[P2PSIP] Mandatory-to-implement DHTs - a dissenting opinion
Jonathan Rosenberg <jdrosen@cisco.com> Fri, 13 July 2007 21:36 UTC
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Date: Fri, 13 Jul 2007 17:35:39 -0400
From: Jonathan Rosenberg <jdrosen@cisco.com>
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Subject: [P2PSIP] Mandatory-to-implement DHTs - a dissenting opinion
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I've read draft-bryan-p2psip-requirements-00, and have a bunch of comments. But a few items came to mind I wanted to discuss which merit their own threads. First, is the concept of mandatory-to-implement DHT. The requirements document talks a lot about requirements around selecting a mandatory to implement DHT. Its something we've discussed in the meeting and on the list. I think everyone agrees also that we need to allow for multiple DHT and all of the recent protocol proposals support it. However, I do not think we should have a mandatory-to-implement DHT at all. There are several reasons for this. First of all, its important to understand the reason why IETF has mandatory-to-implement functionality in its protocols. The one and only reason is that it ensures interoperability. It ensures that, independent of the optional features selected by a pair of entities, when you connect them together, they can still interoperate. This property will NOT be retained with a mandatory-to-implement DHT. Once the ring forms, the DHT protocol is chosen and locked. Thus, if any DHT besides the 'mandatory-to-implement' one has been selected for the DHT, a new node not supporting that DHT will not be able to join the ring even if it implements the mandatory-to-implement one. Thus, the entire purpose of mandatory-to-implement is eliminated - we don't actually get interoperability. Indeed, to get this kind of interoperability, we'd need to pick one and only one DHT that ever gets used with p2psip. I think that is a mistake. This is an evolving area and is one where agility is important. Instead, what I think happens is that a 'provider' that deploys a p2p network will need to pick a DHT, and make sure that the clients all support that DHT. This is something the market should drive, not us. Secondly, I think its important to realize that we are picking up work in an area that is well trod. There are lots and lots of papers and protocols and software written around P2P networks. I don't think anyone looks at an IETF protocol and says, "IETF are the guys who know about DHTs, lets go with their recommendation". What IETF is really good at, and what this group has expertise in, is SIP, and on designing good, scalable protocols in general - things that have security, extensibility, good performance, and so on. So I think the greatest value we can bring to the table is to create a protocol that allows others to take DHTs and easily turn them into a real wire protocol that you can actually deploy, on the Internet, to support SIP and ideally other things too. Interestingly, this is exactly what all of the protocol proposals do. That kind of focus goes hand-in-hand with saying, let someone else figure out which DHT to use. I think its perfectly reasonable for us, and for others, to write documents on how to use our protocol with various DHTs. But I think we should be out of the business of picking one or recommending one (or ones) to be used. -Jonathan R. -- Jonathan D. Rosenberg, Ph.D. 600 Lanidex Plaza Cisco Fellow Parsippany, NJ 07054-2711 Cisco Systems jdrosen@cisco.com FAX: (973) 952-5050 http://www.jdrosen.net PHONE: (973) 952-5000 http://www.cisco.com _______________________________________________ P2PSIP mailing list P2PSIP@ietf.org https://www1.ietf.org/mailman/listinfo/p2psip
- [P2PSIP] Mandatory-to-implement DHTs - a dissenti… Jonathan Rosenberg
- RE: [P2PSIP] Mandatory-to-implement DHTs - a diss… Henry Sinnreich
- Re: [P2PSIP] Mandatory-to-implement DHTs - a diss… David A. Bryan
- Re: [P2PSIP] Mandatory-to-implement DHTs - a diss… Ted Hardie
- Re: [P2PSIP] Mandatory-to-implement DHTs - a diss… Emil Ivov
- Re: [P2PSIP] Mandatory-to-implement DHTs - a diss… Henning Schulzrinne
- Re: [P2PSIP] Mandatory-to-implement DHTs - a diss… Ted Hardie
- Re: [P2PSIP] Mandatory-to-implement DHTs - a diss… Medhavi Bhatia
- RE: [P2PSIP] Mandatory-to-implement DHTs - a diss… Krishna Sankar (ksankar)
- Re: [P2PSIP] Mandatory-to-implement DHTs - a diss… David A. Bryan
- Re: [P2PSIP] Mandatory-to-implement DHTs - a diss… David A. Bryan
- Re: [P2PSIP] Mandatory-to-implement DHTs - a diss… Wei Gengyu
- RE: [P2PSIP] Mandatory-to-implement DHTs - a diss… Kundan Singh
- RE: [P2PSIP] Mandatory-to-implement DHTs - a diss… David Barrett
- RE: [P2PSIP] Mandatory-to-implement DHTs - a diss… Kundan Singh
- Re: [P2PSIP] Mandatory-to-implement DHTs - a diss… David Barrett
- Re: [P2PSIP] Mandatory-to-implement DHTs - a diss… Henning Schulzrinne
- Re: [P2PSIP] Mandatory-to-implement DHTs - a diss… Bruce Lowekamp
- Re: [P2PSIP] Mandatory-to-implement DHTs - a diss… David Barrett
- Re: [P2PSIP] Mandatory-to-implement DHTs - a diss… Henning Schulzrinne
- RE: [P2PSIP] Mandatory-to-implement DHTs - a diss… David Barrett
- RE: [P2PSIP] Mandatory-to-implement DHTs - a diss… Roy, Radhika R.
