aCp
asked on
Network optimization, reliability, etc.
Hi. First of all I must say that this question is VERY general, and therefore not closely related to computers. I have a work to do on network analysis, and by that I mean trying to arrange a network having some conditions imposed by a third-party, for instance lowest cost, or most reliable, or even most efficient (fastest, etc.).
Now I know pratically nothing on networks, and want to find scientific articles so as to gather the most of info I can.
I started a search with search engines but unfortunately this isn't the best way, MANY results not being helpful. I must say that I am somehow lost and can't find anything to start from.
So what I am looking for is some links that will help me for my research, on network analysis and mostly on network optimization.
Thanks in advance experts!
aCp
Now I know pratically nothing on networks, and want to find scientific articles so as to gather the most of info I can.
I started a search with search engines but unfortunately this isn't the best way, MANY results not being helpful. I must say that I am somehow lost and can't find anything to start from.
So what I am looking for is some links that will help me for my research, on network analysis and mostly on network optimization.
Thanks in advance experts!
aCp
ASKER
Here is for example a site that appeared quite usefull but clearly not enough:
http://ubmail.ubalt.edu/~harsham/opre640A/partIII.htm
http://ubmail.ubalt.edu/~harsham/opre640A/partIII.htm
Hate to say it, but you may want to get a consultant in on this project. There's a lot of little things to consider that, if overlooked, could eliminate your cost estimate.
For example, I had a client that decided he knew more about setting up the network than I did. I installed the equipment he purchased, configured it the way he told me to, and then billed him again to come in and fix the slow, choppy network. The bill for fixing it was almost triple the install bill.
Just to state the obvious, most reliable and fastest should not be in the same sentance as lowest cost.
For example, I had a client that decided he knew more about setting up the network than I did. I installed the equipment he purchased, configured it the way he told me to, and then billed him again to come in and fix the slow, choppy network. The bill for fixing it was almost triple the install bill.
Just to state the obvious, most reliable and fastest should not be in the same sentance as lowest cost.
aCp;
I think deltree was being kind to say that you might want to get a consultant. I think it is a very low probability that you can educate yourself to the point of being able to make accurate and educated decisions about network reliability, efficiency, etc. based on looking at some web pages. Most of "us" have spent years working with networks - designing, installing, troubleshooting . . .
Good luck.
Steve
I think deltree was being kind to say that you might want to get a consultant. I think it is a very low probability that you can educate yourself to the point of being able to make accurate and educated decisions about network reliability, efficiency, etc. based on looking at some web pages. Most of "us" have spent years working with networks - designing, installing, troubleshooting . . .
Good luck.
Steve
If this is a student project, then I would go to the MS and Cisco sites and look up tuning and optimizing networks.
Other than that, it is probabl best to buy a good book on the subject and start reading.
Amazon is a good place to start.
I hope this helps !
Other than that, it is probabl best to buy a good book on the subject and start reading.
Amazon is a good place to start.
I hope this helps !
ASKER
Ok, first of all thanks to u Experts for ur comments, but I realize from ur answers that I didn't manage to explain correctly my problem. Actually I am a student in France and want to find how a network can be optimized, or analysed, using mathematical tools such as matrices (I have one article which looks a networks reliability using matrices). Now I don't want to learn the most I can on networks, I only want to make a research and then present the information I found to my class.
So what I'm looking is for example a scientific article taking a problem (finding the shortest path between 2 nodes), analysing it and solving it using mathematics.
I hope then having gathered some examples being able to make a little resume of them, and to present this to others.
I hope I was now more precise...
Thanks again :)
aCp
So what I'm looking is for example a scientific article taking a problem (finding the shortest path between 2 nodes), analysing it and solving it using mathematics.
I hope then having gathered some examples being able to make a little resume of them, and to present this to others.
I hope I was now more precise...
Thanks again :)
aCp
ASKER
SysExpert I took - I must admit - a rather quick look at Cisco's and MS site but found only information on now their applications could be used on improving a network.
Isn't there a more general approach on networks, using maths and not computers, or maybe a presentation of the algorithms used in their apps, so as to make a network optimization ?
Thanks in advance
aCp
Isn't there a more general approach on networks, using maths and not computers, or maybe a presentation of the algorithms used in their apps, so as to make a network optimization ?
Thanks in advance
aCp
If you are interested in statistical probability as it relates to network traffic you should look at some of the IEEE sites . . . or search on Ehrlang or stochastic modeling.
Good luck.
Steve
Good luck.
Steve
ASKER
Well the article I mentionned above that worked on the reliability of a network had much on probability and this is one of the reasons why I decided to turn and give more attention on optimization, probability not being appreciated unfortunately by the teachers... :)
But, the reason I post a comment now is that I didn't understand the references SteveJ gave me :
IEEE, now I'm not sure but is it a way of connecting computers (like Firewire)? And Ehrlang, stochastic modeling ?
Sorry my knowledge is pretty restricted and I didn't understand exactly, could you help a little bit more please SteveJ ?
Thanks a lot!
But, the reason I post a comment now is that I didn't understand the references SteveJ gave me :
IEEE, now I'm not sure but is it a way of connecting computers (like Firewire)? And Ehrlang, stochastic modeling ?
Sorry my knowledge is pretty restricted and I didn't understand exactly, could you help a little bit more please SteveJ ?
Thanks a lot!
ASKER
Ok, I went to www.ideee.org and faced the same problems, can't find a document matching my demands. I must be doing something wrong too, it can't be. I'm trying to find my way through their navigation bar and if I don't get to an end I use their search engine, still, nothing seems to be close to what I'm looking for.
