[f-nsp] CER FIB capacity

[Greg Hankins]

Hi Frank, that is correct: there is no TCAM.  SRAM access speeds are lower
than TCAM, but the tradeoff is that lookups have variable search latency.
What you probably care about most, is that both the MLX and CER can forward
Layer 3 at wire-speed for 64 byte frames regardless of the type of memory
that is used.

You can have a look at a presentation I gave recently if you want more
details on memory architectures (slides 7 and 8):
https://ripe64.ripe.net/presentations/18-ripe-64-router-architecture-challenges.pdf

Greg

-- 
Greg Hankins <ghankins at mindspring.com>

-----Original Message-----
Date: Wed, 03 Oct 2012 21:58:07 +0200
From: Frank Louwers <frank at openminds.be>
To: Greg Hankins <ghankins at mindspring.com>
CC: foundry-nsp at puck.nether.net
Subject: Re: [f-nsp] CER FIB capacity

> Greg Hankins wrote:
>> Hi Rob, the CER routers use SRAM for the IPv4/v6 FIB instead of CAM, so
>> for the CES/CER/CER-RT platforms the scalability is dynamic for all IP
>> routes in the FIB (vs the MLX CAM architecture where we have to choose
>> fixed partition sizes which can support a maximum number).
>
>
> So there is no TCAM in the CER (not even the -RT)? How much slower is an  
> SRAM lookup than a TCAM lookup?
>
> Frank
> -- 
>
> Frank Louwers
> COO Openminds
> http://www.openminds.be/
>
> Schrijf je in op onze nieuwsbrief: http://openminds.be/nieuwsbrief