Earlier this week, we posted an email from a frustrated Qwest customer who said he couldn’t download YouTube and other online videos at a speed equivalent to the Qwest service he was paying for. Qwest wrote to us, and spoke to the customer, and swore they were not interfering with any download rates. Instead, it looks like the problem is with OpenDNS, a free service that usually speeds up downloading, but that seems to have an issue when it comes to certain video streams.

First, here are two entries from the OpenDNS forums by a different customer, posted back in March, that describe the problem:

When I use OpenDNS for my DNS servers, YouTube loads videos very slowly (it is actually impossible to watch anything). The second I switch back to my ISP DNS, YouTube videos load fast.

I KNOW OpenDNS is ONLY a DNS server and should not affect my download speeds — BUT IT DOES, at least on YouTube. It does not matter if I use a Mac (10.5.6) or a PC (XP SP3) I get the same results.

Here’s what happens with OpenDNS:

[removed screen movie from server but basically the “loading” spinner in youtube would sit there spinning, then the video would play for 1-2 seconds, then go back to the loading spinner for 20 seconds, then play a couple seconds, etc]

Here’s what happens with my ISP DNS:

[removed screen movie from server but with my ISP DNS the movie loads fine and plays without a problem]

EDIT: Adding youtube.com to my whitelist does nothing.

---

I did some more digging and figured out that the .swf file is appears to be calling a .flv file that is hosted at:

v19.cache.googlevideo.com

When using my ISP DNS, it wants to pull the video from 74.125.165.88 — and the video downloads in about 90 seconds. In fact, the first 1/4th of the video comes in at a whopping 800 KB(ytes)/sec, then it seems it is trottled at the source end down to about 100 KB/sec for the rest (I’m assuming this is how they do it for youtube to keep their bandwidth in check).

When using OpenDNS, it wants to pull the video from 74.125.100.100 — and the video download crawls along and the estimated completion time is 20+ minutes.

(I am downloading just the FLV file separate from the youtube page using my browser’s download manager)

If I manually put this IP in the URL for the .flv (no matter what I have my DNS set to), I get the same results. That is, I can put the “good/fast” IP in the URL and get a fast download even when using OpenDNS servers.

Apparently something is happening where OpenDNS is returning this “bad/slow” IP when looking up v19.cache.l.googlevideo.com

Our own OP performed a similar experiment and says his YouTube streaming is back to normal:

I ran a traceroute to v23.iscache5.googlevideo.com, the apparent server within Google that was serving up the video. I was a bit surprised to see the the traceroute cut off at an OpenDSN router (line 10 in the included traceroute) from my IP to the cited Google server. I have been using OpenDNS’s servers for a a few years with for security reasons. I’ve been more than pleased with their service (free to individuals).

I reconfigured my network’s DNS to point to QWests own nameservers. I again attempted viewing the same video. This time the download completed without stalling or interruption in the display. FlashGot’s instrumentation showed a rate of 60Kbs. A traceroute to the same google video server yielded an entirely different route to the destination. See the included traceroute.

I ran these experiments several times and the results were consistent.

I would imagine that the reason OpenDNS routed traffic via their own IP-space is to identify potential malware and to protect its users from same, a laudable goal, and part of their service. I’ll stay with QWest’s nameservers until QpenDNS investigates my trouble ticket and fixes it or refutes my suspicion.

Did I get it right this time? Time will tell.

Traceroutes follow …
Using opendns’s name servers (208.67.220.220)
traceroute to v23.iscache5.googlevideo.com (208.67.216.132), 30 hops max, 40 byte packets
1 gateway (192.168.1.1) 1.166 ms 1.647 ms 2.089 ms
2 * * *
3 tukw-dsl-gw22-214.tukw.qwest.net (63.231.10.214) 59.107 ms 68.397 ms 68.847 ms
4 tukw-agw1.inet.qwest.net (71.217.184.169) 70.277 ms 70.600 ms 71.929 ms
5 sea-core-01.inet.qwest.net (67.14.1.194) 73.591 ms 73.757 ms 73.912 ms
6 sea-brdr-01.inet.qwest.net (205.171.26.82) 74.155 ms 73.224 ms 75.141 ms
7 POS1-1.BR1.SEA1.ALTER.NET (204.255.174.177) 74.957 ms 54.444 ms 55.264 ms
8 0.so-4-2-0.XT1.SEA1.ALTER.NET (152.63.105.82) 56.941 ms 56.282 ms 57.602 ms
9 195.ATM4-0.GW10.SEA1.ALTER.NET (152.63.104.1) 58.294 ms 56.959 ms 57.516 ms
10 opendns-gw.customer.alter.net (63.65.72.74) 58.111 ms 59.424 ms 59.580 ms
11 * * *
12 * * *
13 * * *
…
30 * * *

Using QWest’s nameservers (205.171.3.65)
1 gateway (192.168.1.1) 0.924 ms 1.327 ms 1.745 ms
2 * * *
3 tukw-dsl-gw22-214.tukw.qwest.net (63.231.10.214) 56.385 ms 57.373 ms 58.440 ms
4 tukw-agw1.inet.qwest.net (71.217.184.169) 60.214 ms 61.207 ms 62.190 ms
5 sea-core-01.inet.qwest.net (67.14.1.194) 63.198 ms 64.190 ms 65.183 ms
6 sea-brdr-01.inet.qwest.net (205.171.26.82) 66.152 ms 66.203 ms 66.916 ms
7 63.146.26.198 (63.146.26.198) 267.621 ms 213.340 ms 213.519 ms
8 sl-gw20-sea-0-0-0.sprintlink.net (144.232.6.8) 54.976 ms 54.198 ms 54.257 ms
9 sl-googl13-199181-0.sprintlink.net (144.224.13.138) 55.146 ms 54.540 ms 54.197 ms
10 209.85.249.32 (209.85.249.32) 107.489 ms 138.085 ms 128.856 ms
11 72.14.233.117 (72.14.233.117) 109.982 ms 108.183 ms 108.998 ms
12 209.85.242.209 (209.85.242.209) 131.685 ms 164.573 ms 137.819 ms
13 72.14.239.95 (72.14.239.95) 218.838 ms 209.426 ms 228.598 ms
14 209.85.251.41 (209.85.251.41) 248.187 ms 210.056 ms 223.112 ms
15 74.125.6.100 (74.125.6.100) 211.362 ms 219.634 ms 211.790 ms

It turns out another Qwest customer, Andrew, wrote to us yesterday to suggest the same solution to the problem:

I had the exact same problem with Qwest and YouTube; I am, I guess you could call “a heavy user”. However, I realized that this began to happen after I used OpenDNS on my router. After I removed OpenDNS, YouTube worked great and every video downloaded very fast.

“Why does OpenDNS make YouTube load slowly?” [OpenDNS Forums]