[190132] in North American Network Operators' Group
Re: Barefoot "Tofino": 6.4 Tbps whitebox switch silicon?
daemon@ATHENA.MIT.EDU (Jennifer Rexford)
Thu Jun 16 07:55:00 2016
X-Original-To: nanog@nanog.org
From: Jennifer Rexford <jrex@CS.Princeton.EDU>
In-Reply-To: <CAD6AjGTVtQwDk+Tw2St+X2eQzWouTaBMfjZJAd+kM80QFoyiCQ@mail.gmail.com>
Date: Thu, 16 Jun 2016 07:54:54 -0400
To: Ca By <cb.list6@gmail.com>
Cc: "nanog@nanog.org" <nanog@nanog.org>
Errors-To: nanog-bounces@nanog.org
> I do think p4 is very interesting, but is it really much different =
from
> openflow? Which...umm ... Did not succeed in the market.
P4 is quite different from OpenFlow. The various generations of the =
OpenFlow specification assume a fixed-format packet header with an ever =
increasing number of header fields (from 12 in OF 1.0 to 41 in OF 1.4), =
a fixed set of packet-processing actions, and so on. P4 allows =
programmable parsing and flexible match-action processing. In P4, the =
program tells the data plane how to act; in OpenFlow, the way the data =
plane can act is =E2=80=9Cbaked=E2=80=9D in advance. So, OpenFlow 1.x =
can be one of many *programs* you can write in P4, whereas many other P4 =
programs can exist. For some discussion of the differences, see
Clarifying the differences between P4 and OpenFlow
http://p4.org/p4/clarifying-the-differences-between-p4-and-openflow/ =
<http://p4.org/p4/clarifying-the-differences-between-p4-and-openflow/>
=E2=80=94 Jen