- Re: [P2PSIP] Mandatory-to-implement DHTs - a diss… Eunsoo Shim
- Re: [P2PSIP] Mandatory-to-implement DHTs - a diss… Eunsoo Shim
- Re: [P2PSIP] Mandatory-to-implement DHTs - a diss… Eunsoo Shim
- RE: [P2PSIP] Mandatory-to-implement DHTs - a diss… Roy, Radhika R.
- RE: [P2PSIP] Mandatory-to-implement DHTs - a diss… Roy, Radhika R.
- RE: [P2PSIP] Mandatory-to-implement DHTs - a diss… Henry Sinnreich
- Re: [P2PSIP] Mandatory-to-implement DHTs - a diss… Henning Schulzrinne
- Re: [P2PSIP] Mandatory-to-implement DHTs - a diss… David A. Bryan
- RE: [P2PSIP] Mandatory-to-implement DHTs - a diss… David Barrett
- Re: [P2PSIP] Mandatory-to-implement DHTs - a diss… David A. Bryan
- Re: [P2PSIP] Mandatory-to-implement DHTs - a diss… Henning Schulzrinne
- RE: [P2PSIP] Mandatory-to-implement DHTs - a diss… David Barrett
- Re: [P2PSIP] Mandatory-to-implement DHTs - a diss… Bruce Lowekamp
- Re: [P2PSIP] Mandatory-to-implement DHTs - a diss… David Barrett
- Re: [P2PSIP] Mandatory-to-implement DHTs - a diss… Ted Hardie
- Re: [P2PSIP] Mandatory-to-implement DHTs - a diss… Ted Hardie
- RE: [P2PSIP] Mandatory-to-implement DHTs - a diss… He, Jingtong
- Re: [P2PSIP] Mandatory-to-implement DHTs - a diss… Henning Schulzrinne
- RE: [P2PSIP] Mandatory-to-implement DHTs - a diss… David Barrett
- RE: [P2PSIP] Mandatory-to-implement DHTs - a diss… Henry Sinnreich
- RE: [P2PSIP] Mandatory-to-implement DHTs - a diss… David Barrett
- Re: [P2PSIP] Mandatory-to-implement DHTs - a diss… Jonathan Rosenberg
- Re: [P2PSIP] Mandatory-to-implement DHTs - a diss… Jonathan Rosenberg
- Re: [P2PSIP] Mandatory-to-implement DHTs - a diss… Jonathan Rosenberg
- Re: [P2PSIP] Mandatory-to-implement DHTs - a diss… Henning Schulzrinne
- Re: [P2PSIP] Mandatory-to-implement DHTs - a diss… Bruce Lowekamp
- RE: [P2PSIP] Mandatory-to-implement DHTs - a diss… Roy, Radhika R.
- RE: [P2PSIP] Mandatory-to-implement DHTs - a diss… Roy, Radhika R.
- RE: [P2PSIP] Mandatory-to-implement DHTs - a diss… Brian Rosen
- RE: [P2PSIP] Mandatory-to-implement DHTs - a diss… Ted Hardie
- RE: [P2PSIP] Mandatory-to-implement DHTs - a diss… Brian Rosen
- RE: [P2PSIP] Mandatory-to-implement DHTs - a diss… Ted Hardie
- RE: [P2PSIP] Mandatory-to-implement DHTs - a diss… Brian Rosen
- Re: [P2PSIP] Mandatory-to-implement DHTs - a diss… Bill Mccormick