[c-nsp] Devil's Advocate - Segment Routing, Why?

[Benny Lyne Amorsen]

Saku Ytti <saku at ytti.fi> writes:

> This is simply not fundamentally true, it may be true due to market
> perversion. But give student homework to design label switching chip
> and IPv6 switching chip, and you'll use less silicon for the label
> switching chip. And of course you spend less overhead on the tunnel.

What you say is obviously true.

However, no one AFAIK makes an MPLS switch at prices comparable to basic
layer 3 IPv6 switches. You can argue that it is a market failure as much
as you want, but I can only buy what is on the market. According to the
market, MPLS is strictly Service Provider, with the accompanying Service
Provider markup (and then ridiculous discounts to make the prices seem
reasonable). Enterprise and datacenter are not generally using MPLS, and
I can only look on in envy at the prices of their equipment.

There is room for a startup to rethink the service provider market by
using commodity enterprise equipment. Right now that means dumping MPLS,
since that is only available (if at all) at the most expensive license
level. Meanwhile you can get get low-scale BGPv6 and line-speed GRE with
commodity hardware without extra licenses.

I am not saying that it will be easy to manage such a network, the
tooling for MPLS is vastly superior. I am merely saying that with just a
simple IPv6-to-the-edge network you can deliver similar services to an
MPLS-to-the-edge network at lower cost, if you can figure out how to
build the tooling.

Per-packet overhead is hefty. Is that a problem today?