The real meaning of "Throughput"?

[Soon Kwan Kwon]

Throughput...

I searched on the internet about it.

But I still wasn't able to understand perfectly.

For example, I saw a cisco switch has 1G throughput, but it has 24 ports (supporting 1G per port)

I think this device's total throughput 24Gbps because of sum of whole ports.

If I know this difference, I can be understanding it clearly.

Please help me guys.

Thank you.

[Mark Malone]

Throughput is the amount of packets per second or mbs per second that a device can process

So each device has a set amount of throughput its able to push through, the more services you turn on the less the throughput becomes

Taka an ASA 5505 , by default throughput is 100-150mbs per second, you turn on vpns and aes security you will be lucky to get 100mb after the packet inspections and features are on

same with an 891 router throughput around 50mb total turn on ipsec it will half it as the router is using its resources to process the ipsec

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

*******************************************************

If your switch has a 1GB throughput thats it , its split between the 24 ports like a ratio , take a blade in a 6500 chassis ws-6148 model , this has say a throughput of 16GB oin the backplane but theres 48ports so theres an oversubscription on throughput at 8:1 but bnot all ports would be processing at the same time in theory anyway

heres the definition if thats not too clear above

In general terms, throughput is the rate of production or the rate at which something can be processed. When used in the context of communication networks, such as Ethernet or packet radio, throughput or network throughput is the rate of successful message delivery over a communication channel.

[Joseph W. Doherty]

Disclaimer

The Author of this posting offers the information contained within this posting without consideration and with the reader's understanding that there's no implied or expressed suitability or fitness for any purpose. Information provided is for informational purposes only and should not be construed as rendering professional advice of any kind. Usage of this posting's information is solely at reader's own risk.

Liability Disclaimer

In no event shall Author be liable for any damages wha2tsoever (including, without limitation, damages for loss of use, data or profit) arising out of the use or inability to use the posting's information even if Author has been advised of the possibility of such damage.

Posting

Throughput has shades of meaning.  From a networking perspective, throughput generally references wire-speed or line-rate, which means how does the device perform compared to the theoretical maximum rate supported by the media.  For example, for an Ethernet gig port, can a network device generate and/or receive the maximum number of frames/packets that gigabit Ethernet supports?

Something to note, the "work" required of a network devices increases as the frame/packet gets smaller.  So, especially with older network devices, the device may only support the full "speed" of a port with frames/packets of a minimal size, or larger.  Going smaller, the device cannot support the theoretical maximum rate.

Many network devices share their performance across some or all of their ports.  If you really had a switch that only offered 1G of throughput, it would allow 1G though the device, as the aggregate of all the ports.  For example, 10 ports might have active flows of 100 Mbps each, or 20 ports of 50 Mbps each, or one port of 500 Mbps, four at 100Mbps and two at 50 Mbps each, etc.

A real example of a Cisco switch, whose aggregate performance is less than what all its ports can want, would be a 3750G-48.  It has a 32 Gbps fabric and 38.7 Mpps.  Compare that to a 4948 which has a 96 Gbps fabric and 72 Mpps (this is a wire-speed capable switch).