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: CAnet-3-NEWS@canarie.ca 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.
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: CAnet-3-NEWS@canarie.ca 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]
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: houle@acns.fsu.edu. Academic Computing & Network Services Voice: 850-644-2591 Florida State University FAX: 850-644-8722
On Wed, 24 Apr 2002, Art Houle wrote:
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.
-always close out tickets 60 seconds before they are scheduled to be escalated, even if the problem is still open. -Dan -- [-] Omae no subete no kichi wa ore no mono da. [-]
Art Houle wrote:
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.
You forgot my favorite : Every trouble report from a customer must include at least 2 hours on hold before a ticket is opened. Regards Marshall Eubanks
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: CAnet-3-NEWS@canarie.ca 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]
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: houle@acns.fsu.edu. Academic Computing & Network Services Voice: 850-644-2591 Florida State University FAX: 850-644-8722
-- Regards Marshall Eubanks This e-mail may contain confidential and proprietary information of Multicast Technologies, Inc, subject to Non-Disclosure Agreements T.M. Eubanks Multicast Technologies, Inc 10301 Democracy Lane, Suite 410 Fairfax, Virginia 22030 Phone : 703-293-9624 Fax : 703-293-9609 e-mail : tme@multicasttech.com http://www.multicasttech.com Test your network for multicast : http://www.multicasttech.com/mt/ Status of Multicast on the Web : http://www.multicasttech.com/status/index.html
On Wed, 24 Apr 2002, Art Houle wrote:
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.
Don't forget to schedule maintenance as often as possible. After all, if a customer doesn't get any service because there is a maintenance they don't mind, but if the same service disruption is because of an outage they get upset.
Even disregarding the issue of whether 99.999% network reliability is possible, people have made it abundantly clear that they don't want it. In this case I define "to want" as "to be willing to pay even a little bit extra for". This is even the case in POTS telephony. I know lots of people who are happy to use 2 cpm long distance from Priceline et al, even though half the time the call doesn't go through. -- John R. Levine, IECC, POB 727, Trumansburg NY 14886 +1 607 387 6869 johnl@iecc.com, Village Trustee and Sewer Commissioner, http://iecc.com/johnl, Member, Provisional board, Coalition Against Unsolicited Commercial E-mail
This is the sort of thing that can be discussed forever, but here's an anecdote anyway: At my previous employer, we hired a lot of people who had spent their entire careers either running or developing equipment for TDM voice networks. Their view of five nines for voice was that the network was "up" if the voice signaling infrastructure worked as designed -- not that you could actually get calls through the network. So, for example, if your long distance call could not be completed because bearer trunks were down, there wasn't enough capacity etc. etc. then the voice network was still "up" for five 9s calculation purposes even though you couldn't use it for its intended purpose. How many times have you received the "All circuits are busy" message? Some would say that was the voice network failing to function -- the Bell-shaped heads said it was working as designed. They were clear that what mattered was the signaling integrity of the network, not the application of voice connectivity itself. So, if you can get dial tone but not place a call, that's five 9s reliability at work. When applied randomly to the Internet, I suppose that means if you can dial into a RAS and establish a PPP/IPCP session, but the RAS' connection to the Internet is down, then the service is up :-) Cheers, Mathew At 04:51 PM 4/24/2002 -0400, Art Houle wrote:
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: CAnet-3-NEWS@canarie.ca 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]
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: houle@acns.fsu.edu. Academic Computing & Network Services Voice: 850-644-2591 Florida State University FAX: 850-644-8722
| Mathew Lodge | mathew@cplane.com | | Director, Product Management | Ph: +1 408 789 4068 | | CPLANE, Inc. | http://www.cplane.com |
[stuff missing] When applied randomly to the Internet, I suppose that means if you can dial into a RAS and establish a PPP/IPCP session, but the RAS' connection to the Internet is down, then the service is up :-) [stuff missing] I seem to remember a large internet provider's service contract reading something to the effect of. "Your server is considered down if customer router cannot pass packets [or ping] with service provider's immediate upstream router." This is a functional description of the above for dedicated lines as customer aggregation routers never talked to the internet, so if there was a problem at a transit router you weren't getting anywhere. A modern contract I saw recently defined "up" for colocation purposes as "the customer's assigned gigabit port is available." Though available was not a defined term, one could not easily apply that to a ports' willingness to pass packets. One could say a congested port was not available though I guess. Deepak Jain AiNET
