why am i in this handbasket? (was Devil's Advocate - Segment Routing, Why?)

Mon Jun 22 13:49:54 UTC 2020

> From: Masataka Ohta <mohta at necom830.hpcl.titech.ac.jp>
> Sent: Monday, June 22, 2020 2:17 PM
> 
> adamv0025 at netconsultings.com wrote:
> 
> > But MPLS can be made flow driven (it can be made whatever the policy
> > dictates), for instance DSCP driven.
> 
> The point of Yakov on day one was that, flow driven approach of Ipsilon
does
> not scale and is unacceptable.
> 
> Though I agree with Yakov here, we must also eliminate all the flow driven
> approaches by MPLS or whatever.
> 
First I'd need a definition of what flow means in this discussion are we
considering 5-tuple or 4-tuple or just SRC-IP & DST-IP, is DSCP marking part
of it? 
Second, although I agree that ~1M unique identifiers is not ideal, can you
provide examples of MPLS applications where 1M is limiting?
What particular aspect?
Is it 1M interfaces per MPLS switching fabric box?
Or 1M unique flows (or better flow groups) originated by a given
VM/Container/CPE?
Or 1M destination entities (IPs or apps on those IPs) that any particular
VM/Container/CPE needs to talk to?
Or 1M customer VPNs or 1M PE-CPE links, if PE acts as a bottleneck?

adam