Subject: Addressing and MobIP IWF...

From: Per Johansson <[email-masked]>
Date: Wed, 18 Nov 1998 23:19:41 +0100

Hi All,

I have a couple of questions and concerns that to some extent relate to
the  applicability statement sent out by Scott. Some of these issues may

have been discussed earlier on the list but in that case I've forgotten
or missed them.

1) Manet and Fixed IP network interworking:
The first question relates to interworking between ad-hoc IP networks
(manets) and "fixed" IP networks. The latter may however use Mobile IP
(or use IPv6 mobility).

Is there any work available describing HOW manet routing protocols
interoperate with say Mobile IP? Should it be something described
explicitly in the applicability statement or is it captured by the
listed
questions. (It is mentioned in the manet issues document
(draft-ietf-manet-issues-02.txt))

2) Addressing and Identification:
How is an IP address allocated in an ad-hoc network?  This has been
discussed, I know, but I can't remember any detailed proposal on how to
do it.

There is a draft on IPv4 automatic address allocation when no DHCP
server is present
(draft-ietf-dhcp-ipv4-autoconfig-01.txt) but it concerns link local
addresses only, which is not the general case for a manet I suppose (?).

Has IPv6 in general better means to handle this (e.g. neighbour
discovery)?

In the issues document the Router ID is mentioned as a way to identify
manet "nodes" and enables routing between manet nodes with multiple
interfaces (IP-addresses). Is the RID a globally unique identifier and
if not how is it obtained?

Will the use of a RID affect the routing from a source within a fixed
network to a host in a manet (must RIDs be used in the routing tables in
the fixed network IP routers?)
When the dest. IP address of a host located in a manet is used by a
source in the fixed network isn't the "infrastructure technology" (the
interface) selected already at that point? If so, the first "manet
router" encountered must look up what RID this IP address is associated
with and use the RID to route through the manet to be able to use the
"best" link layers on that path (?).

3) Thin client considerations - (addition to applicability statement ?)
  One of the cases where manet routing could be applied is in networks
consisting of power and processing constrained clients (thin clients).
Would it be beneficial to state explicitly how a routing protocol is
intended particularly for such devices (maybe fits into "Networking
Context")?

Additional characteristics/requirements stated for thin clients could be

* Memory requirements (e.g.  code size + buffering)
* Computing requirements (estimated cpu-cycles?)
* How sleep mode is supported (it's mentioned I think)

I hope I stired up some discussion here (been a bit quiet on the list
lately :)

Thanks for listening!

/Per

Per Johansson, tekn. lic.
Dept. of Communication Systems
Lund Institute of Technology
Lund, Sweden

---

From: "M. Scott Corson" <[email-masked]>
Date: Thu, 19 Nov 1998 12:33:01 -0500 (EST)

> (draft-ietf-manet-issues-02.txt))

None of which I'm aware.  The appl. statement does not touch on this topic
other than asking whether the protocol supports the IP addressing architecture.

> discussed, I know, but I can't remember any detailed proposal on how to

None have been put forth.

> if not how is it obtained?

RID assignment is as unspecified as IP address allocation assignment.

> network to a host in a manet 

Only indirectly.

> (must RIDs be used in the routing tables in the fixed network IP routers?)

No.  The RID is intended to be known only to the network layer within
a MANET domain.  It is not visible outside the network layer, or outside
the MANET domain.

> interface) selected already at that point? 

No.  Any combination of technologies may be used to route to the router
with which the host is affliated.

> If so, the first "manet

Yes.  Ideally, the best combination of link layers should be used 
to get to the router with the affliated host.

> * How sleep mode is supported (it's mentioned I think)

Yes it would...I'll make a note of it.  The notion is somewhat addressed
in the existing appl statement (buried in questions such as...
"Does the protocol require the use of periodic messaging?")
but it is not explicitly asked.

Thanks,

-Scott

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M. Scott Corson                                 Institute for Systems Research
[email-masked]                              A.V. Williams Bldg. (115)
Phone: 301-405-6630 (Rm. 2205 AVW)              University of Maryland     
Fax:   301-314-8586                             College Park, MD  20742

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