[robjs]

SRv6 is not going to transform the quality of experience/quality of service that you see from Internet applications. Traffic engineering technologies like this (MPLS-based, IP-based, emulated circuit based...) are used inside networks to select paths through them, this has been done for many years, and the segment routing data-plane - whether it be MPLS or IPv6, is a different realisation of how to achieve that path selection through a network. There are networks that have done this traffic engineering using IP encapsulation for many years.

The whole "IP 2.0" presumption that appears to be being made here is that suddenly some external traffic source will be able to select a route through someone else's network -- but this just isn't the commercial reality. Some more performant paths are going to have costs associated with them (even if it's just to build more capacity), so there is going to be a cost of choosing that route through the network. That cost is going to need to be covered somewhere - so you are very unlikely to actually be able to get to choosing a path without some commercial contract. Guess what? We've already had those -- they just tend to use the DSCP bits to indicate what the traffic class, and hence associated requested SLO is - not an explicitly chosen path.

Equally, let's think about how this would even work - if you are going to choose a path through the network to get better QoS, you're going to need to know something about what IDs to use, which implies knowledge of the topology. Inter-domain topology exposure is going to /significantly/ increase the complexity and fragility of inter-domain routing -- there are reasons that we don't run a global link-state protocol :-)

In conclusion - I think this is hype with little technical justification, and is unlikely to have any different impact than other intra-domain traffic engineering that the industry has been running for many years.

[teleforce]

Yes sure MPLS works as combustion engines work as long we can remember, but it's not stopping EV as a new contender as the near future vehicle platform whether we like it or not. Now we have hybrid MPLS or SR-MPLS as a stopgap measure similar to what we have now with PHEV, etc. Personally I think the networking industry has already learned their mistakes from the ATM days and hopefully SRv6 will take off for better and more effective IP based networking.

[robjs]

I don't understand what this means. This was not a defence of MPLS, but rather an observation that says that the fundamental domains and business logic around externally-selected TE paths do not change because we change what header instructs the network to steer packets. It's still not going to make sense to have external users try and use the "premium" paths in the network without some recompense to keep scaling them, equally, there needs to be some incentive for users to choose a "less than best" path.

Quite honestly -- this kind of marketing hype and hyperbole is what is wrong with the whole area of SR today (and I say this as someone that was _very_ involved). We've completely lost the ability to say what it is we're solving, and why we're doing it. We're driving disparate architectures into silicon where there's opportunity cost for the functionality. We're having political disagreements within the IETF based on folks trying to keep political control of technologies, not worrying about the efficacy for the industry. It's all pretty broken. YMMV.

[teleforce]

Let's us step back and look into the current mess of the existing IP networks with all the duct tapes involved (looking at you NAT). Any QoS that the end users probably want is only make dollar sense for the big companies that's why we have the fine print of best-effort services written in almost all the Telcos' EULA. What IPv6 based technology for example SRv6 is doing is trying to democratize QoS so that it's hopefully affordable to the average Joe. Perhaps it's still a pipe dream at the moment but given the current situations I will take SRv6 over MPLS, or any expensive TE any day. My networking utopia will be a local-first software with cloud vendors and Telcos independence that can utilize the networks based on their required and necessary QoS. I foresee that the best way of going forward is based on this new promising and more affordable technology that the incumbent technology cannot provide.

[fach]

Can we not step back and instead address the practical implementation challenges robjs raised?