[c-nsp] Curious... 2800 or 3800

[Gert Doering]

Hi,

On Mon, Apr 02, 2007 at 06:10:40PM -0500, Justin Shore wrote:
> That's 520Mbps of 64 byte packets on a NPE-G1 *doing absolutely nothing 
> else.*  No ACLs, NAT, PPPoE, EGP, IGP, NetFlow, NBAR, SNMP, uRPF, CoPP, 
> QoS, CAR, logging of any kind, heaven forbid any crypto, etc, yadda, 
> yadda.  Not even someone sitting on the console running sh proc cpu to 
> monitor the load (pull the 5min avg instead).  Everything done in HW and 
> virtually nothing switched across the CPU.  

There is no "HW" in a NPE-G1 that could switch packets.  

It's always the CPU - but could be "fast path in CEF" or "slow path
in 'IP input' process".

</nitpick>

> Nothing a router under a 
> normal workload in a normal configuration would be doing.  That's how 
> it's been explained to me.  I've even seen an SE jot down some figures 
> on a napkin that basically showed how ASIC XYZ has a bus ABC wide.  At 
> DEF Mhz it can process a header in GHI amount of time which means it can 
> process JKL headers per second.  Assuming a minimum size payload of MNO 
> the ASIC can switch amount of data at a rate of PQR per second. 

Interesting calculation, but it certainly wasn't for the NPE-G1 (which
has no ASICs that would switch packets).

Maybe you're confusing this with the NSE-1 or other PXF-based platforms?

> Assuming that the CEF entry had already been made and that there wasn't 

CEF entries are not made "on-demand".

gert
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Gert Doering - Munich, Germany                             gert at greenie.muc.de
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