Subject: [p2p-sip] Revised Draft Charter for P2PSIP

From: RADHIKA.R.ROY at saic.com (Roy, Radhika R.)
Date: Fri, 22 Sep 2006 16:06:07 -0400

Philip:
 
It is OK to look into those solutions using ICE for p2p-SIP.
 
A 2-year time period for development NAT-crossing standard for p2p-SIP will
be OK.
 
However, let us spend our most energy to develop the best p2p-SIP protocol
which is the future direction of the Internet.
 
Best regards,
Radhika
 
PS:
 
BTW: Even it is OK to cross NATs by p2p-SIP, will you also be looking for
the support of QOS so that NATs are NOT forcing more intelligent entities
around NATs not to mention NAT-crossing clients, servers, security patches,
QOS brokering, and many others so that cannons are used to kill a mosquito? 
 
If not, why not? If yes, would you and others provide suggestions to NSIS WG
as they are almost lost to do anything good that works well?
 
NATs will have their natural death as firewalls are much more superior to do
all those jobs of NATs without causing problems for SIP signaling and media
and other applications, but p2p-SIP is NOT.

  _____  

From: Philip Matthews [mailto:philip_matthews at magma.ca]
Sent: Fri 9/22/2006 1:24 PM
To: Henry Sinnreich
Cc: Michael Slavitch; Roy, Radhika R.; P2P-SIP
Subject: Re: [p2p-sip] Revised Draft Charter for P2PSIP

Henry:

Eric Cooper and I have spent quite a bit of time recently working on ICE to
make sure it is suitable for P2PSIP systems. 

Back in April, when we first looked at ICE, it worked well when one peer was
behind a NAT and the other had a public IP address, but was somewhat
inefficient due to duplicated checks when both endpoints were behind
(separate) NATs. We published a draft just before the Montreal meeting that
proposed changes to the state machine to eliminate that problem
(draft-matthews-mmusic-ice-eliminating-duplicates-00), and have since
collaborated with Jonathan on this issue so that the current version of ICE
(ICE-10) handles this case much better.

At present, I don't believe that any changes are required to ICE-UDP itself
to make it more suitable for P2PSIP systems. (I haven't looked at ICE-TCP in
detail yet). The only questions now are around how one uses ICE in a P2PSIP
network, and here at Avaya we are currently investigating this issue,
building on our proposals in draft-matthews-p2psip-nats-and-overlays-00.

- Philip

On 22-Sep-06, at 10:13 , Henry Sinnreich wrote:

This may not fit into the charter discussion, but joining Michael Slavitch,
I would be interested if any or what modifications ICE would be required for
P2P systems, where most peers reside behind a NAT.

Any opinions? Jonathan?

Thanks, Henry

  _____  

From: p2p-sip-bounces at cs.columbia.edu
[mailto:p2p-sip-bounces at cs.columbia.edu
<mailto:p2p-sip-bounces at cs.columbia.edu> ] On Behalf Of Michael Slavitch
Sent: Friday, September 22, 2006 9:45 AM
To: Roy, Radhika R.
Cc: p2p-sip at cs.columbia.edu <mailto:p2p-sip at cs.columbia.edu> ; David A.
Bryan
Subject: Re: [p2p-sip] Revised Draft Charter for P2PSIP

It is certainly not a nonsense problem outside of some rare circles as
nearly all consumer and business networks fall behind NATs. Without NAT
crossing P2PSIP is useless. I agree that in a deterministic system a perfect
solution is required. 

That is why deterministic systems are always so brittle. The world is a
messy fractal place.

By definition P2PSIP will not be deterministic so a perfect solution is not
only unnecessary, it is not desirable if the cost of complexity exceeds the
apparent benefit.

The solutions that exist are statistical and fractal, not perfect and
deterministic. Skype is living proof of a broadly used implementation that
shows that the problem is solved in a matter that meets the requirements for
P2P systems.  Since all P2P systems share a common fractal nature a fractal
solution is perfectly suited to the domain.  

For all the criticism of ICE, and I've done my fair share, it is getting
simple enough to implement from the draft to be expressed in BNF notation.
It is now fairly easy to build ICE into a finite state machine, as ICE now
describes a completion mechanism where the protocol is complete. That
encourages  interoperability from the start.  

Any inadequacies that remain result from the fact that client-server SIP is
the only official user of the protocol.  These are minor issues that can
only be addressed by MMUSIC once we have a P2PSIP WG that can request
changes.  That is a diplomatic problem, not an engineering problem, if the
underlying protocol in ICE can meet base P2PSIP requirements.  That is why
WG chairs are chosen carefully. 

Regarding unsolved problems:  If the underlying system is fractal then a
statistical solution with a high probability of success meets the
requirements for the system. This is true for all fractal systems.   The
only issue is determining the probability of success of different solutions
and either choosing one that meets the circumstances at hand or modifying
another to make it an appropriate choice.  

