External BGP Controller for L3 Switch BGP routing

Tore Anderson tore at fud.no
Mon Jan 16 06:40:47 UTC 2017

Hi Saku,

> > https://www.redpill-linpro.com/sysadvent/2016/12/09/slimming-routing-table.html
> ---
> As described in a prevous post, we’re testing a HPE Altoline 6920 in
> our lab. The Altoline 6920 is, like other switches based on the
> Broadcom Trident II chipset, able to handle up to 720 Gbps of
> throughput, packing 48x10GbE + 6x40GbE ports in a compact 1RU chassis.
> Its price is in all likelihood a single-digit percentage of the price
> of a traditional Internet router with a comparable throughput rating.
> ---
> This makes it sound like small-FIB router is single-digit percentage
> cost of full-FIB.

Do you know of any traditional «Internet scale» router that can do ~720
Gbps of throughput for less than 10x the price of a Trident II box? Or
even <100kUSD? (Disregarding any volume discounts.)

> Also having Trident in Internet facing interface may be suspect,
> especially if you need to go from fast interface to slow or busy
> interface, due to very minor packet buffers. This obviously won't be
> much of a problem in inside-DC traffic.

Quite the opposite, changing between different interface speeds happens
very commonly inside the data centre (and most of the time it's done by
shallow-buffered switches using Trident II or similar chips).

One ubiquitous configuration has the servers and any external uplinks
attached with 10GE to leaf switches which in turn connects to a 40GE
spine layer with. In this config server<->server and server<->Internet
packets will need to change speed twice:


I suppose you could for example use a couple of MX240s or something as
a special-purpose leaf layer for external connectivity.
MPC5E-40G10G-IRB or something towards the 40GE spines and any regular
10GE MPC towards the exits. That way you'd only have one
shallow-buffered speed conversion remaining. But I'm very sceptical if
something like this makes sense after taking the cost/benefit ratio
into account.


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