Doh. This should have read "Your service" not "Your server". -----Original Message----- From: owner-nanog@merit.edu [mailto:owner-nanog@merit.edu]On Behalf Of Deepak Jain Sent: Thursday, April 25, 2002 4:26 PM To: Mathew Lodge; Art Houle; Pete Kruckenberg Cc: nanog@merit.edu Subject: RE: The Myth of Five 9's Reliability (fwd) [stuff missing] When applied randomly to the Internet, I suppose that means if you can dial into a RAS and establish a PPP/IPCP session, but the RAS' connection to the Internet is down, then the service is up :-) [stuff missing] I seem to remember a large internet provider's service contract reading something to the effect of. "Your server is considered down if customer router cannot pass packets [or ping] with service provider's immediate upstream router." This is a functional description of the above for dedicated lines, as customer aggregation routers never talked to the internet, so if there was a problem at a transit router you weren't getting anywhere. A modern contract I saw recently defined "up" for colocation purposes as "the customer's assigned gigabit port is available." Though available was not a defined term, one could not easily apply that to a ports' willingness to pass packets. One could say a congested port was not available though, I guess. Deepak Jain AiNET
On Wed, 24 Apr 2002, Art Houle wrote:
Date: Wed, 24 Apr 2002 16:51:53 -0400 (EDT) From: Art Houle <houle@zeppo.acns.fsu.edu> To: Pete Kruckenberg <pete@kruckenberg.com> Cc: nanog@merit.edu Subject: 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.
- Every ticket goes to "Open-Fixed" before hanging up... -- Yours, J.A. Terranson sysadmin@mfn.org If Governments really want us to behave like civilized human beings, they should give serious consideration towards setting a better example: Ruling by force, rather than consensus; the unrestrained application of unjust laws (which the victim-populations were never allowed input on in the first place); the State policy of justice only for the rich and elected; the intentional abuse and occassionally destruction of entire populations merely to distract an already apathetic and numb electorate... This type of demogoguery must surely wipe out the fascist United States as surely as it wiped out the fascist Union of Soviet Socialist Republics. The views expressed here are mine, and NOT those of my employers, associates, or others. Besides, if it *were* the opinion of all of those people, I doubt there would be a problem to bitch about in the first place... --------------------------------------------------------------------
-----Original Message----- From: owner-nanog@merit.edu [mailto:owner-nanog@merit.edu]On Behalf Of Art Houle Sent: Wednesday, April 24, 2002 1:52 PM To: Pete Kruckenberg Cc: nanog@merit.edu Subject: 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'.
These can all accomplished with one simple and elegant system policy rule. It also has the advantage of "tuneability". If you hold off determining if there is an interruption of service for X minutes, then NO interruptions of service shorter than X minutes exist, since the service is functional when tested. Also, a call center that first "routes" tickets to the "appropriate area" can deliver 99.99 with little effort. ( in fact, the LESS effort/clue, the BETTER the rating ! ) BTW - One of my best friends growing up ( and we took EE together ) grandfather was the V.P. in charge of AT&T's LongLines division while a lot of the "wire was pulled". From what he said of his grandfather's remarks, they didn't think about five 9's. The question was how much spare/redundant capacity did you have, both for dependability and to support the countries growth. Not exactly "this quarter's profit" thinking -sigh-. Bruce Williams "Two is not equal to three, even for large values of two"
But THAT was when phones had cranks on the side. ;) 5 nines is a myth, conjured up by sales cretins to have something to sell...If I remember, 5 nines translates to 6 minutes outage a YEAR..? (Correct me if I'm wrong here) It's a marketing ploy for liar sales people and CEO's, it has absolutely NOTHING to do with real-world conditions.
BTW - One of my best friends growing up ( and we took EE together ) grandfather was the V.P. in charge of AT&T's LongLines division while a lot of the "wire was pulled". From what he said of his grandfather's remarks, they didn't think about five 9's. The question was how much spare/redundant capacity did you have, both for dependability and to support the countries growth. Not exactly "this quarter's profit" thinking -sigh-.
participants (11)
-
Art Houle -
blitz -
Bruce Williams -
Dan Hollis -
Deepak Jain -
Iljitsch van Beijnum -
johnl＠iecc.com -
Marshall Eubanks -
Mathew Lodge -
measl＠mfn.org -
Pete Kruckenberg