Subject: [MOBILE-IP] Doubts from <draft-elmalki-soliman-hmipv4v6-00.txt>

From: Karann Chew <[email-masked]>
Date: Tue, 1 Aug 2000 00:44:55 +0100

Dear All,

Just read this draft, and am have some doubts.

Section 3, paragraph 3:
"If the packets for the MN are tunnelled from the HA, then the GFA should
change the source and destination IP address of the encapsulating header to the "next" FA towards the MN."

Do the authors mean changing source address to GFA's address, whereas
destination address is changed to the address of the next FA towards the
MN?

Another question (which is not the main issue in this draft):

Section 2, Paragraph 1 and 2 read:
"a MN may be attached directly to any FA within the hierarchy and may
move between FAs from different levels in the hierarchy. The following
figure describes the Hierarchical MIPv4 network.
                          ________
                         |        |
                         |  GFA   |
                         |________|
                          /   |  \
                        ...  ...  ...
                          ____|___
                         |        |
                         |   FA3  |
                         |________|
                    ______/_     _\______
                   |        |   |        |
                   |   FA2  |   |   FA1  |
                   |________|   |________|
                    ____|___     ____|___
                   |        |   |        |
                   |AP/RAN 2|   |AP/RAN 1|
                   |________|   |________|
                        |        ____|___
                                |        |
                       CN       |   MN   |
                                |________|

      Figure 1: Multi-level Hierarchical MIPv4 domain.

In the above figure, Access Points (APs) or Radio Access Networks
(RANs) consisting of multiple access points, are used to provide a MN with
L2 access."

Am I right to say that: when one states that a MN may be attached to and
moved freely among FAs at different levels of the hierarchy (such
statement appears not only in this draft, but others such as HAWAII), it
is assumed that all of the FAs are connected to some kind of Access
Points or RAN?  So, the FA1, FA2, FA3 in figure above should be connected
to some radio access points/network?

If so, how's the network practically look like?  Any example?  What
about: Each FA is connecting to a WaveLan ??  How about the appliciable of
these  hierarchical architecture in a cellular network??

Perhaps I'm confused, or misunderstood some points.  Advice &
comments for enlightenment are much appreciated.

Cheers!
        Karann

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
             Karann Chew
   Mobile Communications Research Group
Centre for Communication Systems Research
          University of Surrey
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~