[AusNOG] Cisco routers on NBN 100/40Mbps connection

[Chris Lee]

Does anyone have any experience with Cisco 1812 and running it on a 50M/50M
ethernet circuit ?

Looking at that Cisco router performance sheet shows the 1812 only good for
35Mbps, we've currently got one on the end of an Optus Evolve 20M/20M
service which just passes most of the traffic straight through to an
ASA5520 behind it, however the 1812 does also terminate and handle a
microscopic amount (ie: 20-30kbps) of IPSec site-to-site VPN traffic...

The CPU load on the router spikes up to around 12% utilisation when we run
the link at 20M, so if that scales up reasonably linearly then running at
50M should still be under 50% CPU ?

Thanks,
Chris

On Sun, Aug 10, 2014 at 11:11 AM, Reuben Farrelly <reuben-ausnog at reub.net>
wrote:

> On 10/08/2014 10:53 AM, James Jazza wrote:
>
>> Hi Guys,
>>
>> We are hearing reports that Cisco 881 routers are not suitable for NBN
>> 100/40Mbps connections, and that we need to use the next model up - a
>> Cisco 1841 instead.
>>
>
> The 1841s are approaching end of life.  You will want to look at a 1921 or
> 1941 for this or even higher, depending on what features you want to
> enable.  Not only because of the throughput increase that you'll need, but
> it doesn't make much sense to deploy 10 year old hardware on a new link..
>
>
>  Can anyone comment on this? As the Cisco 881 has 100Mbps internal ports,
>> so I would have thought it would be ok.
>>
>
> A 100M port line rate does not indicate, or even suggest, 100M of routing
> throughput.
>
> Generally speaking on a L2/L3 switching platform you will get line rate
> between switched ports, as the switching is done in hardware.
>
> But on a router where you're doing routing on a software based platform
> where the CPU is heavily involved in packet forwarding, the forwarding
> numbers are almost always much much lower than port line rate.
>
> The 881/1800/1900/2900/3900s are for the most part software based routers
> where the limiting factor in terms of throughput is the CPU speed and
> utilisation.
>
> This document is very out of date (last update November 2009) but it's a
> good relative comparison between platforms, as to what you may be able to
> get:
>
> http://www.cisco.com/web/partners/downloads/765/tools/quickreference/
> routerperformance.pdf
>
> Reuben
>
>
>
> _______________________________________________
> AusNOG mailing list
> AusNOG at lists.ausnog.net
> http://lists.ausnog.net/mailman/listinfo/ausnog
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.ausnog.net/pipermail/ausnog/attachments/20140815/00a609cf/attachment.html>