jimharle

So I've been testing our office Comcast Business 150/20 recently, and it's been performing adequately. Single-thread TMN downloads I can't get to go above ~108 Mbps for the average, but they do peak at close to 150. We can consistently fill it up with multi-thread downloads, and almost get to 170 (testing our own CDN and other third-party downloads). This is good for us, but alas I don't have room to complain to Comcast about performance. Still, it does indicate that TMN measures various Comcast connections reliably.

Well, corporate people understand spreadsheets, and that is how we initially presented the problems with our last provider...listing ten "known fast" download sites, and how our results compared to other ISPs we had access to. We could always do something similar with participants here, as many TMN "members" use Comcast - come up with a matrix of how your performance differs from others using the same download sites. But then again, that's the whole point of TMN in the first place, and it is unfortunate that they don't take it seriously. Veracity_Testing_with_Traceroutes.zip

Retransmission count? The purpose of the exercise is to see if packet loss is evident; and secondarily, to compare your download rates with "known fast" sources. Even if no packet loss is present, these two tests have already demonstrated that your transfer rates are far slower than they should be. We could do this forever...how many sites does it take to convince Comcast that the real-world downloads are slow? Granted they are also blaming your computer, so another key is demonstrating the slowness using multiple computers, each wired to the cable modem to eliminate any other possibilities. If I were a Comcast tech, that's how I would test it. The key is finding someone who will do it properly. As I mentioned before, our Comcast 150/20 service in our office doesn't seem to be performing as it should (for downloads), and I will have an opportunity to test it tomorrow (straight from the modem with multiple computers, bypassing our local networking equipment). If those tests pan out that something isn't right, I will raise the issue with them, even if they can't replace any cabling or whatnot until Spring. And once a real problem has been established, I will stick to it and keep on them....I won't back down from a technical fight.

So definitely slow, but no perceived packet loss. Let's try something further away for both of us, mirror.flhsi.com [208.65.55.17] in Florida. http://mirror.flhsi.com/centos/7/isos/x86_64/CentOS-7.0-1406-x86_64-NetInstall.iso (same file as the other mirror site). host 208.65.55.17 Tracing route to mirror.flhsi.com [208.65.55.17] over a maximum of 30 hops: 1 <1 ms <1 ms 1 ms firewall.ibsutah.net [192.168.1.1] 2 10 ms 10 ms 9 ms 67.186.246.1 3 9 ms 10 ms 9 ms te-0-6-0-7-sur02.sandy.ut.utah.comcast.net [68.87.220.221] 4 10 ms 10 ms 11 ms te-0-7-0-0-sur01.sandy.ut.utah.comcast.net [69.139.247.17] 5 13 ms 14 ms 14 ms te-0-9-0-0-ar04.saltlakecity.ut.utah.comcast.net [68.87.170.1] 6 26 ms 27 ms 30 ms he-0-2-0-0-cr01.denver.co.ibone.comcast.net [68.86.90.233] 7 23 ms 38 ms 22 ms xe-0-0-2-0-pe01.910fifteenth.co.ibone.comcast.net [68.86.84.26] 8 41 ms 42 ms 41 ms te0-0-0-0.rcr11.b006467-1.den01.atlas.cogentco.com [154.54.10.33] 9 41 ms 41 ms 42 ms te0-6-0-3.ccr21.den01.atlas.cogentco.com [154.54.45.181] 10 43 ms 42 ms 46 ms be2128.ccr21.mci01.atlas.cogentco.com [154.54.25.174] 11 48 ms 47 ms 48 ms be2156.ccr41.ord01.atlas.cogentco.com [154.54.6.86] 12 61 ms 60 ms 66 ms be2098.ccr41.atl01.atlas.cogentco.com [154.54.29.98] 13 68 ms 68 ms 68 ms te0-0-0-0.rcr11.jax01.atlas.cogentco.com [154.54.29.130] 14 75 ms 73 ms 81 ms te3-2.ccr01.mco01.atlas.cogentco.com [154.54.29.138] 15 73 ms 74 ms 74 ms 38.104.88.94 16 73 ms 74 ms 74 ms eth-ge0001-car1.orld-st.flhsi.com [208.90.222.250] 17 72 ms 72 ms 72 ms s06-sf0001-car1.xmas-tw.flhsi.com [208.90.222.193] 18 80 ms 74 ms 73 ms s06-sf0003-car1.coco-tw.flhsi.com [208.90.222.210] 19 72 ms 69 ms 72 ms s18-sf0001-car1.coco-vr.flhsi.com [208.90.221.201] 20 73 ms 72 ms 74 ms eth-ge0001-far1.coco-vr.flhsi.com [208.90.221.26] 21 74 ms 73 ms 76 ms mirror.flhsi.com [208.65.55.17] Trace complete. I can still download in under 60 seconds (more that 50Mbps). I had 17 retransmitted packets.

How fast was your download?

