[j-nsp] Use cases for IntServ in MPLS backbones

[James Bensley]

On Tue, 2 Oct 2018 at 15:11, Mark Tinka <mark.tinka at seacom.mu> wrote:
> Of course, in the real world,
> it was soon obvious that your Windows laptop or your iPhone XS sending
> RSVP messages to the network will not scale well.

A point I was trying to make way back in this thread, was that IntServ
doesn't scale well for multi-stakeholder networks, which has been my
background, ISP and managed WAN operations, so I've never deployed it.
If you have a single tenant WAN with control over the WAN *and* all
end devices you can manage the scale.

On Tue, 2 Oct 2018 at 14:38, <adamv0025 at netconsultings.com> wrote:
> And besides, I'm not sure I'd ever want to be in a position where I allow my
> core links to max out and have TE to try and shuffle flows around so that I
> can squeeze all traffic in.
> - sure this would probably not be the case of day to day operation but most
> likely only employed during link failures,

So tying this to my point above about a single-tenant WAN, this is
something that Google does (any Googler's on-list please correct where
I am wrong). They have two WANs, B2 and B4. One is public facing for
peering and transit (B2?) and the other is internal, e.g.DC to DC
(B4?). The DC to DC WAN tries to sweat it's own assets as much as
possible and run some links in the high-90's percent utilisation.
Nx100G LAGs between DCs aren't cheap, even for Google. With a single
tenant WAN you can run your links much hotter (higher average
throughput) with the aim to reduce the time spent transmitting (lower
average utilisation).

Cheers,
James.