Re: [RAI] Draft on P2P architectures

[Gonzalo Camarillo <[e-mail]>]

Hi Dan,

thanks for your comments. Answers inline:

Dan York wrote:
> Gonzolo,
> 
> On Feb 23, 2009, at 9:40 AM, Gonzalo Camarillo wrote:
> 
>> the IAB has just submitted the following draft:
>>
>> http://www.ietf.org/internet-drafts/draft-iab-p2p-archs-00.txt
>>
>> Comments are welcome.
> 
> Overall I think this is a useful document to help people understand what 
> is going on with P2P architectures.  A couple of comments:
> 
> - I'll second Dan Wing's comment that the draft should include some 
> mention of Bittorrent, given the wide usage of that P2P protocol.   Many 
> sites have info about torrent usage - some good pointers off of the 
> Wikipedia page: http://en.wikipedia.org/wiki/BitTorrent_(protocol)  A 
> mention (and links) would be good if for no other reason than to point 
> people interested in learning more about P2P architectures to the wealth 
> of info out there about torrent-based networks.

I have added references to BitTorrent now.

> - In section 2, it would seem to me beneficial to provide some further 
> examples of applying the P2P definition beyond simply DNS, SIP and 
> P2PSIP.  I realize that the authors may be trying to constrain 
> discussion to items directly handled by the IETF, but there are 
> significant P2P deployments out there on the Internet (Bittorrent being 
> one of them, but there are many others) that could be interesting to 
> discuss in the document to help readers understand how the P2P 
> definition can relate to deployed P2P systems.

I have added a subsection in Section 2 about BitTorrent.

> - When providing guidance on whether a P2P architecture is appropriate, 
> it may be useful to encourage developers to think about the *type* of 
> endpoints that will most likely be part of their network.  I believe it 
> was Xiao Lin in the P2PSIP mailing list who suggested that there were 
> three types of endpoints to consider: fixed (e.g desktop computers), 
> mobile (e.g. mobile phones) and mixed (e.g. laptops).  Fixed endpoints 
> or laptops may be good candidates for *peers* in a P2P environment, 
> whereas mobile handsets may not be. (But they could be as "clients", see 
> next bullet.)

The reason why mobile handsets may not be a good candidate for peers is 
that they have limited battery life... and that point was already 
discussed in the document (in Section 7 when talking about energy 
consumption).

> - The mobility discussion in the P2PSIP mailing list has highlighted 
> that there may be some P2P environments where some nodes connect to the 
> P2P overlay to access services but do not participate as full peers, 
> perhaps because they don't have the processing capabilities or perhaps 
> because they are too mobile and would create too much churn in the 
> overlay with their movement.  They are simply "clients" of the P2P 
> network.  It may be useful to mention this concept in this draft.

I have introduced this concept in Section 2 now.

> - For the security section, I know there are several Internet-Drafts out 
> there that get into P2P security issues and it may be useful to point to 
> those drafts from this document.  One of them that I know of (because I 
> am involved with it) is for P2PSIP and is at: 
> http://tools.ietf.org/html/draft-matuszewski-p2psip-security-requirements.  
> (The draft is currently being refactored to align with the newest main 
> P2PSIP specification and to split some pieces out into a separate 
> document, but the content there may still be of interest.)

I have had a look at a few drafts that deal with P2P issues. However, I 
have tried to minimize references to work in progress (especially to 
individual contributions). The only draft that is currently referenced 
is ICE.

> - Also, the security section mentions does not mention (that I could 
> see) that dealing with some of these security issues is precisely why 
> some P2P networks will implement centralized enrollment/authentication 
> servers (which were mentioned briefly back at the beginning of section 
> 3).  If you look at Skype, for example, they maintain tight centralized 
> control over joining the P2P overlay through their enrollment servers. 
> You have to have a valid Skype username and password in order for Skype 
> to connect to the P2P cloud.

This is mentioned in the Security Considerations section in the context 
of the Sibil attack.

> Again, I think a document like this is quite a useful contribution to 
> the interest out there in P2P architectures and I thank the IAB for 
> putting it together.

Thanks for your comments. I will be submitting a new revision of the 
document including them shortly.

Cheers,

Gonzalo