web statisticsweb stats Business Phone Systems Tech Talk Forum - VOIP & Cloud Phone Help

Business Phone Systems

Previous Thread
Next Thread
Print Thread
Rate Thread
#492570 07/11/08 04:08 AM
Joined: Jan 2005
Posts: 15,378
Likes: 13
Moderator-Vertical, Vodavi, 1A2, Outside Wire
*****
OP Offline
Moderator-Vertical, Vodavi, 1A2, Outside Wire
*****
Joined: Jan 2005
Posts: 15,378
Likes: 13
Story HERE


Ed Vaughn, MBSWWYPBX
Atcom VoIP Phones
VoIP Demo

Best VoIP Phones Canada


Visit Atcom to get started with your new business VoIP phone system ASAP
Turn up is quick, painless, and can often be done same day.
Let us show you how to do VoIP right, resulting in crystal clear call quality and easy-to-use features that make everyone happy!
Proudly serving Canada from coast to coast.

Joined: Mar 2008
Posts: 457
Member
Offline
Member
Joined: Mar 2008
Posts: 457
pretty interesting... i've wondered about their methods and, knowing how some folks abuse P2P services, somewhat understand why they did what they did.. but this seems like a good response.


"There is one thing and only one thing in which it is granted to you to be free in life, all else being beyond your power: that is to recognize and profess the truth." - Leo Tolstoy
Joined: Jan 2007
Posts: 1,951
Likes: 2
Member
*****
Offline
Member
*****
Joined: Jan 2007
Posts: 1,951
Likes: 2
You can manage network bandwidth without controlling the content.

Apparently, Comcast doesn't believe this is true. Either that or they are simply taking the easy way out by blocking well-known ports of file sharing programs.

The latter tactic is sophomoric.


"Press play and record at the same time" -- Tim Alberstein
Joined: Aug 2005
Posts: 6,692
Member
Offline
Member
Joined: Aug 2005
Posts: 6,692
We have had some problems in the past at WiFi locations served by Comcast when we tried to initiate a VPN tunnel back to a client site. Perhaps they were trying to block P2P on a more advanced level as well.

Joined: Jul 2008
Posts: 8
Member
Offline
Member
Joined: Jul 2008
Posts: 8
I worked for several years for a cable company, I am confident that many cable companys will begin or are doing the same now.

The internet was not designed to handle the traffic it is hammerd with today. More true many cable companies have way too many actives on a node, P2P traffic causes serious latency issues on those nodes, which can and will effect all services, VoIP, Video, and Data.

I have noticed my connection gets throttled when I use NetFlix. Watching the throughput on my line with OpenXtra it seems obvious that after a few minutes the bandwidth is throttled from 10mbps to under 200kbps. Watching the trace shows no signs of a bottleneck.

I do know that NetFlix uses high ports and low ports and could easily be viewed as warez bandwidth. The point of the story? I dont have one, as I am really inclined to support traffic shaping, why allow a few users to absorb all the bandwidth?

Joined: Mar 2008
Posts: 457
Member
Offline
Member
Joined: Mar 2008
Posts: 457
How do you know you're getting throttled when you use Netflix? Or for that matter, know who is doing the throttling? Maybe you're just seeing the effect of a bursting service such as Comcast's Powerboost... or maybe after a few minutes your buffer is full and it slows down the stream to the speed you're watching it. Netflix, unlike YouTube, doesn't buffer the whole clip - just the bit ahead of what you're watching right now.

I'm not sure I understand why you think using "high ports and low ports" could "easily be viewed as warez bandwidth." Besides, doesn't Netflix's software use random port numbers?

Quote
Originally posted by dagwoodsystems:
Apparently, Comcast doesn't believe this is true. Either that or they are simply taking the easy way out by blocking well-known ports of file sharing programs.
No, they were using Sandvine to monitor and disrupt P2P activity specifically by forging TCP packets with the RST flag set on outbound traffic, causing the connections to be dropped. Thus, Comcast P2P users got great download speeds while uploads would slow to a crawl. Clever, but not cool according to the FCC.


"There is one thing and only one thing in which it is granted to you to be free in life, all else being beyond your power: that is to recognize and profess the truth." - Leo Tolstoy
Joined: Jan 2007
Posts: 1,951
Likes: 2
Member
*****
Offline
Member
*****
Joined: Jan 2007
Posts: 1,951
Likes: 2
I've done a little reading about Sandvine, and they sound like an interesting company. They have certainly had a wild ride from private to publically-traded.

