Re: QoS/CoS in the real world?
We are using QOS to preferentially drop packets that represent file-sharing (kazaa, gnutella, etc). This saves us 40Mbps of traffic across our multiple congested WAN links. The trick is to mark packets meaningfully. Also, the WFQ introduces some additional latency at our edge. On Sun, 14 Jul 2002, Stephen J. Wilcox wrote: Well, end of the week and the responses dried up pretty quickly, I think thats a response in itself to my question! Okay, heres a summary which was requested by a few people: Other people too are interested in my questions, they dont implement QoS in any saleable manner and wonder how it can be done and whats actually required. A number of people think QoS was interesting for a while but that its never either found its true use or is dead. There are unresolved questions from a customer point of view as to what they are actually going to get, what difference it will make and how they can measure their performance and the improvements from QoS. There is a real demand for guaranteed bandwidth, however this tends to be in the form of absolute guarantees rather than improvements above normal hence ATM remaining a popular solution. There is a requirement to differentiate voice traffic, however this is necessarily done by the network anyway in order to offer the service, this being the case the customer doesnt pay extra or gets to know much about how all the fancy bits are done. On the face of it this is all negative. Nobody has responded saying there are genuine requirements for services to be offered to customers. Nor has anybody responded with any descriptions of implementations. I conclude either the people doing this are successful and keep their secret safe or the world is yet to sell largescale QoS across IP. Steve On Mon, 8 Jul 2002, Stephen J. Wilcox wrote: Hi all, I've been looking through the various qos/cos options available, my particular area was in how IP (MPLS perhaps) compares and can be a substitute for ATM. Well, theres lots of talk and hype out there, from simple IP queuing eg cisco priority queuing, rsvp, diffserv, mpls traffic engineering etc But two things are bugging me.. 1. To what extent have providers implemented QoS for their customers 2. Hype aside, to what extent do customers actually want this (and by this I dont just mean that they want the latest QoS because its the 'latest thing', there has to be a genuine reason for them to want it). And this takes me back to my ATM reference where there is a clear major market still out there of ATM users and what would it take to migrate them to an IP solution? Also, how are people implementing bandwidth on demand (dynamic allocation controlled by the customer) solutions to customers Cheers Steve Art Houle e-mail: [EMAIL PROTECTED] Academic Computing Network ServicesVoice: 850-644-2591 Florida State University FAX: 850-644-8722
Re: QoS/CoS in the real world?
On Sun, 14 Jul 2002, Marshall Eubanks wrote: On Sun, 14 Jul 2002 21:13:13 -0400 (EDT) Art Houle [EMAIL PROTECTED] wrote: We are using QOS to preferentially drop packets that represent file-sharing (kazaa, gnutella, etc). This saves us 40Mbps of traffic across our multiple congested WAN links. The trick is to mark packets meaningfully. Also, the WFQ introduces some additional latency at our edge. Is this different from port filtering as is commonly done with, e.g., gnutella ? Or, to put it another way, how are the packets marked ? And why not just drop them then and there, instead of later ? If we are not using our WAN connections to capacity, then p2p traffic can expand and fill the pipe, but if business packets are filling the pipes, then the p2p stuff is throttled back. This makes 100% use of an expensive resource. Regards Marshall Eubanks On Sun, 14 Jul 2002, Stephen J. Wilcox wrote: Well, end of the week and the responses dried up pretty quickly, I think thats a response in itself to my question! Okay, heres a summary which was requested by a few people: Other people too are interested in my questions, they dont implement QoS in any saleable manner and wonder how it can be done and whats actually required. A number of people think QoS was interesting for a while but that its never either found its true use or is dead. There are unresolved questions from a customer point of view as to what they are actually going to get, what difference it will make and how they can measure their performance and the improvements from QoS. There is a real demand for guaranteed bandwidth, however this tends to be in the form of absolute guarantees rather than improvements above normal hence ATM remaining a popular solution. There is a requirement to differentiate voice traffic, however this is necessarily done by the network anyway in order to offer the service, this being the case the customer doesnt pay extra or gets to know much about how all the fancy bits are done. On the face of it this is all negative. Nobody has responded saying there are genuine requirements for services to be offered to customers. Nor has anybody responded with any descriptions of implementations. I conclude either the people doing this are successful and keep their secret safe or the world is yet to sell largescale QoS across IP. Steve On Mon, 8 Jul 2002, Stephen J. Wilcox wrote: Hi all, I've been looking through the various qos/cos options available, my particular area was in how IP (MPLS perhaps) compares and can be a substitute for ATM. Well, theres lots of talk and hype out there, from simple IP queuing eg cisco priority queuing, rsvp, diffserv, mpls traffic engineering etc But two things are bugging me.. 1. To what extent have providers implemented QoS for their customers 2. Hype aside, to what extent do customers actually want this (and by this I dont just mean that they want the latest QoS because its the 'latest thing', there has to be a genuine reason for them to want it). And this takes me back to my ATM reference where there is a clear major market still out there of ATM users and what would it take to migrate them to an IP solution? Also, how are people implementing bandwidth on demand (dynamic allocation controlled by the customer) solutions to customers Cheers Steve Art Houle e-mail: [EMAIL PROTECTED] Academic Computing Network ServicesVoice: 850-644-2591 Florida State University FAX: 850-644-8722 Art Houle e-mail: [EMAIL PROTECTED] Academic Computing Network ServicesVoice: 850-644-2591 Florida State University FAX: 850-644-8722
Re: The Myth of Five 9's Reliability (fwd)
How to calculate uptime and get 5 9s -do not include any outage less than 20 minutes. -only include down lines that are actually reported by customers. -when possible fix the line and report 'no trouble found'. -remember that your company is penalized by the FCC for bad ratings, so don't report any problems that you do not have to. On Wed, 24 Apr 2002, Pete Kruckenberg wrote: From the Canarie news mailing list. I don't think I've ever experienced five 9's on any telco service, I have always assumed I must be the one customer experiencing down-time, and the aggregate was somehow five 9's. How is network reliability calculated to end up with five 9's? Pete. -- Forwarded message -- Date: Wed, 24 Apr 2002 10:08:18 -0400 (EDT) From: [EMAIL PROTECTED] Subject: [news] The Myth of Five 9's Reliability For more information on this item please visit the CANARIE CA*net 3 Optical Internet program web site at http://www.canet3.net/news/news.html --- [A good article on the truth about five 9's reliability. Some excerpts - BSA] http://www.bcr.com/forum Deep Six Five-Nines? For much of the 20th century, the U.S. enjoyed the best network money could buy; hands-down, it was the most modern, most ubiquitous and most reliable in the world. And one term--five-nines--came to symbolize the network's robustness, its high availability, its virtual indestructibility. When the goal of five-nines was set, the network was planned, designed and operated by a monopoly, which was guaranteed a return on whatever it invested. It was in the monopoly's interest to make the network as platinum-plated as possible. One of the key points is that five-nines has long been somewhat overrated. Five-nines is NOT an inherent capability of circuit-switched, TDM networks. It's a manmade concept, derived from a mathematical equation, which includes some things and leaves out others. It's critical to remember that when you run the performance numbers on ALL the items in a network--those that are included in the five-nines equation and those that aren't--you're probably going to wind up with a number less than 99.999 percent. A well-run network actually delivers something around 99.45 percent. The gap between the rhetoric of five-nines and actual network performance leads to the conclusion that five-nines may not be a realistic or even necessary goal. Art Houle e-mail: [EMAIL PROTECTED] Academic Computing Network ServicesVoice: 850-644-2591 Florida State University FAX: 850-644-8722
