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

[Mark Tinka <mark.tinka () seacom mu>]

On 18/Jun/20 02:32, Phil Bedard wrote:
> I look at the basic SR via IGP extensions like VPLS vs. EVPN.   If we had a way to go back in history I'm not sure 
> anyone would have said VPLS was a good idea vs. EVPN.  
>
> There were reasons back in the day why something like SR wasn't done.  The thought of global MPLS labels scared 
> people and source routing was also evil.  So LDP was created to distribute labels hop by hop, while still relying 
> 100% on the IGP to do so.  It kind of defies common sense when you look at it now, but there were supposedly good 
> reasons for it back then.  
>
> SR-MPLS on an existing device supporting MPLS forwarding is a control-plane change, meaning almost any device could 
> support SR-MPLS.  
>
> SR is meant to be data plane agnostic, the SID is just an identifier.  Most support MPLS, some support IPv6.  

Fair enough.

There's still a whole IGP mess to sort out though, not to mention many
years of field experience to bake in.

Mark.