Understanding Backplane/Throughput/Capacity

[madnirafik]

Dear Cisco Community,

I have been trying to understand from a long time about the throughput capacities of variety of Cisco Routers and Switches. Have searched over a million pages on cisco.com for data sheets/documents/etc. but havent succesfully got a single document highlighting all of what i need.

I have got queries on the below issues:

• Which model of Router can support upto 2Gig's of WAN Internet connection running BGP?
  
• Please give me list of routers and switches supporting variety of throughput's from 1 MB to 1 GB.
  
• I have heard some experts stating "Switches don't have throughput concerns as they switch the traffic and don't need to route traffic" How true is the statement?? and if it is, Why do we require 6500's instead of 3560 Distribution Switches.
  

Appreciate your swift support.

Thanks.

Kind Regards,

Madni

[ajay chauhan]

Look at diffrent model given in link below- You can easly choose what you need based on your requirment.

http://www.cisco.com/en/US/prod/collateral/routers/ps5855/prod_brochure0900aecd8019dc1f.pdf

Now answer to your last question-

Model selection depends on multiple factor - The term performance is somthing indicates PPP (Packet Per Second) processed by engine has no relation with BW.  Backplane is something related to data traffic how much data you can pass betweeen interfaces.

For example- say you have DOS attack and you have one gig internet link and you see only 50 % BW utalization but performance is real slow so PPP might cause issue and not able to process so many packets.

6500 Swicthes are used because of unique architecture DFC/ Shared Fabric so many more things which gives backplane capacity.

To know more about you need to read following links-

http://www.cisco.com/en/US/prod/collateral/switches/ps5718/ps708/prod_white_paper0900aecd80673385.html

http://www.cisco.com/en/US/tech/tk827/tk831/technologies_white_paper09186a00800a62d9.shtml

http://www.cs.cmu.edu/~srini/15-744/F02/readings/McK97.html

Thanks

Ajay

[Konstantin Dunaev]

Hello,

keep in mind the following idea :

- L3 switches can forward the traffic in hardware and the performance is limited by thier hardware parameters (ASIC performance). The lower modules have less performance then the higer model.  BUT only a cirtain, stricly defined set of features is available to be hardware forwarded. The high-end models has a wider set of feature then the low-end models.

- routers are forwardin traffic in "software", software in this case can mean that a router has just a single CPU without any hardware assistance (like cisco7200) or that the hardware assistance is so flexable that pretty ALL features are supported in hardware (like ASR).

[Konstantin Dunaev · Accepted solution]

check these two links:

http://www.cisco.com/web/partners/downloads/765/tools/quickreference/routerperformance.pdf

http://www.cisco.com/web/partners/downloads/765/tools/quickreference/switchperformance.pdf