8 Replies Latest reply on Jan 23, 2015 8:47 AM by _Maxim_

    WiFi Latency

    johnfron

      I was able to get the wifi configured.But I have severe latency on the network connection 1-7 second ping times, and great lag over an SSH connection. I had to add wpa_supplicant to the system startup, as the connection was not resuming on reboot. I used the commands:

       

      systemctl enable wpa_supplicant

      systemctl start wpa_supplicant

       

      Any thoughts I how I can diagnose the latency issue? I have several other devices on the same network without an issue. (My primary AP is an Apple Airport TimeCapsule).

       

      Thanks in advance for any help!

        • 1. Re: WiFi Latency
          avirtuos

          I can't yet offer you a solution but what I can do is help validate what you are seeing.

           

          Below are some sample ping times for my edison on wifi (802.11n network). Other wireless devices in the house don't exceed ping times of < 10ms (which is isn't great either but not as bad as half a second).  I can also confirm that this at least for me, is attributing to nearly unusable ssh performance. So +1, intel gods please provide us with some insight or let us know you guys are ware of this and working on it. I've also seen it affect performance of Zeromq.

           

          64 bytes from 192.168.1.111: icmp_seq=69 ttl=64 time=363.817 ms

          64 bytes from 192.168.1.111: icmp_seq=70 ttl=64 time=173.487 ms

          64 bytes from 192.168.1.111: icmp_seq=71 ttl=64 time=102.567 ms

          64 bytes from 192.168.1.111: icmp_seq=72 ttl=64 time=432.544 ms

          64 bytes from 192.168.1.111: icmp_seq=73 ttl=64 time=14.604 ms

          64 bytes from 192.168.1.111: icmp_seq=74 ttl=64 time=169.812 ms

          64 bytes from 192.168.1.111: icmp_seq=75 ttl=64 time=88.936 ms

          64 bytes from 192.168.1.111: icmp_seq=76 ttl=64 time=317.778 ms

          64 bytes from 192.168.1.111: icmp_seq=77 ttl=64 time=342.881 ms

          64 bytes from 192.168.1.111: icmp_seq=78 ttl=64 time=155.954 ms

          64 bytes from 192.168.1.111: icmp_seq=79 ttl=64 time=74.970 ms

          64 bytes from 192.168.1.111: icmp_seq=80 ttl=64 time=412.010 ms

          64 bytes from 192.168.1.111: icmp_seq=81 ttl=64 time=332.299 ms

          64 bytes from 192.168.1.111: icmp_seq=82 ttl=64 time=252.837 ms

          64 bytes from 192.168.1.111: icmp_seq=83 ttl=64 time=98.104 ms

          • 2. Re: WiFi Latency
            zankich

            I experience the same exact behavior. When I open another ssh session and continually ping a website from the Edison, I have less latency. No sure if that will help you, but it makes me think it has something to do with an over aggressive power management....

            • 3. Re: WiFi Latency
              johnfron

              I think your theory makes some sense. When I ping from the Edison I get reasonable return times. I had not tried to open another ssh while I was doing that. Hopefully someone will respond with a fix. Without a stable network connection, development is rather difficult.

              • 4. Re: WiFi Latency
                vytronics.com

                Looks like it is some kind of power save optimize setting. I see the same thing and thought maybe the breakout board blocks the antenna. Nope. The wifi is good. While connected over USB run a ping from your edison to your wifi router. While that is going on open up a ssh session and it will run smoothly. I suspect that this might be addressed if you flash the latest firmware and I might try that at some point. However, right now I am a bit afraid of bricking the thing. A work around is to run ping in the background while you go about your business

                 

                Please come back to this thread and share any permanent solutions.

                • 5. Re: WiFi Latency
                  MPayne

                  This does look suspiciously like a power saving setting that I'm familiar with.  I'll ask the FW team to weigh in.

                  • 6. Re: WiFi Latency
                    vytronics.com

                    I loaded the latest image edison-image-ww36-14 and the wifi issue seems to have gone away. I had this issue and know my firmware was quite out of date. Maybe the same for the original poster. I recommend flashing with a current image and try again.

                     

                    Note that I believe there is an issue if you use winzip to unpack the file. Use unzip which if you have githup for windows installed you can run from gitbash. Copy the files to the edison USB drive and then run "reboot ota" as root. FYI, this will wipe out your settings potentially without warning and you will have to re-run the configure_edison script.

                     

                    Cheers.

                    1 of 1 people found this helpful
                    • 7. Re: WiFi Latency
                      rkd

                      It is very important that you are using the latest PV Edison module + Arduino board + edison-image-ww36-14

                      Have not encountered any WIFI latency issues with the WWK36-14 SW, please confirm if you are upto date on the software and still see this issue.

                      • 8. Re: WiFi Latency
                        _Maxim_

                        Edison module + mini breakout board + edison-image-rel1-maint-rel1-ww42-14 problem still exists.