Re: [Roll] Alvaro's review on turnon Rfc 8138 07

[Rahul Jadhav <[e-mail]>]

<Pascal>
Right. The document aims at enabling RFC 8138 in a brown field. The *normal* scenario is migrate slowly the nodes with the bit off and when all are migrated turn the bit on. The complex case is that of "forgotten nodes", e.g., nodes for which there was never a new code for this draft and for the compression, to try to serve them still. Imagine a network where thousands of meters out of millions are from an old brand that can never be upgraded. Can we replace them? Probably not. So do we live with the idea that the compression can never be turned on in the whole network?

That's the big question to the group, is that a valid use case. Because if it is, we do not want to have to do yet another draft do we?
</Pascal>

<Rahul>
Even if there are thousands of nodes from an old brand, they will be within their own FAN (Field Area Network). The compression decision is on per Border-Router/Root level i.e., usually at a FAN level. Point is, all the millions shouldn't be impacted. My experience says that the firmware/meters in a given FAN are upgraded simultaneously. If a FAN contains a mix of old and new then it can continue using the uncompressed form.

I wish we could support all three types of leaves in the same network: RULs, RAL supporting compression, RAL not supporting compression, and all of this in both storing/non-storing. I also understand that the only problem case is the leaves in storing mode since the knowledge of last-hop is not known. But without additional changes in terms of introducing more fields, it may not be possible to handle this. The problem with these additional fields is that they will be redundant once we have capabilities.

I feel we do not need to handle the case of "forgotten nodes".
</Rahul>