
a=ssrc:2295251847 label:janusv0
a=candidate:1 1 udp 2015363327 {ip} 22617 typ host
a=end-of-candidates


Remote SDP
v=0
o=- 5949535481237753075 2 IN IP4 127.0.0.1
s=-
t=0 0
a=group:BUNDLE video
a=extmap-allow-mixed
a=msid-semantic: WMS
m=video 9 UDP/TLS/RTP/SAVPF 96 97
c=IN IP4 0.0.0.0
a=rtcp:9 IN IP4 0.0.0.0
a=ice-ufrag:nOE4
a=ice-pwd:SbUYi1Gt0jzDcqv589RHaUhn
a=ice-options:trickle
a=fingerprint:sha-256 DA:4E:74:CC:C8:86:D2:35:E5:48:5A:BF:6B:C3:A3:9E:48:73:3D:BD:38:6E:A5:CC:7B:F4:2F:63:A3:92:F5:36
a=setup:active
a=mid:video
a=extmap:2 http://www.webrtc.org/experiments/rtp-hdrext/abs-send-time
a=extmap:1 urn:ietf:params:rtp-hdrext:sdes:mid
a=recvonly
a=rtcp-mux
a=rtpmap:96 H264/90000
a=rtcp-fb:96 goog-remb
a=rtcp-fb:96 nack
a=rtcp-fb:96 nack pli
a=fmtp:96 level-asymmetry-allowed=1;packetization-mode=1;profile-level-id=42e01f
a=rtpmap:97 rtx/90000
a=fmtp:97 apt=96
2

Viewers will only see something when the first keyframe arrives, which may happen later if they connect in between keyframes. If the source of media is the VideoRoom, configure forwarders and Streaming plugin to exchange RTCP info. If the source is an external application, nothing you can do except maybe increase the frequency of keyframes to decrease the maximum wait time (but not too much or it will work like crap).