[c-nsp] 1841 suitable for BGP?

[Joe Maimon]

Pete Barnwell wrote:
> Hi,
> 
> I'm looking at a router to handle 2 x 10Mb/s (ethernet) feeds and take a
> full BGP routing table from both ISPs. Will an 1841 with 384Mb suffice
> for this, or do I need to look at higher spec models?
> 
> Pete
>

The 1841 is documented to do 75k pps at 64bytes for 38.4 mbps

This should cover 2 10mbps full duplex.

If you expect to push larger packets you might feel free to rerun the 
calculation, but if reality proves you wrong, you have no one to blame 
but yourself.

On the other hand, if you follow the algorithm offered here previously 
in a post from <i cant find it> and divide by half the documented number 
for every feature used, including the act of booting IOS, you might want 
something with more headroom.

To completely bypass port density issues, I would recommend you pair the 
1841 with a 2950 switch and do dot1q. No need to worry about ethernet 
ports now.

384 should be more than sufficient for two feeds for the forseeable 
future, seeing as how people are still squeezing 2 feeds into 256 
(granted, thats probably with different IOS trains).

CPU usage by the BGP process is not supposed to affect packet forwarding 
in interupt context. Slow reconvergence by CPU could affect routing 
recovery after outages, but odds that this would affect you and to what 
extent is probably not very high.

So yes, it is likely as not to "suffice", at least for the near 
forseeable future.

The better question is how much of a guarantee that it will suffice are 
you looking for?