Subject: RE: [Monami6] new revised charter

From: [email-masked]
Date: Tue, 13 Sep 2005 09:44:29 +0300

Marcelo, 

>well, as i stated before, imho fault tolerance is an important 
>part of the support of multiple tunnels, in particular the 
>capability of detecting outages and selecting the tunnel that 
>is working. In addition i think is within the scope of the 
>proposed work, i.e. the support of multiple CoAs and multiple 
>HA addresses, i.e. if you want to support multiple CoAs you 
>should try to provide the fault toleracen features that they enable.
>
>I guess we should hear what other folks think about this point.

Depending upon what CoAs you have, it might be good to have someway
of influencing which CoA is the 'active' CoA.  This might be from
some policy or the MN and/or HA could express which is the default
and which is the prefered backup CoA, for example.  

I think Thierry is saying that we need to document what we want to
do before deciding if we use the BU/Back or ICMP echo for testing
aliveness.  Actually, I wouldn't like to see mandating any liveness
test, especially over wireless links, as this could be performance
hit (especially from the power consumption point of view) if this
test was run often. I'd probably like to list 'hints' that the HA or 
MN could use to determine if a CoA is live or not.

Nicolas said:

 "The WG will not work on tunnel selection based on dynamic discovery of

 tunnel characteristics, but will assume that it is given by policy or
other 
 mechanisms external to the Monami6 work. In particular, the WG will
consider 
 that a tunnel is alive as long as BU/BACK can be exchanged with the
corresponding 
 peer. In addition, local information, such as an interface went down,
can be 
 used to quickly detect failure of tunnel(s)."

I'd suggest

 "The WG does not plan on creating a tunnel selection mechanism, but may
document
 how to use existing mechaims based upon preferences or policies for
this. In particular, 
 the WG will consider that a tunnel is alive as long as packets can be
exchanged with the 
 corresponding  peer. In addition, local information , such as an
interface went down, 
 or other failure detection mechanisms can be used to quickly detect
failure of tunnel(s)."

I think we'd probably need to have some text somewhere explaining how to
handle tunnel 
failures, and give some examples of what constitutes a failure.

John

_______________________________________________
Monami6 mailing list
[email-masked]
https://www1.ietf.org/mailman/listinfo/monami6

---

From: Henrik Levkowetz <[email-masked]>
Date: Wed, 14 Sep 2005 00:01:57 +0200

On 2005-09-13 08:44 [email-masked] said the following:
[...]

> "The WG does not plan on creating a tunnel selection mechanism, but
> may document how to use existing mechaims based upon preferences or
> policies for this. In particular, the WG will consider that a tunnel
> is alive as long as packets can be exchanged with the corresponding
> peer. In addition, local information , such as an interface went
> down, or other failure detection mechanisms can be used to quickly
> detect failure of tunnel(s)."

This would work for me, too.

s/mechaims/mechanisms/
s/interface went down/interface up\/down events/

	Henrik