Subject: [p2p-sip] WG or not (was: dhts)

From: matthewsp at avaya.com (Matthews, Philip (Philip))
Date: Wed Nov 2 09:52:35 2005

Radhika:
 
I should just point out that everything we are talking about is
preliminary.
There is, as present, no working group nor is there any official
decision to form one.
We are still trying to figure out what the work items of a possible WG
might look like.
After that, we must hold an official BOF and convince the IESG to form a
WG.
None of this is guaranteed to happen.
 
So when you say "Philip has answered my main question that we will
standardize a p2p protocol",
what is really true is "Philip is throwing out a suggestion that this
(unofficial) group should discuss
the idea of standardizing a simple P2P protocol".
 
- Philip

  _____  

	From: [email-masked] [mailto:[email-masked]] 
	Sent: November 1, 2005 16:26
	To: Matthews, Philip (Philip); David A. Bryan; Eunsoo Shim
	Cc: [email-masked]
	Subject: RE: [p2p-sip] dhts

	Hi, David and Philip:

	It is not that I am disagreeing with you. In fact, Philip has
answered my main question that we will standardize a p2p protocol. Like
others, I also definitely agree with Philip as he has proposed, but in
reverse order:

	1.      Standardize a simple protocol Z as the default P2P
protocol 
	2.      Standardize a negotiation mechanism for the P2P protocol
being used in a group 
	3.      Standardize a framework for hierarchical P2P networks 

	Now, if we start with item 1, we have to see couple of basic
items (something) as follows:

	a.      Discovery (as a part of the p2p protocol) 
	b.      Lookup (as a part of the p2p protocol) 
	c.      Content Transfer between peers directly (will be
triggered or invoked as a result of p2p [signaling] protocol) 
	d.      Use of existing transport protocol(s) depending on the
needs of the p2p protocol 
	e.      Use of existing security protocol(s) depending on the
needs of the p2p protocol 

	If we agree with the above, we can then see where DHT and other
algorithms will stand, and how we should address all aspects of p2p
protocol in a consistent way taking some little baby steps in the
beginning.

	Best regards,

	Radhika

	-----Original Message-----
	From: [email-masked] [mailto:[email-masked]]
	Sent: Tuesday, November 01, 2005 2:29 PM
	To: David A. Bryan; Roy, Radhika (AEAD); Eunsoo Shim
	Cc: [email-masked]
	Subject: RE: [p2p-sip] dhts

	I agree with David.

	I think we could standardize a negotiation framework

	(which is really a capabilities advertisement mechanism)

	along with rules for how to select between alternatives.

	Along this line, I am thinking that the hierarchical P2P network

	discussed in a separate thread on this list (and the referenced
paper)

	is looking increasingly attractive.

	It allows different groups of peers to use different DHT
algorithms.

	Say for example, one group of peers (group A) wishes to use
algorithm X,

	while another group (group B) wishes to use algorithm Y, where
both X

	and Y

	are advanced DHT algorithms. If all nodes also speak some basic

	P2P algorithm Z, then we have a hierarchy, with group A nodes
using

	algorithm X

	internally, group B nodes using algorithm Y internally, and the
two

	groups themselves

	being treated as two nodes in a second level, which speaks
algorithm Z.

	Note that algorithm Z does not have to scale to lots of nodes,
since

	at its level there are only two: the node representing group A
and the

	node representing

	group B. 

	How groups A and B form are good questions. Does a node belong
to group

	A

	simply because it speaks protocol X, or does group A has some
other

	natural

	cohesive grouping? For example, do a bunch of nodes speaking
David's

	SoSimple

	P2P protocol find each other through some (external?) mechanism,

	and a bunch of nodes speaking the Nimcat P2P protocol find each
other

	through

	another mechanism, and then the two groups talk using protocol
Z?

	If others agree with me that a hierarchical approach is the way
to go,

	then I think that we might be able to:

	- Standardize a framework for hierarchical P2P networks

	- Standardize a negotiation mechanism for the P2P protocol being
used in

	a group

	- Standardize a simple protocol Z as the default P2P protocol

	I agree with David's comment that the pattern (and format) of
messages

	used

	in one P2P protocol may differ quite a bit from the messages
used in a

	different

	protocol. I am not sure how successful we would be if we tried
to

	standardize

	(for example) the message format, and leave only the algorithm
open.

	- Philip

	> -----Original Message-----

	> From: [email-masked] 

	> [mailto:[email-masked]] On Behalf Of David A.
Bryan

	> Sent: November 1, 2005 11:59

	> To: Roy, Radhika (AEAD)

	> Cc: [email-masked]

	> Subject: Re: [p2p-sip] dhts

	> I think this is the spirit of the thread, but a warning that
in

	> practice getting this together may be quite difficult, since
different

	> types of p2p implementations exchange different information
between

	> nodes for admission and upkeep of the overlay.

	> I think if we take this approach, the negotiation of a p2p
mechanism

	> and the implementation thereof (how p2p information is
conveyed

	> between nodes) will have to be two independent things, and I
doubt we

	> can standardize how the information is conveyed between nodes
in a way

	> that doesn't take into account what algorithm is being used.
We may

	> need a negotiation mechanism and then different "standards"
for how

	> the nodes maintain the overlay, since the information
contained in

	> messages and even the pattern and reason for messages
exchanged

	> between nodes can vary greatly for different p2p mechanisms.

	> David

	> On 11/1/05, Roy, Radhika (AEAD) <[email-masked]>
wrote:

	> > So, the logical conclusion seems to be as follows:

	> > 1. P2P protocol will be algorithm agnostic

	> > 2. P2P protocol will allow capabilities to negotiate any 

	> algorithm to be

	> > used among the respective peers

	> > 3. P2P scheme will standardize couple of algorithms that can
be

	> > negotiated among the peers starting with a simple one first

	> > It appears that P2P protocol scheme should be flexible
enough to use

	> > algorithms and others per-(each)-peer basis.

	> > To extend this further, it may also be said for transport
(reliable,

	> > unreliable) and security (transport layer, IP layer) that
the P2P

	> > protocol should also use the same principle.

	> > Is that the right summary of this thread so far?

	> > Best regards,

	> > Radhika

	> > -----Original Message-----

	> > From: [email-masked]

	> > [mailto:[email-masked]] On Behalf Of Eunsoo
Shim

	> > Sent: Tuesday, November 01, 2005 11:15 AM

	> > To: David A. Bryan

	> > Cc: [email-masked]

	> > Subject: Re: [p2p-sip] dhts

	> > Standardizing a DHT sounds somewhat overwhelming to me.

	> > But if we put it as standardizing (or writing an 

	> experimental epec of )

	> > a DHT for SIP-based Internet Telephony, Presence and 

	> Instant Messaging

	> > (i.e., for specific target applications), the task sounds
more

	> > approachable and I feel more comfortable. And I think we 

	> have no choice

	> > but to specify one or more DHTs for P2P SIP. Otherwise, we 

	> won't be able

	> > to provide interoperability.

	> > I also agree that we should start with simple algorithms. 

	> It is a good

	> > idea to support negotiation about P2P algorithms.

	> > Regards,

	> > Eunsoo

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