This document was generated from CDN thread
Created by: JAMES DEPHILLIP II on 04-11-2013 12:24:12 PM
Has anyone tried getting screenshots from a 8961/9971 using HTTPS? It always gives back garbled images. I get one out of every five that comes back correctly it seems like. If I switch to HTTP I do not get this problem. I have tried this on many versions of software so it has not been fixed.
Thanks,
Jim
Subject: RE: 8961/9971 HTTPS Screenshot Issues
Replied by: Adrienne Moherek on 04-11-2013 04:51:30 PM
Hi Jim,
With HTTPS I was able to see a garbled image 50% of the time I tested it on the 8961 phone. Let me see if I can open a defect for this.
Thanks,
Adrienne
Subject: RE: 8961/9971 HTTPS Screenshot Issues
Replied by: JAMES DEPHILLIP II on 04-11-2013 05:11:01 PM
Thanks Adrienne!
Subject: RE: 8961/9971 HTTPS Screenshot Issues
Replied by: Adrienne Moherek on 07-11-2013 01:23:54 PM
Hi Jim,
After troubleshooting the issue we were able to determine that it is a network connectivity issue, not a phone issue. When I used Wireshark to capture the packets we noticed a lot of network retransmission. However, when I moved my PC to the same VLAN as the phone, I was not able to reproduce the garbled image and I tried many times.
To prevent this from happening, I'd suggest doing the same.
Thanks,
Adrienne
Subject: RE: 8961/9971 HTTPS Screenshot Issues
Replied by: David Staudt on 07-11-2013 02:15:09 PM
The aggregate symptoms here do make it sound like a possible low-level issue in the phone, perhaps CPU/memory related as handling the rather large image data returned is kind of an unusual task for the device - it would make sense this would be exacerbated by the encryption processing overhead of HTTPS.
If so, probably the best way to find a resolution would be to identify a way to (somewhat reliably) reproduce the issue. If that's simple - e.g. 'browse to the screenshot URI and hit refresh several (dozen) times' we can try to reproduce here...if you find the problem is model/firmware/environment specific then we may need you to enable/retrieve some low-level logs from the phone.
Subject: RE: 8961/9971 HTTPS Screenshot Issues
Replied by: JAMES DEPHILLIP II on 07-11-2013 02:03:42 PM
Adrienne,
This happens a lot in production more so when using HTTPS vs HTTP. I was able to replicate it in my lab a few times. Of course now that I have opened wireshark I can not seem to be able to reproduce the issue. If the issue is only caused when retransmissions occur doesn't that almost imply that the TCP stack is not operating correctly? One thing to note on this was that we had a 9971 doing this yesterday and it corrected itself after a full reset of the phone.
Thanks,
Jim