I further argue that the fractal nature of ICE is far more suited to the
fractal P2P world than it is to the assumed-deterministic IMS/CS model. It
may be not ever be solved perfectly enough for IMS but for self-organizing
P2PSIP it won't have to be perfect as the nature of a self-organizing
systems is to work around their own shortcomings.   P2PSIP will be rugged
enough such that perfect solutions are not needed.  If the other working
groups are failing it may be because the systems they are building towards
may be broken and brittle and not rugged enough to tolerate statistical
solutions. Given the talent at hand that will certainly not be the case with
P2PSIP. 

Regards

M

On 9/21/06, Roy, Radhika R. <RADHIKA.R.ROY at saic.com
<mailto:RADHIKA.R.ROY at saic.com> > wrote: 

M:

The ONLY reason is this: It is an unsolvable problem.

All IETF WGs have been trying, and have been failing successully!!! 

The word UNFORTUNATE is there to discourage for spending too much time for
this technically nonsense problem. That is, p2p-SIP may not be even p2p-SIP
WG anymore at the end of the solution - all fear is this: It might make 
p2p-SIP NAT crossing solution as non-p2p-SIP NAT crossing protocol.

I hope I would be  be wrong! Who knows what is coming out of by SIP,
SIPPING, NSIS, IPSEC, DIAMETER, and others almost after 6-10 years!  Now, 
MMUSIC has turned their attention to ICE-xxxxxx versions.

Let us wait for ICE (versions # infinite) to see whether it could be used
for p2p-SP!!! How about this?

RRR

_____

From: Michael Slavitch [mailto: slavitch at gmail.com
<mailto:slavitch at gmail.com> ]
Sent: Thu 9/21/2006 2:32 PM
To: Roy, Radhika R.
Cc: David A. Bryan; p2p-sip at cs.columbia.edu <mailto:p2p-sip at cs.columbia.edu>

Subject: Re: [p2p-sip] Revised Draft Charter for P2PSIP 

The "NAT is evil" argument is a matter of faith and belief, a moral
statement that has no place in a protocol working group charter.
Engineering solutions emerge from the judicious study of discernible 
reality. NAT exists, therefore it must be dealt with. Period.
>From an engineering standpoint, it creates problems that need to be solved
with solutions that reflect the facts on the ground.

The P2PSIP Working Group must be part of the reality-based community, rather

than part of an ideological community, therefore the working group charter
must distinguish consensus external reality from ideologically created
reality if the working group is to be at all successful.  There is ample 
evidence that creating one's own reality despite evidence to the contrary
results in failure.

Given that, the word "unfortunate" has no place in an engineering document.
By definition it must be struck. 

Regards,

M

On 9/21/06, Roy, Radhika R. RADHIKA.R.ROY at saic.com
<mailto:RADHIKA.R.ROY at saic.com> 
<mailto:RADHIKA.R.ROY at saic.com <mailto:RADHIKA.R.ROY at saic.com> >  wrote: 

Mike and all:

I am commenting on NATs.

>From IETF point of view, the use of NATs as it is done these days is
"unfortunate."

Let us see what had been the history of NAT standardization in the IETF? 

The IETF charter had been to help the "scarcity" of IPv4 addresses (before
IPv6 even been proposed). It was hoped that, by the time IPv6 is
standardized, there is will be no more requirements of NATs to provide more 
address spaces.

Now, people have forgot the original usage of NATs. People are using NATs as
a part of "security" for hiding the configurations behind NATs. It is
completely an "illusion" to be happy to know that people are "secured" by 
using NATs. It is still going on in a mass scale throughout the world, and
no one knows when this will be stopped.

Should the purpose of the NAT standardization be "SECURITY" or "TOPOLOGY
HIDING in the name of security," IETF would NEVER standardized NATs for 
these purposes. The rest is history!!!

So, it is UNFORTUNATE so far the MIS-use of NATs is concerned because NATs
are not needed anymore due to shortage of IPv4 addresses or NATs cannot
provide security through hiding configurations. 

Therefore, the draft charter is CORRECT in this context to use the word
"UNFORTUNATE."

Best regards,
Radhika

_______________________________________________
p2p-sip mailing list
p2p-sip at cs.columbia.edu <mailto:p2p-sip at cs.columbia.edu> 
https://lists.cs.columbia.edu/cucslists/listinfo/p2p-sip
<https://lists.cs.columbia.edu/cucslists/listinfo/p2p-sip>

---

From: philip_matthews at magma.ca (Philip Matthews)
Date: Sat, 23 Sep 2006 12:36:08 -0400

> A 2-year time period for development NAT-crossing standard for p2p- 

I am hoping that it will not take us two years to agree on a standard.
[Of course, it has taken us almost a year and a half so far to get  
the WG formed,
so perhaps I am being foolishly optimistic]

> QOS brokering, and many others so that cannons are used to kill a  

We have not considered QOS issues in our work to date.
We are still considering basic connectivity issues.

- Philip