[137813] in North American Network Operators' Group
Re: quietly....
daemon@ATHENA.MIT.EDU (Owen DeLong)
Sat Feb 19 21:19:13 2011
From: Owen DeLong <owen@delong.com>
In-Reply-To: <4D601D19.60902@dcrocker.net>
Date: Sat, 19 Feb 2011 18:15:25 -0800
To: dcrocker@bbiw.net
Cc: North American Network Operators Group <nanog@nanog.org>
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
My understanding of peer-to-peer was that it indicated that all hosts =
had
equal ability to originate or terminate (as in accept, not as in end) =
sessions.
That is, the role of client or server is defined by the choice of the =
application
and/or software on the host and not by the network.
IP is a peer to peer network because all nodes are equal at the protocol
level. IP does not make a protocol-level distinction between clients or
servers.
See: http://en.wikipedia.org/wiki/Peer-to-peer
Noting specifically from =
http://en.wikipedia.org/wiki/Client-server#Comparison_to_peer-to-peer_arch=
itecture
It would appear to me that IP is, by definition peer to peer while
TCP seems inherently client-server in most implementations and
UDP is ambiguous and can be used in either mode, as in DNS where
a recursive resolver operates simultaneously as both a server and
a client or peer and an authoritative server with secondaries also
operates simultaneously as a server and as a peer.
You are correct about the peer to peer or not nature of an architecture
being possibly different at different layers, but, I don't think you are
right in saying that having routers in between makes two IP nodes
not peers.
Owen
On Feb 19, 2011, at 11:42 AM, Dave CROCKER wrote:
>=20
>=20
> On 2/19/2011 10:11 AM, kmedcalf@dessus.com wrote:
>>=20
>> And that has nothing to do with whether a protocol is a peer protocol =
or not.
>> IP is a peer-to-peer protocol. As SMTP is implemented over IP, it is =
also a
>> peer-to-peer protocol.
>=20
>=20
> At each layer of an architecture, the question of whether a mechanism =
is peer to
> peer can be newly defined. Even within a layer it can be, depending =
upon
> configuration choices.
>=20
> IP is typically /not/ peer to peer, since getting from the originating =
host to
> the target host is typically mediated by many routers. That is the =
essence of
> /not/ being peer to peer.
>=20
> One layer up, we find that TCP typically /is/ peer-to-peer.
>=20
> "SMTP" as a one-hop email transmission protocol is peer-to-peer from =
the SMTP
> client to the corresponding SMTP server. However email exchange from =
an
> author's MUA to a recipient's MUA is, again, the essence of /not/ =
being peer to
> peer. It is typically massively mediated by lots of different email =
servers.
>=20
> One could configure two MUAs to talk with each other 'directly' using =
SMTP, but that's never done.
>=20
> Instant message services similarly are not peer-to-peer technical =
terms.
>=20
> d/
>=20
> --=20
>=20
> Dave Crocker
> Brandenburg InternetWorking
> bbiw.net
