On Wed, 17 Jun 2020 at 22:09, <adamv0025@netconsultings.com> wrote:
From: NANOG <nanog-bounces@nanog.org> On Behalf Of Mark Tinka Sent: Wednesday, June 17, 2020 6:07 PM
I've heard a lot about "network programmability", e.t.c., First of all the "SR = network programmability" is BS, SR = MPLS, any programmability we've had for MPLS since ever works the same way for SR.
It works because SR != MPLS. SR is a protocol which describes many aspects, such as how traffic forwarding decisions made at the ingress node to a PSN can be guaranteed across the PSN, even though the nodes along the PSN path use per-hop forwarding behaviour and different nodes along the path have made different forwarding decisions. When using SR MPLS segment IDs are used as an index into the label range (SRGB) and so SIDs don't correlate 1:1 to MPLS labels, equally with SRv6 the segment IDs are encoded as IPv6 addresses and don't correlate 1:1 to an IPv6 address. There is a venn diagram with an overlapping section in the middle which is "generic SR" with a bunch of core features that are supported agnostic of the encoding mechanism. Cheers, James.