Subject: Re: [mif] draft-blanchet

From: Jari Arkko <[email-masked]>
Date: Mon, 09 Feb 2009 11:19:25 +0200

Gerardo,

Sorry for the late response:

>> 4) Routing: If a host is attached to a number of different interfaces,
>> where does a particular IP packet go?
>>
>> 5) Address selection: If a host is attached to a number of different
>> interfaces, which addresses should be used for a particular application
>> flow?
>>
>> 6) Tunnel multihoming: If a host is attached to a number of different
>> interfaces and runs some kind of a tunneling or mobility back to a home
>> agent, which interface and addresses should be used for a particular
>> packet? Already covered in existing MEXT WG work items.
>>
>>     
> How is it 4 different from 6? My understanding is 6 already covers how routing is performed as you indicated. Or is the intention of 4 to provide hints to e.g. MIPv6 extensions so that a certain interface/CoA is registered for a given IP flow?
>   

It is part of the same functionality, but what sets them apart in my 
mind is the following. In the mobility protocols there is someone else 
(such as the home agent) on the other side who is acting the receiver of 
the information, essentially hiding the use of the different addresses 
and interfaces from the eventual recipient of the packets.

You can also view the tunneling protocol support for multiple tunnel 
endpoint addresses as a specific solution to point problem. If we had 
TCP/IP stacks that were generally capable of using any interface and 
address, and where any application would be capable of withstanding an 
address change, we could run our tunneling protocols on top of that, and 
they would not need special support. But we don't have such stacks...

Jari