RTP video jitter and packet loss issue based on odd network state
I am a beginner software developer who develops SIP / RTP Voip software. Of course I am using UDP and Video Codec protocol for this H264 video.
Since I am new to this Voip field, I am so confused and suffering from network issues.
I would like to ask the experts about what is network related specifically to address RTP / RTCP problems on Jitter / Packet loss.
After SIP successfully creates a media session, I get some issue for QoS.
The problems I am facing are just below.
Wifi network (latency: download speed 11.1m / s: download speed 14.9Mbps: 3.27Mbps):
http://www.youtube.com/watch?v=epm01c6IT5Q&feature=youtu.be
3G network (latency: 26.4 Mbps Upload speed: 1.94 Mbps upload speed: 2.42 Mbps): http://www.youtube.com/watch?v=-iG156_wdQE&feature=youtu. be
as you can see, over 3G, which has low downloads and uploads and inconsistent latency, the video quality including color green and video recording is better than Wi-Fi.
using a 3G network slower than Wi-Fi I can always use the UI better than Wi-Fi.
I haven't parsed RTP / RTCP packets deeply, but I can tell ...
In a problematic situation where Wi-fi was used for an application, the Jitter was oddly high enough and the packet loss was clearly high as well.
Summarizing,
- As you can see, the video quality is better when I use a slower 3G network than Wi-Fi.
- When Wifi is working there, Jitter and packet loss are obviously high as I can parse the packet with the wired shark on the receiver side.
- That morning, the video problem (green video pixel, video lag) was much more severe, but over time, day and night, the problem recovered slightly.
As far as I know this will be related to network bandwidth and network congestion. I am not sure if this is the correct diagnosis and this problem needs to be addressed as well. I wish I had enough information yet.
Thank.
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You will need to look at the RTCP or RTCP-XR messages to see what is going wrong. If that fails, then like the other posts, you will need to use wireshark to determine what the problem is.
Most likely the network layer issue causing this is doing its best to test your connection to the other side. Traceroute might be a good place to start understanding the difference between 3G routes versus Wi-Fi.
Wi-Fi can have a lot of jitter and packet loss issues that can be related to your cellular network depending on signal strength (and other things). If you can test with a hard wired connection, you can rule out Wi-Fi as an issue, and if you still have problems it should be network / ISP related. If a wired connection solves your problems, you know it's Wi-Fi and you can troubleshoot accordingly.
Green is most likely a jitter / packet loss artifact. Typically in the United States, a ptime of 20 ms is used for voice. This means that audio packets (and video, if used) are sent every 0.02 seconds. If your jitter is higher than 20ms, or you have a high burst or burst burst, you will most likely see and hear jitter because the packets either fail or are dropped or lost. The green screen is just one of many that you may see depending on the application you are using. I work mostly with sound, so I regret not being able to be more helpful with the exact value of this artifact.
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