4 ms·

An "UDP" server for browser clients: https://github.com/seemk/WebUDP https://github.com/seemk/WebUDP

by lxtx 9y ago

gfysfm 9y ago
Cool, thanks. I'll try this out if I ever want to switch to WebRTC.
emj 9y ago
I get 60ms RTT for the largest bin of packets with WebUDP many requests goes as high as 140ms (positive skew of the distribution), while ICMP never goes above 29ms RTT. I know UDP can be badly prioritized in some networks but I don't think it can only be that... This needs more investigations imho, I wonder where this fails so badly; is WebRTC aiming at ~100ms latency?
- lxtx 9y ago
  Definitely a bit weird. Where are you located? The echo demo server is hosted in the Netherlands. That's how the round trip histogram looks for me in Estonia: https://i.imgur.com/iBoqwe4.png https://i.imgur.com/iBoqwe4.png I'll take a look later if there's any noticeable delays caused by the server.
  - emj 9y ago
    I left it running for some hours and got alot more 30ms responses: https://imgur.com/a/SdWtc https://imgur.com/a/SdWtc
    - emj 9y ago
      Chrome use ~100% cpu transceiving ~83 packets per second, and I think it sends packets at a slower rate later on, that's why we get so many 30ms responses when we wait some hours. This is a tcpdump after loading the page: \time sudo tcpdump -c 1000 -ni eth0 udp and port 9777 1000 packets captured 1000 packets received by filter 0 packets dropped by kernel 0.02user 0.05system 0:12.45elapsed 0%CPU (0avgtext+0avgdata 5472maxresident)k 0inputs+8outputs (0major+1508minor)pagefaults 0swaps This is just a flood ping, interesting that the UDP version shoots more packets. \time sudo ping -f -c 1000 188.166.46.128 PING 188.166.46.128 (188.166.46.128) 56(84) bytes of data. .... --- 188.166.46.128 ping statistics --- 1000 packets transmitted, 996 received, 0% packet loss, time 14195ms rtt min/avg/max/mdev = 28.839/38.641/50.433/5.152 ms, pipe 5, ipg/ewma 14.209/41.787 ms 0.02user 0.13system 0:14.31elapsed 1%CPU (0avgtext+0avgdata 2248maxresident)k 0inputs+8outputs (0major+1183minor)pagefaults 0swaps
  - emj 9y ago
    https://imgur.com/a/9KHYj https://imgur.com/a/9KHYj this is after start up.

An "UDP" server for browser clients: https://github.com/seemk/WebUDP https://github.com/seemk/WebUDP

by lxtx 9y ago

An "UDP" server for browser clients: https://github.com/seemk/WebUDP https://github.com/seemk/WebUDP

gfysfm 9y ago

Cool, thanks. I'll try this out if I ever want to switch to WebRTC.

emj 9y ago

I get 60ms RTT for the largest bin of packets with WebUDP many requests goes as high as 140ms (positive skew of the distribution), while ICMP never goes above 29ms RTT. I know UDP can be badly prioritized in some networks but I don't think it can only be that... This needs more investigations imho, I wonder where this fails so badly; is WebRTC aiming at ~100ms latency?

lxtx 9y ago
Definitely a bit weird. Where are you located? The echo demo server is hosted in the Netherlands. That's how the round trip histogram looks for me in Estonia: https://i.imgur.com/iBoqwe4.png https://i.imgur.com/iBoqwe4.png I'll take a look later if there's any noticeable delays caused by the server.
- emj 9y ago
  I left it running for some hours and got alot more 30ms responses: https://imgur.com/a/SdWtc https://imgur.com/a/SdWtc
  - emj 9y ago
    Chrome use ~100% cpu transceiving ~83 packets per second, and I think it sends packets at a slower rate later on, that's why we get so many 30ms responses when we wait some hours. This is a tcpdump after loading the page: \time sudo tcpdump -c 1000 -ni eth0 udp and port 9777 1000 packets captured 1000 packets received by filter 0 packets dropped by kernel 0.02user 0.05system 0:12.45elapsed 0%CPU (0avgtext+0avgdata 5472maxresident)k 0inputs+8outputs (0major+1508minor)pagefaults 0swaps This is just a flood ping, interesting that the UDP version shoots more packets. \time sudo ping -f -c 1000 188.166.46.128 PING 188.166.46.128 (188.166.46.128) 56(84) bytes of data. .... --- 188.166.46.128 ping statistics --- 1000 packets transmitted, 996 received, 0% packet loss, time 14195ms rtt min/avg/max/mdev = 28.839/38.641/50.433/5.152 ms, pipe 5, ipg/ewma 14.209/41.787 ms 0.02user 0.13system 0:14.31elapsed 1%CPU (0avgtext+0avgdata 2248maxresident)k 0inputs+8outputs (0major+1183minor)pagefaults 0swaps
- emj 9y ago
  https://imgur.com/a/9KHYj https://imgur.com/a/9KHYj this is after start up.