Bell Labs' Discovery May Lead to Efficient Networks
FYI: Bell Labs recently conducted an analysis of the nature of Internet traffic. Some pretty interesting findings. http://Networking.ittoolbox.com/browse.asp?c=NetworkingNews&r=/news/dispnews .asp?i=44100 Through the use of sophisticated new software programs that analyzed and simulated data traffic in "unprecedented detail," Bell Labs researchers found that the "burstiness" seen in traffic at the edges of the Internet disappears at the core. The discovery that traffic on heavily loaded, high-capacity network links is unexpectedly regular may point the way to more efficient system and network designs with better performance at lower cost, Bell Labs said.
There had been reports of this discover about four years ago -- as I recall, Tony Li reported hearing from customers that traffic levels at the core were remarkably stable. I had some talks with various of the self-similarity experts at the time and they said this was perfectly plausible -- the law of large numbers eventually says this must happen, the self-similarly results simply implied that the amount of traffic required to reach stability was *much* larger than required if traffic was Poisson. At the core, we've apparently reached that point. My recollection of the discussions is that there's a lot of interesting work to be done on the structure of those stable flows (what's going on within the aggregate) as well as working out where the traffic gets small enough to become self-similar. But these discussions were a few years ago and my memory may be faulty. Craig In message <0C875DC28791D21192CD00104B95BFE70146DD09@BGSLC02>, Irwin Lazar writ es:
FYI: Bell Labs recently conducted an analysis of the nature of Internet traffic. Some pretty interesting findings.
http://Networking.ittoolbox.com/browse.asp?c=NetworkingNews&r=/news/dispnews .asp?i=44100
Through the use of sophisticated new software programs that analyzed and simulated data traffic in "unprecedented detail," Bell Labs researchers found that the "burstiness" seen in traffic at the edges of the Internet disappears at the core. The discovery that traffic on heavily loaded, high-capacity network links is unexpectedly regular may point the way to more efficient system and network designs with better performance at lower cost, Bell Labs said.
On Thu, 7 Jun 2001, Craig Partridge wrote:
I had some talks with various of the self-similarity experts at the time and they said this was perfectly plausible -- the law of large numbers eventually says this must happen, the self-similarly results simply implied that the amount of traffic required to reach stability was *much* larger than required if traffic was Poisson. At the core, we've apparently reached that point.
I attended a seminar where self-similarty people from Ericsson were talking (At IETF INET2001). They had not tested the theory with thousands of TCP connections on high capacity links, but one thing that caught my eye was that for self similarity to occur, congestion need to exist (according to them). Well, if you have congestion in your core, you're doing something wrong. Fix it, and the problem goes away (at least in the core). Same thing with end-to-end QoS that some people were talking about there (for some reason, they all seemed to originate from the telephony world, god knows why *smirk*), you only need QoS in the core if you have congestion, and then you're only throwing manhours at the problem instead of buying hardware and more capacity. I'd go for overprovisioning every day of the week. -- Mikael Abrahamsson email: swmike@swm.pp.se
In message <Pine.LNX.4.33.0106071834370.853-100000@uplift.swm.pp.se>, Mikael Ab rahamsson writes:
I attended a seminar where self-similarty people from Ericsson were talking (At IETF INET2001). They had not tested the theory with thousands of TCP connections on high capacity links, but one thing that caught my eye was that for self similarity to occur, congestion need to exist (according to them).
I'd have to see the Ericsson work. And I'm not an expert in self-similarity though I try to keep up with the papers. That said, the work I've seen to date on self-similarity has nothing to do with congestion. It often does have to do with traffic interacting with other traffic. But the queues don't have to be full, or even near full, for interactions to occur. Craig
FYI: Bell Labs recently conducted an analysis of the nature of Internet traffic. Some pretty interesting findings.
http://Networking.ittoolbox.com/browse.asp?c=NetworkingNews&r=/new s/dispnews .asp?i=44100
This is nothing too new. We have seen for quite some time that the greater the aggregate the less bursty it is. Usage of T3 and above links seem to pretty stable. It seems that aggregation of a certain number of bursty flows produces a predictable traffic pattern. ...djr...
[ On Thursday, June 7, 2001 at 09:26:02 (-0600), Irwin Lazar wrote: ]
Subject: Bell Labs' Discovery May Lead to Efficient Networks
Through the use of sophisticated new software programs that analyzed and simulated data traffic in "unprecedented detail," Bell Labs researchers found that the "burstiness" seen in traffic at the edges of the Internet disappears at the core. The discovery that traffic on heavily loaded, high-capacity network links is unexpectedly regular may point the way to more efficient system and network designs with better performance at lower cost, Bell Labs said.
Anyone with a dozen busy dial-up ports could have told them that.... -- Greg A. Woods +1 416 218-0098 VE3TCP <gwoods@acm.org> <woods@robohack.ca> Planix, Inc. <woods@planix.com>; Secrets of the Weird <woods@weird.com>
hmm, unprecedented that.. who'd have thought it huh? ground breaking stuff jeezus glad they invested the time and energy On Thu, 7 Jun 2001, Irwin Lazar wrote:
FYI: Bell Labs recently conducted an analysis of the nature of Internet traffic. Some pretty interesting findings.
http://Networking.ittoolbox.com/browse.asp?c=NetworkingNews&r=/news/dispnews .asp?i=44100
Through the use of sophisticated new software programs that analyzed and simulated data traffic in "unprecedented detail," Bell Labs researchers found that the "burstiness" seen in traffic at the edges of the Internet disappears at the core. The discovery that traffic on heavily loaded, high-capacity network links is unexpectedly regular may point the way to more efficient system and network designs with better performance at lower cost, Bell Labs said.
-- Stephen J. Wilcox IP Services Manager, Opal Telecom http://www.opaltelecom.co.uk/ Tel: 0161 222 2000 Fax: 0161 222 2008
participants (6)
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Craig Partridge -
Deron J. Ringen -
Irwin Lazar -
Mikael Abrahamsson -
Stephen J. Wilcox -
woods＠weird.com