Where do I get the formulas?

[debumohit]

Hi everybody,

I am very new to TCP implementations and I am working on Congestion control/avoidance mechanisms. I want to find more descriptive information about the TCP measurements and the relevant graph plotting techniques. Can anybody help me?

Thanks,
Mohini

What worth is freedom if it does not include the freedom to make mistakes!

 

[Comstocb]

The question is really too general to answer as each environment is different but a good place to start is with MRTG (freeware on the net) that gathers SNMP data from your switching/routing equipment and generates graphs of utilization over the long term. I use it to understand the dynamics of my environment and if traffic patterns are changing in a direction that will require additional resources/bandwidth. Its a web based trending tool that has shown me that my gigabit backboned environment isn't even close to being taxed. QOS for VOIP, I implemented it here before I started using MRTG and now I know it is serving zero purpose since I never even come close to the utilization numbers where traffic queueing makes a difference. I have even used it to identify faulty servers dumping loads of useless traffic on my network driving my network utilization numbers up beyond whats normal. Of course, I only new what normal was because of MRTG. Guess I am trying to say I can't recommend it enough.

Brian

 

[debumohit]

Hi Brian,

Thanks for the tips. I have heard about MRTG myself. But my problem is that I'm running simulations on the Network Simulator and don't have particular network devices on which I intend to measure the properties. I started with NS on Windows 2000 and am using a basic dumbbell topology; with n TCP flows, a router and a sink. Now I want to change certain parameters like queue size, delay, etc and relate the results. Can I make use of MRTG here? I guess not.

So basically I want to generate various graphs with various values for the parameters and for that I need to know the exact way of measuring (in a simulation) network properties. Can you help me with that? Thanks a lot.

Mohini

 

[pansophic]

Have you looked at OPNET? Last I saw, I believe that it did exactly what you are looking for. I thought it included device characteristics for many of the more popular network components, and you could simulate traffic and configuration issues based on different configurations.

Take a look at:

http://www.opnet.com/products/modeler/

pansophic

 

[debumohit]

Hi Pansophic,

Thanks for the URL.

Mohini.