[c-nsp] PE "Sprawl" - P/Core Router suggestions.

[adamv0025 at netconsultings.com]

> Phil Bedard
> Sent: Saturday, December 31, 2016 1:17 AM
> 
> It’s all VoQ based so it’s similar to other VoQ-based hardware, so there is no
> such thing as an “egress” drop.  There is an ingress traffic manager stage early
> in the pipeline that does most of the work.  On the fabric based systems
> there is a request/grant paradigm for fabric access.  At an early point in the
> pipeline it can do packet replication, which is where mirroring and netflow
> come into play.
> 
I guess you mean ingress queueing based, rather than VOQ-based, (for example ASR9k is also VOQ-based but uses also egress delay BW buffers). 
But regarding the pre-classification, would you please know how many priority levels it has and whether it can be altered via CLI and what type of scheduling is used between the pre-classifier queues towards the NPU pipeline? 
Regarding the backpressure, does it actually react to NPU oversubscription, or is the grant rate just statically set to nominal NPU BW rate please? 
On the non-modular boxes, or on a single LC, how are the NPUs interconnected? I guess these are using shared memory architecture? 

Would you folks know whether Xander has NCS5K platform under his wings as well? 

adam   

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