Looks like packet loss to me, but let's do a controlled test. Please perform the following steps: 1) Traceroute to mirror.anl.gov [146.137.96.7] which is the Argonne National Laboratory in Illinois, which should be a lot closer to you than me. Here's mine: Tracing route to mirror.anl.gov [146.137.96.7] over a maximum of 30 hops: 1 1 ms 1 ms <1 ms firewall.ibsutah.net [192.168.1.1] 2 13 ms 12 ms 9 ms 67.186.246.1 3 12 ms 13 ms 9 ms te-0-6-0-7-sur02.sandy.ut.utah.comcast.net [68.87.220.221] 4 10 ms 9 ms 12 ms te-0-7-0-0-sur01.sandy.ut.utah.comcast.net [69.139.247.17] 5 25 ms 17 ms 15 ms te-0-9-0-1-ar04.saltlakecity.ut.utah.comcast.net [68.87.170.5] 6 31 ms 28 ms 31 ms he-0-1-0-0-cr01.denver.co.ibone.comcast.net [68.86.90.225] 7 27 ms 30 ms 29 ms be-10717-cr02.denver.co.ibone.comcast.net [68.86.84.226] 8 44 ms 38 ms 47 ms be-11317-cr01.dallas.tx.ibone.comcast.net [68.86.84.229] 9 45 ms 45 ms 42 ms be-14-pe02.1950stemmons.tx.ibone.comcast.net [68.86.83.110] 10 38 ms 41 ms 44 ms xe-0-3-0.0.dlls0.tr-cps.internet2.edu [64.57.20.93] 11 53 ms 53 ms 54 ms xe-4-3-0.206.chic0.tr-cps.internet2.edu [64.57.20.207] 12 53 ms 56 ms 56 ms 64.57.20.1 13 60 ms 60 ms 71 ms 192.5.170.226 14 65 ms 62 ms 54 ms ciscore-v911-221c1hsrp.net.anl.gov [130.202.212.141] 15 56 ms 58 ms 55 ms mirror.anl.gov [146.137.96.7] Trace complete. 2) Launch Wireshark and enter a capture filter for host 146.137.96.7 on your Ethernet interface and start a capture. 3) Download http://mirror.anl.gov/pub/centos/7/isos/x86_64/CentOS-7.0-1406-x86_64-NetInstall.iso I can download this 362MB file in under 60 seconds at over 50Mbps. 4) Stop the capture, and then look at your expert infos. I had two retransmitted packets for the download.

https://testmy.net/ipb/topic/32071-upload-speed-issue-comcast/page-3?hl=%2Bpacket+%2Bcapture#entry345372

I think the key is convincing them to send out a tech who will do more than just do the Xfinity speed test like any monkey can. If they don't believe the TMN tests, fine - there are plenty of other ways to demonstrate download performance is poor. Give them a list of ten distinct download URLs to show that they are all slow...and I still think you should do a packet capture to look for packet loss, as I'm pretty sure you'll have it. You can also try quoting the classic line from the old Heaven Can Wait movie: The likelihood of one individual being right increases in direct proportion to the intensity with which others are trying to prove him wrong.

Which area of the country are you in, and are you still getting results from your first post - paying for 60/10, but only getting ~ 11 down most of the time? At my residence, I'm paying for 50/10 through Comcast, and consistently get it (my downloads are actually closer to 60Mbps most of the time), and TMN consistently verifies I'm getting what I'm paying for. It also verifies EBrown's Comcast 50/10, as well as a colleague of mine who lives about 30 miles North. If TMN is measuring less, I'd believe it, but I also believe you need to validate that with other real-world transfers to show the Comcast people they're FOS. At our office (which is about 7 miles from my house, in another suburb), we just got the Comcast Business 150/20 installed about two weeks ago. On that, the 20Mbit upload is consistent. Downloads, on the other hand, are more like 50Mbps. TMN verifies the "real world" results with other transfer tests, and jives with our NMS monitoring. The Xfinity speed test measures it at 107/20. When we first looked into Comcast Business several months ago, 100/20 was the fastest plan available, and it was only recently that 150/20 was available, although the sales guy said our building would need a new line drop to support it. That never happened, and I believe that to be the reason of the slower speeds. I haven't yet tested from their modem (bypassing our equipment), but will likely take it up with them in the Sping, when weather would allow a new line drop. Even the 50Mbps for us is sooo much faster than what we had before, so we're happy for now, but still not getting what we should. Last but not least, have you performed a packet capture during a transfer test, to see if there is packet loss happening?

Nice. I tried the BBB approach with our ISP and it got us nowhere.

Nope. But I'm also a transplant; moved to the area from Colorado in '97, which I consider my "real" home

Do you know how far it is from the line tap on your house to the Comcast box on the street? We're fortunate in that their box is right in front of our house (making my wife's flower arrangements less pretty), and they ran a new cable from that to our house many years ago, I guess because the existing one wasn't "up to spec," which they discovered when we used to have cable TV + phone rather than just Internet.

I would totally leverage that...you could take your laptop over to his house and wire in, run a selection of upload tests with captures to different endpoints, and compare those with the results at your place using the same laptop. If the results are dramatically different, I don't see how the Comcast techs could deny there's something up with your last mile. I get that ICMP traffic isn't going to be prioritized, but that prioritization only comes into play when there is congestion, and I wouldn't think there would be congestion for services internal to their network. As we've seen from our office experience, packet loss issues are much more apparent for transfers with endpoints far away.

Ha! We're in Sandy; my wife's parents live in Murray. My oldest son graduated from Bountiful High...still working on getting the other two graduated . Oddly enough, none of them seem to want to be a computer nerd like me.

Glad you got it sorted; my suggestion was going to be EasyBCD.