Subject: Bluetooth capabilities over 802.11/HyperLan?

From: Phil Neumiller <[email-masked]>
Date: Tue, 30 May 2000 09:08:44 -0500

I have a question.  In looking over the list of work in progress in manet, I see
that some really basic stuff is missing.  For one, it seems quite plausible to me
to facilitate ad hoc networking at the IP layer (using IPv6 neighbor discovery),
over any radio link, i.e. Bluetooth or 802.11 or HyperLan for that matter.  

My gut feeling is that the designers of Bluetooth went a bit too far up the stack
when they added "ad hoc" networking and other baggage to the Bluetooth recommendation.
It seems to me that what we want to do is have manet-like capabilities specified
at the IP layer so that we can change out radios as needed.  With this in mind,
can somebody write a draft that puts these really basic Bluetooth capabilities
like cable replacement, ad hoc networking, over manet so that we eventually have
an RFC standard for the really basic stuff?

Phil

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From: "Charles E. Perkins" <[email-masked]>
Date: Tue, 30 May 2000 10:33:25 -0700

Hello Phil,

> over any radio link, i.e. Bluetooth or 802.11 or HyperLan for that matter.

I agree that it is plausible to facilitate ad hoc networking at the
IP layer, but I don't know why you think we missed this possibility.
Or do you mean that it should be done _only_ by IPv6 neighbor discovery?
Then we have to agree on what constitutes a link.  Is it a single
hop over the wireless medium?

If you mean that we are missing IPv6 specifications in manet, then
I don't understand how that relates to the rest of your message...

> an RFC standard for the really basic stuff?

But what is the really basic stuff?!  As I understand things, current
manet drafts do have the feature you identify, allowing radios to be
changed out as needed.

Perhaps you could volunteer to write a draft to start
the discussion.

Regards,
Charlie P.

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From: "Samir R. Das" <[email-masked]>
Date: Tue, 30 May 2000 14:09:45 -0400

Phil:

I don't think I understand your question/comment well.
The manet drafts do indeed allow routing at the IP layer
and this allows for multiple types of radio in the. In fact the manet
protocols are radio independent for the most part, though
some may utilize certain radio functionality such as link-layer
acks to take some routing layer decisions. These are 
typically clearly specified in the Internet drafts.

Samir

> -----Original Message-----
> From: [email-masked]
> [mailto:[email-masked]]On Behalf Of Phil Neumiller
> Sent: Tuesday, May 30, 2000 10:09 AM
> To: [email-masked]
> Subject: Bluetooth capabilities over 802.11/HyperLan?
> 
> 
>

---

From: Phil Neumiller <[email-masked]>
Date: Tue, 30 May 2000 13:06:06 -0500

Charles,

I think writing a draft may be good.  However, I may not be able to do this
anytime soon.  It seems like the manet work in progress (drafts) and RFCs 
all address some particular aspect of ad hoc ROUTING: (AODV, TORA, DSRP,
ODMRP, OLSRP, INSIGNIA, RDMAR, STAR) yet am I to assume that all these
are the "baseline manet architecture"?  Is manet just routing?  What can
I build today that works but is not necessarily optimal and where is THIS
specified?  What seems to be missing is the manet equivalent of the
Mobile-IP RFC 2002 (which I am sure you are intimately familiar with :-).
Maybe its too soon for this sort of thing?

> IP layer, but I don't know why you think we missed this possibility.

OK, it may not be missed, but I know that Microsoft is going ahead and
binding Winsock to RFCOMM (a Bluetooth serial port emulator), and I think
this is a bad idea. There are probably other product plans being based
on Bluetooth's ad hoc capabilities rather than IP's.  This is my concern.
What I would like to see (if somebody has more bandwidth than me), is
a simple specification of what it means to be ad hoc in the IP sense.
For instance does this mean that I must use NDP when IPv6?  Does this mean
I use ICMP messages of some sort when I am IPv4?  

> Or do you mean that it should be done _only_ by IPv6 neighbor discovery?

No, something has to be done for v4 too.

> hop over the wireless medium?

Usually, otherwise its a route a guess.  If you use link local addresses
or network local addresses it pretty much has to be a link.

> I don't understand how that relates to the rest of your message...

Yes, the rest of my message was to show some concern that if manet does
not have an assumed baseline architecture and protocol for v4 and v6
other less desirable ad hoc networking schemes may crop up in commercial
products.

Thanks,

Phil

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From: "John Wells" <[email-masked]>
Date: Tue, 30 May 2000 14:32:26 -0400

Maybe I'm missing something, but it seems to me that MANET routing protocols
should operate between the data link layer and network layer.  That means
that IPv6 wouldn't care if it was running on top of a MANET or a wired
network.

John

-----Message d'origine-----
De : [email-masked]
[mailto:[email-masked]]De la part de Charles E. Perkins
Envoye : Tuesday, May 30, 2000 1:33 PM
A : Phil Neumiller
Cc : [email-masked]
Objet : Re: Bluetooth capabilities over 802.11/HyperLan?

[...]

[...]

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From: "M. Scott Corson" <[email-masked]>
Date: Tue, 30 May 2000 14:44:20 -0400 (EDT)

> a simple specification of what it means to be ad hoc in the IP sense.

Phil,

Joe and I have tried to be a little forward-looking and architectural in
our thinking about what it means to be ad hoc in the IP sense, but have 
encountered resistance within the working group when we tried to perhaps
overspecify things too early in the WG's life.

