Subject: Re: [Mip4] New version, draft-ietf-mip4-nemo-haaro-01

From: Alexandru Petrescu <[email-masked]>
Date: Wed, 28 Jul 2010 23:27:38 +0200

Le 12/07/2010 11:19, Antti Mäkelä a écrit :
> Hi,
>
> I just uploaded new version of Haaro. Changes include NAT handling
> (multi-interface situations), adjustments to keepalive, more details
> on concurrent moving handling, some changes in protocol fields to
> reduce state information and allow for more conditions. [...]

http://tools.ietf.org/html/draft-ietf-mip4-nemo-haaro-01

Hi Antti,

This review shows only some comments I have now.  Later I could send more.

The draft describes a Route Optimization method for Mobile IPv4 and
NEMOv4, between Mobile Routers and their respective moving networks.
MRs inform their HA about capability to do RO and then the other MR's
(CRs, correspondent) ask for the CoA of a MR from HA, thus HA
subsequently gets out of the path MR-CR.

Draft is 45 pages long, includes packet formats and message exchange
diagrams.

> Even though general route optimization may not be of interest in the
>  scope of IPv4, there are still specific applications for Route
> Optimization in Mobile IPv4.

When reading this I expect to read about which are those specific apps
for RO in MIPv4... just a few names like relocating a site, a paragraph
appearing later in the draft anyways, but my reading needs it here..
reading style.

> This draft proposes method to optimize routes between networks behind
> mobile routers, as defined by NEMO [RFC5177].

This reads as if RFC5177 were a method to optimize... it's not, we
know, it's just about the mobile routers part... maybe I read it
wrong.

> such as MAE-WEST

Is there a similar point in Europe somewhere, like Amsterdam for example.

>    Host Network Prefix
>
>         Network Prefix with the mask of /32. e.g. 192.0.2.254/32,
>         consisting of a single host.

Is 192.0.2.254 a form of documentation prefix or so? (like the
2001:db8:: in IPv6) I am just asking, worried if it were a publicly
routable address.  I know, I use these things in ly own drafts
arbitrarily but it's good to keep in mind what should be better there.

>    Route Optimization Cache
>
>         Data structure maintained by Mobile Routers on possible
>         destinations for Route Optimization.  Contains information (Home
>         Addresses) on potential Correspondent Routers and their
>         associated Mobile Networks.

I am used with ARP Cache, MIP6 Binding Cache, MIP6 Binding Update
List... but for MIP4 I am used to Registration Table not Cache, or ...

but of course it's up to you, I can grasp it as such Route
Optimization Cache.  .

It's just that there may be a need for a name for this conceptual data
structure which is more than just RO, and in which some RO fields may
be needed.

For example MR RFC5177 has already a "Prefix Table" used for ensuring
security of mobile network prefixes.  Were we to combine the Prefix
Table and the Route Optimization Cache into a single conceptual
structure, maybe it would be better.

Or similar.

>    Return Routability, RR
>
>         Procedure to bind a Mobile Router's Home Address to a Care-of
>         address on a Correspondent Router with a degree of trust.

"RR" abbreviation is heavily overloaded at IETF meaning also RegReq,
Resssource Record of DNS and more.  Up to the local context, but it's
good to know.

>    The schema requires a Mobile Router to be able to receive messages
>    from Home Agent and other Mobile Routers unsolicited - that is,
>    without first initiating a request.  This behavior is similar to the
>    registration revocation procedure [RFC3543].  Many of the mechanisms
>    are same - including the fact that advertising route optimization
>    support upon registration implies capability to receive registration
>    requests and return routability messages from other Mobile Routers.

This reads as a modification to the RFC3344 and RFC5177 MR which
assume that only HA can receive Registration Request.  (rfc3344
section 3.8.2 "Receiving RegReqs" - there is no such section for MN,
only for HA).

These are just non substantive, editorial stuff... more substantive to
follow after the meeting.

Generally speaking I like the idea in the draft, makes sense to me.

Alex

---

From: Antti Mäkelä <[email-masked]>
Date: Thu, 29 Jul 2010 10:00:07 +0300 (EEST)

> 2001:db8:: in IPv6) I am just asking, worried if it were a publicly

   Yeah. See RFC 5735 about TEST-NET-1.

--
- Antti Mäkelä | Researcher -
- Department of communications and networking -
- Aalto University -