Subject: [multimob] PMIP Unicast Routing

From: "Thomas C. Schmidt" <[email-masked]>
Date: Thu, 09 Jan 2014 20:39:02 +0100

Hi Behcet,

On 09.01.2014 19:20, Behcet Sarikaya wrote:

> My question was not related to this document specifically.

As far as I'm aware of, this subject is not related to any WG item of 
Multimob ... that's why I put it in a new thread.

> So my conclusion from your reply is that there is no written document on
> so-called policy routing in PMIP. Certainly RFC 5213 does not mention it.
>

PMIP describes unicast routing, only, not multicast. Forwarding from the 
MN is described in Section 6.10.5.

There it says:

"   o  On receiving a packet from a mobile node connected to its access
       link, the mobile access gateway MUST ensure that there is an
       established binding for that mobile node with its local mobility
       anchor before forwarding the packet directly to the destination or
       before tunneling the packet to the mobile node's local mobility
       anchor.

       ...

     o  On receiving a packet from a mobile node connected to its access
       link, to a destination that is not directly connected, the packet
       MUST be forwarded to the local mobility anchor through the bi-
       directional tunnel established between itself and the mobile
       node's local mobility anchor.
"

Aside from a typo (not "to" but "by the local mobility anchor"), this 
describes a routing procedure, which is not regular IP routing 
(according to the destination address), but according to a 'policy' (the 
"established binding for that mobile node with its local mobility 
anchor"). Often, such forwarding decisions are referred to as 
'policy-based' routing - RFC 5213 does not name this procedure, but 
describes it only verbally.

When I used the term 'policy-based routing', I was referring to this 
quoted paragraphs on PMIP forwarding from the MN. The term is not 
important. What matters is that the forwarding decision is based on the 
source, not on the destination address.

However, if you are interested in the nitty gritty details of PMIP, you 
should probably discuss with the real PMIP experts. I've neither 
designed, nor implemented PMIP.

Best regards,

Thomas

-- 

Prof. Dr. Thomas C. Schmidt
° Hamburg University of Applied Sciences                   Berliner Tor 7 °
° Dept. Informatik, Internet Technologies Group    20099 Hamburg, Germany °
° http://www.haw-hamburg.de/inet                   Fon: +49-40-42875-8452 °
° http://www.informatik.haw-hamburg.de/~schmidt    Fax: +49-40-42875-8409 °