Should I look at a specific part of their site, and I mean for MS, Cisco, and IEEE ? Is their some kind of part dedicated to students looking for info on technologies, here more precisely networks ?
aCp
Should I look at a specific part of their site, and I mean for MS, Cisco, and IEEE ? Is their some kind of part dedicated to students looking for info on technologies, here more precisely networks ?
aCp
ASKER
and it was www.ieee.org :)
I was suggesting that site because it MAY have the source documents that reference algorithms used in ethernet (for example) communications such as IEEE 802 committe specifications.
Regarding Erlang:
An Erlang is a unit of telecommunications traffic measurement. Strictly speaking, an Erlang represents the continuous use of one voice path. In practice, it is used to describe the total traffic volume of one hour.
For example, if a group of user made 30 calls in one hour, and each call had an average call duration of 5 minutes, then the number of Erlangs this represents is worked out as follows:
Minutes of traffic in the hour = number of calls x duration
Minutes of traffic in the hour = 30 x 5
Minutes of traffic in the hour = 150
Hours of traffic in the hour = 150 / 60
Hours of traffic in the hour = 2.5
Traffic figure = 2.5 Erlangs
Erlang traffic measurements are made in order to help telecommunications network designers understand traffic patterns within their voice networks. This is essential if they are to successfully design their network topology and establish the necessary trunk group sizes.
Erlang traffic measurements or estimates can be used to work out how many lines are required between a telephone system and a central office (PSTN exchange lines), or between multiple network locations.
Erlang traffic models
Several traffic models exist which share their name with the Erlang unit of traffic. They are formulae which can be used to estimate the number of lines required in a network, or to a central office (PSTN exchange lines). A formula also exists to model queuing situations, and lends itself well to estimating the agent staffing requirements of call centers.
The main Erlang traffic model are listed below, with links to the free online calculators on this Web site:
Erlang B
This is the most commonly used traffic model, and is used to work out how many lines are required if the traffic figure (in Erlangs) during the busiest hour is known. The model assumes that all blocked calls are immediately cleared.
Extended Erlang B
This model is similar to Erlang B, but takes into account that a percentage of calls are immediately represented to the system if they encounter blocking (a busy signal). The retry percentage can be specified.
Erlang C
This model assumes that all blocked calls stay in the system until they can be handled. This model can be applied to the design of call center staffing arrangements where, if calls cannot be immediately answered, they enter a queue.
Good luck.
Steve
Regarding Erlang:
An Erlang is a unit of telecommunications traffic measurement. Strictly speaking, an Erlang represents the continuous use of one voice path. In practice, it is used to describe the total traffic volume of one hour.
For example, if a group of user made 30 calls in one hour, and each call had an average call duration of 5 minutes, then the number of Erlangs this represents is worked out as follows:
Minutes of traffic in the hour = number of calls x duration
Minutes of traffic in the hour = 30 x 5
Minutes of traffic in the hour = 150
Hours of traffic in the hour = 150 / 60
Hours of traffic in the hour = 2.5
Traffic figure = 2.5 Erlangs
Erlang traffic measurements are made in order to help telecommunications network designers understand traffic patterns within their voice networks. This is essential if they are to successfully design their network topology and establish the necessary trunk group sizes.
Erlang traffic measurements or estimates can be used to work out how many lines are required between a telephone system and a central office (PSTN exchange lines), or between multiple network locations.
Erlang traffic models
Several traffic models exist which share their name with the Erlang unit of traffic. They are formulae which can be used to estimate the number of lines required in a network, or to a central office (PSTN exchange lines). A formula also exists to model queuing situations, and lends itself well to estimating the agent staffing requirements of call centers.
The main Erlang traffic model are listed below, with links to the free online calculators on this Web site:
Erlang B
This is the most commonly used traffic model, and is used to work out how many lines are required if the traffic figure (in Erlangs) during the busiest hour is known. The model assumes that all blocked calls are immediately cleared.
Extended Erlang B
This model is similar to Erlang B, but takes into account that a percentage of calls are immediately represented to the system if they encounter blocking (a busy signal). The retry percentage can be specified.
Erlang C
This model assumes that all blocked calls stay in the system until they can be handled. This model can be applied to the design of call center staffing arrangements where, if calls cannot be immediately answered, they enter a queue.
Good luck.
Steve
Sorry, I forgot to post the site:
www.erlang.com.
This is primarily voice modeling, but it may give you some ideas on general traffic loading.
Steve
www.erlang.com.
This is primarily voice modeling, but it may give you some ideas on general traffic loading.
Steve
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ASKER
Hi Experts!
I'm just posting a comment to say that I won't be able to check back on the questin for a couple of days, but I'll be back as soon as I can!
Anyway, thanks for your great help so far and see yah soon!
:)
I'm just posting a comment to say that I won't be able to check back on the questin for a couple of days, but I'll be back as soon as I can!
Anyway, thanks for your great help so far and see yah soon!
:)
ASKER
Back again, and sorry for the delay...
Anyway, I managed to find the info I needed not on the net, that on this kind of subjects isn't the best source but in a good book. Now, I have to close this question, since it has "almost" been answered, the more appropriate informations having been given by SysExpert.
But I cannot stop withouth saying many thanks to SteveJ for his propositions and all of other experts...
Anyway, thanks to u all!!!
:)
aCp
Anyway, I managed to find the info I needed not on the net, that on this kind of subjects isn't the best source but in a good book. Now, I have to close this question, since it has "almost" been answered, the more appropriate informations having been given by SysExpert.
But I cannot stop withouth saying many thanks to SteveJ for his propositions and all of other experts...
Anyway, thanks to u all!!!
:)
aCp
ASKER
http://ubmail.ubalt.edu/~harsham/opre640A/partIII.htm