Network Availability Average Reconnect Time

[danmartinnorhrop]

Hello,

I have been spending the past few hours trying to find information on a question I was asked.  The question is, "what is the average connect/reconnect time on an average Cisco Network device?  Being an engineer myself I understand this is a very bad question as it is often application dependent and there are other variables to consider which I tried to explain to this person.  Anyhow, I was hoping someone with more networking experience could point me to a resource that may have "some kind of reasonable answer" I can give to this person.

Thanks in advance for your help,

Joe

[Georg Pauwen]

Joe,

to be honest, I don't understand the question. I know when you get a question like that, and being a network engineer, you want to give a reasonably intelligent answer, but I would go back to the person that asked the question and clarify what they are after. MTBF (Mean Time Between Failure) ? That is something that is documented, by device...

But connect/reconnect ?

[danmartinnorhrop]

Hey Georg,

Well, what I have been doing so far is trying to come up with a "rough guess" based on some Cisco facts that show how fast a packet can get processed and pushed out of a router device.  I think he does not entirely know what he wants and I figure if I can give him something or some answer he will either be content or can use that to better refine his question instead of me asking him more questions which I already tried and he was getting annoyed and frustrated.

So do you know of any general facts that might show or give an idea of how fast packets get processed?  I found this link

http://www.cisco.com/c/en/us/products/collateral/routers/asr-1000-series-aggregation-services-routers/white_paper_c11_517185.html

But it is based on performance tests and I guess I was hoping there might be a specification data sheet that might have more general information that I can more easily use.  Perhaps you might know where I can find this?

Thanks,

Joe

[Georg Pauwen]

Joe,

there used to be routing and switching performance sheets like the ones linked below, but since performance depends on different factors, the best place is to look for the data sheets of the specific model you are interested in. Here is an example:

Cisco Integrated Services Routers—Performance Overview

https://supportforums.cisco.com/sites/default/files/attachments/discussion/white_paper_c11_595485_3.pdf

Portable Product Sheets – Routing Performance

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

Portable Product Sheets – Switching Performance

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

Hope that helps you at least a little bit further...

[Joseph W. Doherty]

Like Georg, your user's question's intent is unclear.

If your user is looking for packet processing time, there wouldn't be a real average as so much will depend on the hardware capabilities of the device and what the devices is configured to do.  However, in general, processing time, per packet, should usually be sub millisecond.

For any device that claims "line rate", processing time per packet should be less than a packet's transmission transfer time, otherwise, "line rate" won't be maintained.

[r-godden]

For a multicast application over a routed network , the reconnect process can take 3 minutes.