Re: [homenet] Routing protocol comparison document

[Ray Hunter <[e-mail]>]

Mark Townsley wrote:
>
> Dear WG,
>
> In Hawaii, Margaret offered to pull together a document providing a 
> summary of ISIS and Babel within the context of homenet. Working with 
> Chris Hopps and Juliusz Chroboczek, Margaret just posted 
> draft-mrw-homenet-rtg-comparison-01.txt. Many thanks to all 3 authors 
> for this input, I'm sure it will help the WG make a more informed 
> decision.
>
> While there was a great deal of discussion and collaboration amongst 
> the authors, this document does not represent the authors' consensus 
> in its current form. This document is not intended to make a final 
> recommendation one way or another at this time, rather it is a 
> starting point for those who want more information but do not want to 
> dive into the entire repertoire of documents (or code) for ISIS or Babel.
>
> As such, I would like to invite everyone to use this as a starting 
> point to familiarize yourselves with these two options. State your 
> questions, comments, and opinions with at as much lively debate as we 
> heard at the microphone and in the hallways in Hawaii.
>
> Thank you,
>
> - Mark
>
>
I have read this draft, as well as the WG discussion up until 18/2. 
Thanks to the authors for compiling this document.

I think there are still several clarification/improvement points to be 
made, even if we assume that this draft will never be published/serve as 
a useful reference beyond the life of the WG.

Section 4. seems to be largely irrelevant as currently written as far as 
I can see.

What would interest me more is whether there is a practical difference 
in behaviour given an unstable link in the Homenet network e.g. a 
powerline link that suffers from interference and bounces regularly.

Does IS IS behave differently to Babel when one link is unstable in the 
Homenet?

Is the forwarding freeze during link-state calculation at all 
significant, given the claimed convergence times?

Is there a significant difference in the (native) detection of neighbor 
down between the two protocols?

Or do they rely heavily on interface/link/carrier down?

I also don't currently see anything about interfaces to low power devices.

Is there a significant difference between Babel and IS IS behaviour in a 
completely stable network, especially with respect to battery life?

Section 12.

 >  The code size of IS-IS depends greatly on what aspects of the 
protocol have been implemented.


When talking about IS IS, I'm not entirely sure what we would be 
importing into Homenet if we did a #include IS-IS , and also what 
incompatibilities that might generate given multiple implementations 
with varying feature sets.

This comment has already been raised by others and I agree it requires 
further clarification. Exactly which feature set of IS IS are we talking 
about?

I also think there should also be more explicit links back into the 
Homenet Architecture document 
https://datatracker.ietf.org/doc/rfc7368/?include_text=1.

Especially section 3.5 where we agreed requirements for the routing 
protocol.

Perhaps a table with "complies" "does not comply" or "partially 
complies" per paragraph or phrase?


I'd also be interested in reading about the practicality of my 
smartphone being able to participate as a (stub) Homenet router. I think 
that's a nice use case for "running code."

Would I need to jailbreak my phone to be able to load IS IS? or Babel? 
Especially re: access to operating system APIs?

If it's not there today, how difficult would it be for a 3rd party App 
Developer to build such a solution?

Or would users have to depend on the phone manufacturer incorporating 
Homenet out of the shrink wrap?

-- 
Regards,
RayH