----- On Jun 20, 2020, at 2:27 PM, Mark Tinka <mark.tinka@seacom.mu> wrote: Hi Mark,
On 20/Jun/20 00:41, Anoop Ghanwani wrote:
One of the advantages cited for SRv6 over MPLS is that the packet contains a record of where it has been.
I can't see how advantageous that is,
That will be very advantageous in a datacenter environment, or any other environment dealing with a lot of ECMP paths. I can't tell you how often during my eBay time I've been troubleshooting end-to-end packetloss between hosts in two datacenters where there were at least 10 or more layers of up to 16 way ECMP between them. Having a record of which path is being taken by a packet is very helpful to determine the one with a crappy transceiver.
or how possible it would be to implement,
That work is already underway, albeit not specifically for MPLS. For example, I've worked with an experimental version of In-Band Network Telemetry (INT) as described in this draft: https://tools.ietf.org/html/draft-kumar-ippm-ifa-02 I even demonstrated a very basic implementatoin during SuperCompute 19 in Denver last year. Most people who were interested in the demo were academics however, probably because it wasn't a real networking event. Note that there are several caveats that come with this draft and previous versions, and that it is still very much work in progress. But the potential is huge, at least in the DC.
especially for inter-domain traffic.
That's a different story, but not entirely impossible. A probe packet can be sent across AS borders, and as long as the two NOCs are cooperating, the entire path can be reconstructed. Thanks, Sabri