Hello,

I've been having trouble uploading data to the Internet from home over my Qwest ADSL connection.  When trying to upload pictures to Picasa or Shutterfly, or various files via E-Mail, I receive timeout errors.  Only after numerous upload attempts am I ever able to upload my data.  Using Wireshark, I see a tremendous amount of "TCP Dup ACK", "TCP ACKed lost segment", and "TCP retransmission" messages.

I've uploaded my Wireshark logs to:

http://www.cloudshark.org/captures/cc0b35ded00d
http://www.cloudshark.org/captures/a34217c00ffc

According to Wireshark's website:

Quote:

TCP Dup ACK - Occurs when the same ACK number is seen AND it is lower than the last byte of data sent by the sender. If the receiver detects a gap in the sequence numbers, it will generate a duplicate ACK for each subsequent packet it receives on that connection, until the missing packet is successfully received (retransmitted). Clear indication of dropped/missing packets.

TCP Acked lost segment - These are ack's that ethereal can't match with a sent segment. Are ACK that Ethereal detects, but cant see the segment sent.

TCP Retransmission - Occurs when all the data in the packet has been seen in one or more previous packet.

According to Iljitsch van Beijnum (Author of BGP, published by O'Reilly):

Quote:

Upon receiving a duplicate ACK, the sending TCP assumes the unacknowledged data has been lost because of congestion...

Looking at these error messages and their meaning, it looks like I have an OSI layer 3, or higher, problem.  I heard that Qwest does packet shaping.  Perhaps they've miss configured something?  When sending data from work, school, or my neighbor's Internet connection (Comcast), I don't have any problems whatsoever.  I do occasionally see one or more of the error messages listed above, but only one or two, not 50+!

I contacted Qwest's tech support regarding this issue about a month ago.  As tier 1 support, they had me reboot everything, power cycle everything, and then asked that I replace my modem.  I purchased an  Actiontec GT701D from BestBuy for trouble-shooting.  With this new router, I'm experiencing the exact same upload problem.  When none of this fixed my problem, they said that they wouldn't provide me with any more support until I replaced my modem (again) because my modem (Cisco 678) was unsupported (even though it's listed on Qwest's modem support page).

Because my modem is in bridge mode and not participating in any OSI layer 3 or above activities, it's not possible for my modem to be causing these issues.  If I were having an OSI layer 1 or 2 problem, I'd get "Destination Unreachable" errors.

I'm using a Cisco 678 DSL router in bridge mode for my ADSL connection.  Looking at the line quality, I have a good connection.


My download capability is working just fine.  On any given day, I'm pulling down Linux ISOs, patches, games, etc.  As another test, I checked out two Internet speed test websites:

http://denver.speedtest.qwest.net/

Last Result:
Download Speed: 5.793 Mbps (0.7 MB/sec transfer rate)
Upload Speed: 0.718 Mbps (0.1 MB/sec transfer rate)
The closest server located in Denver, CO performed this test with a latency of 38 milliseconds.
Test Date: Sunday, December 05, 2010 9:53:54 AM

http://www.speedtest.net showed almost the same results.

So, it looks like my "speed" is what I expect.  I am getting some "TCP ACTed lost segment" errors during the upload portion of those tests.  I don't think that a lot of data is being pushed up or down during the test, so I'm not having significant enough upload problems for the upload tests to fail or register slow.

I don't believe that calling the support phone number is going to yield any results (based on my last e-mail and voice exchange).  Is there any way to reach Qwest's backline support directly?  Does anyone have any ideas on how to fix this issue?

Thanks,

Rob