Re: Flow label - the problem

[Iljitsch van Beijnum <iljitsch@muada.com>]

On 21-apr-2005, at 20:53, marcelo bagnulo braun wrote:

> > In BGP and other routing protocols systems usually have a router  
> > id so another system can detect that it's talking to the same  
> > remote system over different links. We can do the same thing here.  
> > This value doesn't have to have any meaning to the remote system,  
> > the only requirement is that it's unique. A good choice for this  
> > would be one of the IP addresses of a host or maybe the interface  
> > identifier if that contains enough uniqueness.

> but in this case, the real context tag used for demux would be the  
> id, not the flow id value. so you would have to include it in every  
> packet, back to where we start, i am afraid.. or i am missing  
> something?

No, this id would be looked at when selecting the flow label for a  
new session. I.e.: when selecting a new flow label, the host would  
see if the flow label overlaps with one currently used, and then:

- overlaps with known non-shim session: allow if dest addr is different
- overlaps with known shim session: allow if shim id is different
- overlaps with session of unknown type: don't allow

There are probably other places wher ethe shim id would be useful too.

Iljitsch