I am experiencing what appear to be packet loss/prioritization issues around http/https traffic when QoS is enabled on my D-Link DIR-655, which I’ve enabled to help with voice quality on my VOIP. VOIP works well, but even when I’m not using the line, HTML pages will fail to load completely, images will get truncated or only partially displayed, and sometimes the page is garbled (this occurs both in Firefox and Chrome). Additionally, Outlook (which connects via https) also has issues staying connected. I do not see these issues when QoS is not enabled and, interestingly, when connected over VPN. My assumption is that there is some issue with how d-link router is processes or prioritizing HTTP and HTTPS traffic. Connectivity. By manually reducing the uplink in the router, I can mitigate the issue. With auto set enabled, it measures an upload speed of 347 kbps (every time). This isn’t hugely inconsistent with the net speed tests I run and usually these come in slightly lower than the measured uplink value. Also, when I manually set the value, the speed test tend to track to about 40kbps below the specified value. Again, the lower value of uplink speed I use, the more the stable the system seems to be.
I’ve tried to mitigate as many extraneous factors as possible. I recently upgrade my DSL modem to a 2wire 2701HG-B. I’ve contacted AT&T and they’ve made some adjustments on their end of the line, providing increased both upload and download performance as measure via speakeasy. I’m seeing just under 3Mbps download speeds and over 300 kbps upload speeds without QoS enabled. http://www.voipreview.org/voipspeedtester.aspx provides differing download speed results at a lower 2.32 Mbps but similar upload speeds of 205kps … the following are the results from my test with uplink speed manually set to 245kpbs.
Speed test statistics
---------------------
Download speed: 1339472 bps
Upload speed: 205264 bps
Download quality of service: 33 %
Upload quality of service: 91 %
Download test type: socket
Upload test type: socket
Maximum TCP delay: 850 ms
Average download pause: 23 ms
Minimum round trip time to server: 98 ms
Average round trip time to server: 116 ms
Estimated download bandwidth: 2480000bps
Route concurrency: 1.8514758
Download TCP forced idle: 0 %
Maximum route speed: 5349792bps
I'm running out of ideas. Any thoughts?