Subject: Re: [MOBILE-IP] R-P agent should listen on port 434?

From: Patrice Calhoun <[email-masked]>
Date: Mon, 7 Feb 2000 09:31:19 -0800

The fact that they both listen on the same port IMPLIES that the
current I-D requires that they be one process.

PatC
>
>The draft in no way specifies that the R-P and Foreign Agent
>functionality is implemented in the same process.  I was pointing out
>that, although they both use port 434, they are on logically distinct
>IP interfaces and so can be implemented by the same or different
>processes as needed.
>
>-Pete
>
>Patrice Calhoun <[email-masked]> (PC) writes:
>
>PC> True, but the issue is that the spec, as-is, requires that a Foreign Agent
>PC> also support the R-P interface. Although the packets are similar, the
>PC> functionality provided is vastly different, begging the question as to
>PC> whether requiring that a single process provide both functionality is the
>PC> right design choice.
>
>PC> PatC
>>> The R-P agent needs to listen directly to port 434 on the internal
>>> (towards the radio access network) interface of the FA.  After an R-P
>>> tunnel is established, agent advertisements and registrations for
>>> Mobile IP are carried through the tunnel.  So the Mobile IP agent
>>> needs to advertise itself and take registrations via these tunneled
>>> endpoints, each of which could be considered to be a separate, logical
>>> interface.  So there should be no confusion between the R-P agent and
>>> the Mobile IP agent, as long as you can plumb these interfaces
>>> correctly.  Doing this in your particular implementation environment
>>> is left as an exercise for the reader. :)
>>>
>>> -Pete
>>>
>>> Ashish Mehta <[email-masked]> (AM) writes:
>>>
>AM> draft-ietf-mobileip-3gwireless-ext-02.txt alludes to R-P registration
>AM> messages being sent to UDP port 434. Does this imply that the mobile
>AM> IP agent (processing the MobileIP registrations) and the R-P agent
>AM> (processing the R-P registrations) are one and the same daemon/process?
>AM> It certianly appears so, since UDP would not be able to distinguish
>AM> between two unicast listeners on the same port.
>>>
>AM> Would'nt this be a problem for vendors who want to productize only
>AM> a mobile IP solution and use  a third party  solution for the R-P
>AM> agent?
>>>
>AM> Pardon me if this has already been discussed on the mailing list, but
>AM> I am curious if this has been given any thought.
>>>
>AM> ashish
>
>
>

---

From: Pete McCann <[email-masked]>
Date: Mon, 7 Feb 2000 13:16:12 -0600

I disagree.  They are on the same port but different interfaces.  This
can be done with distinct processes.  UDP sockets are multiplexed
based on both the port number and the IP address of the interface on
which they arrive.  The "virtual" interfaces created by the R-P tunnel
endpoints should be considered as logically distinct from the
underlying device on which the tunnel is carried.

-Pete

PC> The fact that they both listen on the same port IMPLIES that the
PC> current I-D requires that they be one process.