Throughput vs Backplane in Cisco 6500.

[sachin_sharma0021]

What is difference between Throughput & Backplane.

Can anybody send the Chart in which throughput/Backplane is mentioned of Cisco 6500, 4500, 3750 ???

[Shashank Singh · Accepted solution]

Hi Sachin,

Throughput is the bandwidth being used in terms of bits/sec. Backplane is the internal common bus which is used by interfaces to communicate between different line cards on the same switch. They are not directly related terms.

However, backplane has a maximum throughput which varies on every platform. Are you trying to find out the the maximum throughput of the backplane?

Regards,

Shashank

Please rate the answer if the content was useful

[Amit Singh · Accepted solution]

Sachin,

The earlier poster has already mentioned the throughput/backplane.

The 6500 has a cross-bar fabric architecture. It has got two backplanes

1.Shared bandwidth of 32Gbps

2.A  bandwidth with allow access to the switch fabric.eg,SUP 720 gives  2X20  Gpbs bandwidth to acccess its inbuild swithcing matrix..

A switching fabric is the combination of hardware and software that  moves data coming in to a network node out by the correct port (door) to  the next node in the network. A switching fabric includes the switching  units in a node, the integrated circuits that they contain, and the  programming that allows switching paths to be controlled. The switching  fabric is independent of the bus technology and infrastructure used to  move data between nodes and also separate from the router. So depending upon the switching fabric you are using, he catalyst 6500 has different backplane throughputs.

1. If you are using SFM (Switch fabric module), you can upscale the backplane to 256 Gbps system throughput.

2. If you are using Sup720's which has integrated switch fabric, you can upscale the system throughput 720Gbps with 2x20 Gbps channels per slot with DFC's.

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

The Catalyst 4500 is a centralized architecture meaning that all the line cards connects to the SUP directly via backplane for processing. All the switching decisions are being made by the Supervisor engine. So depending upon the supervisor you are using you will get a dedicated per slot bandwidth for the line cards. As most of the older SUP's are EOS/EOL  you have the following options depending upon the chassis you are using :

1. SUP6L-E, which provides 280Gbps switching capacity with 24Gbps /slot bandwidth in 4506E/4507R-E chassis

2. SUP6-E, which provides 320Gbps switching capacity with 24Gbps/slot in 4510R-E with last 3 slots providing only 6Gbps/slot.

3. SUP7-E, which provides 888 Gbps switching capacity with 48Gbps/Slot in 4510R+E chassis.

http://www.cisco.com/en/US/prod/collateral/switches/ps5718/ps4324/product_data_sheet0900aecd801792b1.html

http://www.cisco.com/en/US/products/hw/switches/ps4324/prod_models_comparison.html

The 3750 switch is a fixed config switch and depending upon the module you are using have different maximum backplane throughput.

1. 3750 - Maximum 32 Gbps

2. 3750-E Maximum 128 Gbps

3. 3750-X - Maximum 160 Gbps.

http://www.cisco.com/en/US/prod/collateral/switches/ps5718/ps6406/data_sheet_c78-584733.html

HTH, Please rate if it does.

-amit singh

[Nathan Spitzer]

One minor detail, in a 3750 stack all frames pass through the stacking ring, therefore the backplane of a 3750 stack is one times the slowest member. So if you have a stack of 4x 3750-x and one 3750 the maximum backplane speed is 32Gb.