[c-nsp] Cisco N540-ACC-SYS ipv4 routes

Radu-Adrian FEURDEAN cisco-nsp at radu-adrian.feurdean.net
Sun Jul 12 05:44:43 EDT 2020



On Sat, Jul 11, 2020, at 21:34, Saku Ytti wrote:
> 
> But what is software based and what is hardware based? To me ASR1k is

Put this way, everything is both software based and hardware based, since there is software running on hardware. Jusy than when using an ASIC, the software part is not doing very much for the packet switching. 

> HW based, it's an NPU box in my mind.  
> Not having TCAM does not
> exclude box from being hardware, if not having TCAM means it's not
> hardware,

You're right. However, moving away from TCAM usually signals chipsets more complex than ASICs (=more important software component). 

>  then also say Juniper MX, PTX are not hardware, Cisco 8k is
> not hardware, Jericho2 isn't hardware, modern stuff tends to run off
> of DRAM, not TCAM.

Most of them can definitely do more than dumb  packet forwarding, but not so much as to do LNS or CGN in the main NPU (whatever variety the NPU is). A1k OTOH is THE platform to be used if you want to do LNS and CGN with Cisco. 

As for TCAM vs *RAM, lack of TCAM signals a FIB scale significantly larger than a full table at the moment the box was designed. 

Back to the question, NCS540 is merchant ASIC, while A1K is custom network-oriented processor. I'd expect FIB scale to be a few (~4-5) times higher on A1K than on NCS540. 

-- 
R.-A. Feurdean


More information about the cisco-nsp mailing list