Some of those architectural thoughts still exist in the perf. issues RFC

http://www.ietf.org/rfc/rfc2501.txt

Also, a lot of our MC2R articles contain more thoughts along these lines
and they hang off Joe's page.

http://tonnant.itd.nrl.navy.mil/macker/pubs.html

None of what we discuss deals with v4 vs. v6 issues, zeroconf-compatibility,
etc.  Mostly just architectural suggestions and rationale for ad hoc design.

I (as a WG member) would like to see drafts regarding ad hoc routing and
service discovery, zeroconf, address autoconfiguration, etc...documents that
begin to suggest a framework and environment in which IP manet technology
in general and a routing algorithm in particular can operate.

-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

*******************************************************************************

---

From: "Charles E. Perkins" <[email-masked]>
Date: Wed, 31 May 2000 08:02:08 -0700

Hello Phil,

>            It seems like the manet work in progress (drafts) and RFCs

I think that you are looking for a "system", and IETF working
groups tend to make protocols instead of systems.  Indeed, I also
think that many people wish to make Mobile IP into a self-contained
system, even though it was always designed as a single protocol.
I think other protocols (e.g., SIP) may fall prey to the creeping
feature creature in an attempt to become systems instead of protocols.

I wouldn't say that manet has to be exclusively concerned with
"just routing", and I support Scott's call for drafts dealing with
autoconfiguration and service discovery.  Indeed, we have made
AODV drafts that include text concerned with just those issues.
It's not too soon, especially if you have some good ideas about
these things.

> I use ICMP messages of some sort when I am IPv4?

IP is good for transmitting packets over a link, and for
hooking together networks.  It's not good for managing
link-specific details.  What it means to be ad hoc in the
IP sense is to create a network by putting together links
as needed at the time (in an ad hoc way).

I think that NDP is expected to be used when all nodes on
the same link share an IP address routing prefix.  This is
not necessarily true in an ad hoc network.  I also believe
that the IPv6 case for network prefixes that can be shared
by nodes that are not "on-link" is pooly specified at present,
and may not work well in the ad hoc environment.

If Microsoft jumps the gun and creates APIs based on programming
models that are currently incomplete, the fault cannot necessarily
be laid at the doorstep of the IETF.  As best I can remember, no
one from Microsoft (and precious few from Bluetooth) has ever
contributed to a manet working group meeting.  I have quite
often suggested that AODV would be a good choice for gluing
together scatternets, but I am unable to really champion this
at Microsoft or at the various Bluetooth venues, so it may go
nowhere.  Perhaps what is needed is some Proposed standard
protocols from the manet working group.

Regards,
Charlie P.

---

From: "Fred L. Templin" <[email-masked]>
Date: Wed, 31 May 2000 10:04:52 -0700

> that IPv6 wouldn't care if it was running on top of a MANET or a wired

I think this digs at the heart of the matter. I really believe that
what goes on with MANET-style routing can thought of as a lower-level
network layer function that is almost (but not quite!) akin to a
datalink layer bridging function with dynamic topology discovey
capabilities. Although the OSI reference model is largely deprecated
with respect to Internetworking discussions, one might think of MANET
routing as a layer 3a (subnet access layer) function and Internet routing
as a layer 3c (internet layer) function.

We have implemented a MANET-style routing protocol called Topology Broadcast
with Reverse Path Forwarding (TBRPF) by using IP host routes (we support
both IPv4 and IPv6) that enable an intra-domain multihop relaying capability
within the domain of an individual mobile ad-hoc network. In our implementation,
these host routes have either IEEE 802 link-layer address resolutions for single
hop neighbors or the IPv4/v6 address of the next relay hop in the path to
reach multi-hop destinations. We additionally support inter-domain routing by
exchanging aggregated IPv4/v6 network prefix routes via traditional Internet
routing protocols (such as RIP, OSPF, etc) to enable routing between multiple
mobile ad-hoc networks and/or the fixed Internet infrastructure. In this way,
our host routes are managed by TBRPF and implement the layer 3a function while
the aggregated prefix routes are managed by traditional Internet routing
protocols (such as RIP, OSPF, etc) and implement the layer 3c function. In
general, we believe the IP-based approach provides greater flexibility than
delving into the datalink layer, but I'd like to provide the following
discussion as to one reason why I think this is so.

My intuition is that a datalink layer approach may be acceptable for
MANETs in which the mobile nodes by-and-large "stick together", but the
IP-based approach has distinct advantages for MANETs in which the mobile
nodes roam about independently of one another. An example of the former
might be a bluetooth-based PAN in which a user has a collection of personal
devices which either rarely leave his possession or are rarely shared
with other users. In this case, if the MANET function is perfomed at
the datalink layer, each device can be assigned an IP address with a
common prefix and each device need only maintain an aggregated route
for the common prefix - not individual host routes. The user could end
up transmitting a message that gets relayed from his laptop, through his
cell phone, through his palm pilot and to his printer without the IP layer
ever being aware of the multi-hop situation. In essence, the PAN looks just
like a wired Ethernet from the standpoint of IP since the bluetooth datalink
layer performs the MANET routing function transparently.

But, in cases in which the mobile nodes in MANETs roam about independently
of one another, nodes may frequently change their current MANETs of
affiliation. In this case (which I believe will be the rule rather
than the exception) it is no longer reasonable to expect that the
nodes in the MANET will all have a common IP network prefix (unless
some form of dynamic address assignment is used). Instead, the MANETs
will over time become heterogeneous conglomerations of nodes with
different IP network prefixes. Therefore, it will not be possible to
assign aggregated prefixes for intra-MANET routing. Instead, host routes
which are dynamically created/modified/deleted in response to topology
changes will be necessary to support intra-MANET multi-hop relaying and
something like MobileIPv6 will be necessary to keep track of roaming
nodes that have left their "home" MANETs.

Fred Templin
[email-masked]