Re: [Idr] [Can] Proposed CAN WG charter for discussion

[Peng Liu <[e-mail]>]

Hi Robert,

There might be OTT based solutions that don't involve ingress/egress routers . But some environments, like in our 5G edge network, OTT method is more expensive than a mechanism for egress routers to distribute the information to ingress routers so that path selection engines can consider both. CAN aims at the case where the operator wants to offer the selection service from its edge devices.

In the charter, 'The assumed model for the CAN WG is an overlay network, where an ingress routing node makes a forwarding decision based on the metrics of interest, and then steers the traffic to an egress node that serves the selected service instance, for example using a tunnel. Architectures that require the underlay network to be service-aware are out of scope.'

So CAN won't impact every routers but just egress and ingress, before the architecture, it is a little early to determine which protocol could be used. But for the directions, I think IETF is for building various tools. like one person can use  knife to peel an apple doesn’t mean peeler shouldn’t be invented.  

Regards,
Peng


[e-mail]
 
From: Robert Raszuk
Date: 2023-01-28 05:35
To: Linda Dunbar
CC: John Scudder; [e-mail]; [e-mail]; [e-mail]
Subject: Re: [Can] [Idr] Proposed CAN WG charter for discussion
Hi Linda,

But why do we need to do that within the underlay network vs Over The Top (OTT) way ? 

Why network needs to be at all involved in distribution of the load information if we could solve it at the application level and keep network lean and as much stateless as possible ? Simple mapping plane will work just fine for this resulting in OTT Compute Aware Load Balancer (for the lack of the better name). 

Why bring this "awareness" to BGP or IGP or even routers in general ? 

Isn't the draft https://www.ietf.org/id/draft-kjsun-lisp-dyncast-03.html a possible solution ? 

Many thx,
R.


On Fri, Jan 27, 2023 at 9:43 PM Linda Dunbar <[e-mail]> wrote:
John, 

Oh, I guess I have over-thought of the "Architecture & framework". 
The proponents' wanting a mechanism for egress routers to distribute computing resources to ingress routers can be considered as one rough architecture. 

Thank you. 

Linda

-----Original Message-----
From: John Scudder <[e-mail]> 
Sent: Friday, January 27, 2023 12:06 PM
To: Linda Dunbar <[e-mail]>
Cc: [e-mail]; [e-mail]; [e-mail]
Subject: Re: Proposed CAN WG charter for discussion

Hi Linda,

I didn't mean to say that the architecture would have to be completed to the point of RFC publication before that step could be started! But of course, anyone studying the applicability of a mechanism, has to be thinking, "applicable for what purpose"? So I think that studying applicability presupposes that the person doing the study has an architecture in mind. 

Your summary seems about right, and I think it demonstrates that those in the side discussion *do* have at least a rough architecture in mind. My point is,

a. It's important to write that rough architecture down, to make the assumptions transparent to all WG participants, and b. It's important that when listing work items, we do not lose sight of the fact that this is one work item.

I don't see the bullet list as comprising a strictly ordered list of tasks that have to be completed in the order listed, I'm sure some will be worked on in parallel or even out of order. 

I hope that helps?

-John