[c-nsp] 'Number of Routes' Vs Ram

[Oliver Boehmer (oboehmer)]

Drew Weaver <> wrote on Sunday, March 12, 2006 9:36 AM:

> 	Howdy, I realize that there is a direct correlation between the
> number of routes a service provider receives from their transit
> provider and peers and how much ram they will need for their routers.
> Has anyone actually ever tried to figure this out actual numbers on
> this? We are getting full routes from about 5 carriers split in more
> than one router at the moment and at times it can be a little dicey
> with 256MB of ram (the BGP router process uses quite a bit of
> processor memory at times) and it is leading us to upgrade to 512MB,

512MB on the RP is definitly recommended these days. The amount of
memory not only depends on the number of prefixes, but also the number
of different paths for any given prefix. So it makes a big difference if
you receive 200k prefix from only one peer or from several ones.

> I am wondering if we may be better off upgrading from the 12012s that
> we are using to 12812s or at least 12412s altogether.

Well, these chassis mainly differ in their fabric bandwidth. So unless
you also upgrade linecards and need the 10G or 40G fabric, a DRAM
upgrade on the RP (GRP/PRP) and possible route memory upgrade on the LC
(we generally recommend half of the RP DRAM) will do just fine in your
12012.

	oli