RE: few big monolithic PEs vs many small PEs

[<adamv0025 () netconsultings com>]

> From: Mark Tinka
> Sent: Friday, June 21, 2019 9:07 AM
>
>
>
> On 21/Jun/19 09:36, adamv0025 () netconsultings com wrote:
>
> > And indeed there are cases where we connect customers directly on to
> > the PEs, but then it's somehow ok for a line-card to be part of just a
> > single chassis (or a PE).
>
> We'd typically do this for very high-speed ports (100Gbps), as it's cheaper to
> aggregate 10Gbps-and-slower via an Ethernet switch trunking to a router line
> card.
>
>
> > Now let's take a step even further what if the line-card is not inside the
> chassis anymore -cause it's a fabric-extender or a satellite card.
> > Why all of a sudden we'd be uncomfortable again to have it part of just a
> single chassis (and there are tons of satellite/extender topologies to prove
> that this is a real concern among operators).
>
> I never quite saw the use-case for satellite ports. To me, it felt like vendors
> trying to find ways to lock you into their revenue stream forever, as many of
> these architectures do not play well with the other kids. I'd rather keep it
> simple and have 802.1Q trunks between router line cards and affordable
> Ethernet switches.
>
> We are currently switching our Layer 2 aggregation ports in the data centre
> from Juniper to Arista, talking to a Juniper edge router. I'd have been in real
> trouble if I'd fallen for Juniper's satellite system, as they have a number of
> shortfalls in the Layer 2 space, I feel.
I'd actually like to hear more on that if you don't mind.

> > So to circle back to a standalone aggregation device -should we try and
> complicate the design by creating this "fabric" (PEs "spine" and aggregation
> devices "leaf") in an attempt to increase resiliency or shall we treat each
> aggregation device as unitary indivisible part of a single PE as if it was a card in
> a chassis -cause if the economics worked It would be a card in a chassis?
>
> See my previous response to you.
You actually haven't answered the question I'm afraid :)
So would you connect the Juniper now Arista aggregation switch to at least two PEs in the POP (or all PEs in the POP 
-"fabric-style") or would you consider 1:1 mapping between an aggregation switch and a PE please?

adam