Re: flow label demultiplexing

[marcelo bagnulo braun <marcelo@it.uc3m.es>]

El 19/04/2005, a las 13:17, Iljitsch van Beijnum escribió:

> On 19-apr-05, at 11:46, marcelo bagnulo braun wrote:
>
> > > There are two obvious options:
>
> > > 1. The flow label is relevant regardless of the addresses: this 
> > > can't work because of the possibility of clashes with flow labels in 
> > > unrelated packets
> > > 2. The flow label is only relevant with certain source/dest address 
> > > combinations: but what's the additional benefit of the flow label 
> > > here, we can demultiplex on the addresses
>
> > Well, there could packets with the same src and dst address, that 
> > belong to different communications with different ULIDs, right? the 
> > flow label is to determine the proper demux context.
>
> Under what circumstances would having different associations between 
> the same source and destination locator sets be necessary and/or 
> useful?
Well, i think they may occur pretty naturally, and that we probably 
need to do something in order to avoid it from happening. Correct me if 
i wrong in the next scenario:

Node A has IPA1 and IPA2
Node B has IPB

Two communications are initiated between the nodes. Because no address 
is preselected, one of the communications is using IPA1 and IPB as 
ULIDs and the other one is using IPA2 and IPB as ULIDs. Now an outage 
occurs affecting IPA1 and the communication involving IPA1 and IPB is 
moved to the alternative locator i.e. IPA2.

At this point, packets corresponding to any of the communications 
contain the same addresses, IPA2 and IPB, and they need to be 
demultiplexed.

I guess we could came up with more complex scenarios where the locators 
used are not being used as ULIDs in any of the established 
communications.

Makes sense?

regards, marcelo