RE: What is the purpose of the discussion? Answer

[James Kempf <James.Kempf@Sun.COM>]

Chris,

Not sure I exactly follow your laundry metaphor, but I think you
bring up some good points. Specifcally:

>As a person who's been in the wireless data industry for nearly 20 years, I see 
genuine system-specific requirements in many of these categories, but I don't 
see any of them requiring a wireless-specific change in the overall 
architectural philosophy of the internet. My guess is that many of these 
requirements can be satisfied 90% by solving the related problem for the 
internet at large; this is the problem set I think the IETF should address.

I agree that many of the issues brought up in the draft are not specific
to wireless. The reason that they are coming up in this context is
that some wireless operators and SDOs have been more willing to push
the envelope in terms of deploying all IP solutions. Wire-line operators,
while slowly moving to IP for long haul, seem pretty much satisfied with the
current technology for edge network use, whether that be due to
lack of competition, lack of any compelling need for new technology, etc.
Wire-line ISPs, on the other hand, haven't really stressed many of the
issues in their requirements, since they have been up until now happy
with simpler accounting, etc. The result has been that the requirements
that are not strictly confined to wireless have been trickling in from
interactions between wireless ISPs/mobile operators and the IETF. The
draft, this mailing list, and the BOF if it happens are an attempt
to bring some focus to the discussion.

>
>The set of truly wireless-specific technical issues is rather small. Here's the 
basis set:
>
>1) Micro-mobility - Some wireless nodes move around; some change their network 
point of attachment multiple times within a session; some use time-variant / 
intermittently viable link layers for which packet loss does not imply 
congestion; some use asymmetric link layers; some use relatively slow (2 or more 
orders of magnitude below wired internet speeds) link layers (PILC wg, Mobile IP 
wg, IPNG wg stuff)
>
>2) Economic assumptions - Some wireless nodes make use of scarce, expensive 
communications bandwidth (e.g. $0.10 charged to the user for every kilobyte of 
data transfer; $0.30 charged to the user for every minute of a session); some 
have very limited compute capability, storage capability, display capability, 
data entry capability, etc (factors encouraging specific types of protocol and 
application optimizations including application layer gateways like WAP)

Agree.

>
>3) Regulatory environment - Some wireless nodes operate in a different 
regulatory environment than the U.S. conception of the wired internet. As 
wireless devices become less telephone-like and more internet-host-like, the 
response from global regulators ranges from reactionary to insightful. 
Regardless of the specific regulatory reaction, typically vendors and service 
providers of wireless devices operate under regulatory constraints that imply 
(sometimes ludicrous) technical "requirements" for wireless nodes.

Well, I think this is something that the IETF, as an engineering organization,
has little control over. I suppose the vote last year to not put
Trojan horses into protocols for wiretapping is an exception, but in
reality there is little that we can do in this area. It is up to ICANN
and others involved in Internet politics. Naturally, we can have an
opinion.

I also think you've missed a couple points. For example:

4) QoS. The current IntServ protocol, RSVP, is designed for nonmobile
hosts. The design accommodates changes due to routing updates but
not to mobility, in terms of performance. To my understanding, the
use of RSVP is now somewhat deprecated for a variety of reasons
not related to its poor fit with mobility, but the suggested alternative,
Diffserv, is also not an appropriate solution for access networks, 
in particular, radio access networks. Diffserv encourages overprovisioning
and because the wireless access network is expensive to deploy, most
wireless ISPs would like to avoid overprovisioning on the edge. Mobile
operators would also like to see end to end QoS, with which Diffserv has
a problem.

5) Location based services. IETF had a working group in this area, it
is now dormant. Seems like a standardized way of obtaining geolocation
information independent of the radio protocol would be a positive
stimulus to location based services.

>
>We might go a long way toward addressing the genuine concerns of the wireless 
industry, if the IETF and MWIF were to focus on defining a "memo of 
understanding" on which parts of the problem are appropriate IETF issues and 
which belong in MWIF. The objective of the MoU would not be to carve up turf, 
but rather, to set expectations, avoid misunderstandings, and speed progress 
toward solutions.

MWIF served as the venue for getting these requirements on paper, but
beyond that, I don't think  MWIF is or should be involved. It is
not an SDO, and it is not currently doing any protocol work that
would be of interest to the IETF. If in the future MWIF does do
some work that is of interest to IETF, then the IETF can look at
how to bring that work in, as was done, for example, with the
Multivendor Switching Forum. Better for the wireless operators
to come directly to IETF themselves.


		jak