Sandvine boasts the ability to allow video conferencing, VoIP and gaming traffic through, while quenching or controlling P2P traffic. Seeing that I can strap BitTorrent to use the well-known ports that common networked games use, how is one to distinguish one from the other? Like P2P software, these games also send and receive a pretty solid stream of traffic.

From my reading, it appears that Sandvine does so by employing heavy SPI (apparently to the point where they can recognize the specific details of a P2P session). That's pretty clever, but this is a cat and mouse game. The service provider is ahead at the moment, but I suspect some smart guy will develop a new sharing algorithm that, for example, mimics popular game traffic, such as that of "Call of Duty 4".

Still, that's very interesting. I appreciate your inside knowledge of Comcast's network management. Thanks.


"Press play and record at the same time" -- Tim Alberstein
Joined: Jul 2008
Posts: 8
Member
Offline
Member
Joined: Jul 2008
Posts: 8
I gave you the tools I used, I told you when and how, I accomadated the "random port". The only thing I left out was the lag seen on the first three hops. I used common traffic analyzers, I also stated that it is possible its simply load on the node.

I did not say that I knew for sure, but I suspect something when a 10Meg service is loading a buffer with a 35 minute wait.

Joined: Mar 2008
Posts: 457
Member
Offline
Member
Joined: Mar 2008
Posts: 457
Quote
Originally posted by Jeremy Wood:
I did not say that I knew for sure, but I suspect something when a 10Meg service is loading a buffer with a 35 minute wait.
Calm down there young'n, I'm not here to spar with ya. I'm just saying there's "more true many" ways to understand what you're seeing. Or maybe I have trouble understanding your writing.

Quote
Originally posted by dagwoodsystems:
From my reading, it appears that Sandvine does so by employing heavy SPI (apparently to the point where they can recognize the specific details of a P2P session). That's pretty clever, but this is a cat and mouse game. The service provider is ahead at the moment, but I suspect some smart guy will develop a new sharing algorithm that, for example, mimics popular game traffic, such as that of "Call of Duty 4".
I don't know if it's SPI per se, but they've definitely got the technology to do deep enough analysis to sort traffic by application and do it fast enough to handle being in the same rack as the BGP gear in a very large server room. I've heard a few good ideas for working around it but you're absolutely right: it's a cat & mouse game.

I'm curious to see if they keep going after the pirates or if their attention shifts when other activities take over the title of bandwidth hog.


"There is one thing and only one thing in which it is granted to you to be free in life, all else being beyond your power: that is to recognize and profess the truth." - Leo Tolstoy
Joined: Jul 2008
Posts: 8
Member
Offline
Member
Joined: Jul 2008
Posts: 8
Quote
Originally posted by 93mdk93:
Other activities take over the title of bandwidth hog.
Great point.
I did not try to sound rude, just came out that way. In the latter part of my initial post I actually said that I agree with some packet shaping, I also indicated that system operators are also to blame for latency issues.

Comcast from first hand experience overloads nodes, does not do enough sweeps, and for the most part can’t staff enough to maintain the system and its actives.

Again no disrespect, thanks for the discussion.


Link Copied to Clipboard
Forum Statistics
Forums84
Topics94,262
Posts638,693
Members49,757
Most Online5,661
May 23rd, 2018
Popular Topics(Views)
211,098 Shoretel
187,703 CTX100 install
186,792 1a2 system
Newest Members
BPopilek, Rich F, LewisR, TDKs79, Buttinset
49,757 Registered Users
Top Posters(30 Days)
dexman 18
Toner 14
TDKs79 8
Who's Online Now
1 members (Curlycord), 77 guests, and 246 robots.
Key: Admin, Global Mod, Mod
Contact Us | Sponsored by Atcom: One of the best VoIP Phone Canada Suppliers for your business telephone system!| Terms of Service

Sundance Communications is not affiliated with any of the above manufacturers. Sundance Phone System Forums - VOIP & Cloud Phone Help
©Copyright Sundance Communications 1998-2024
Powered by UBB.threads™ PHP Forum Software 7.7.5