Sent: 01 August, 2007 15:28
Subject: [Dime] First results on Diameter vs.
RadSec patent
research:EP1147635
Hello all,
(sorry for cross-posting, this may also be of
interest for dime)
when presenting the RadSec draft in IETF69
Chicago, I
mentioned the patent claims of Nokia concerning
Diameter. As a
reaction, some participants claimed that RadSec
itself
implements a subset of the Diameter features and
may very well
itself be subject to these patents. So I started
an
investigation in this respect.
I started the research myself by grabbing a copy
of patent
EP1147635 by Nokia, which is claiming to affect
Diameter. My
focus of the patent's examination was whether
this patent
might also affect RadSec.
The content of this patent is, in short, that
packets on a
network get tagged as "possible duplicate" on
retransmission
in order to make the endpoint aware that the
received content
may be a duplicate of a previous packet. It also
provides a
mechanism to correlate the multiple copies even
when the
packets took different paths through the
network.
Diameter does exactly that, described in section
5.5.4
"Failover and Failback Procedures" of RFC3588: a
bit in the
Diameter header, the "T" bit, is set whenever a
Diameter
packet needed to be retransmitted. Also, Diameter
packets
carry an end-to-end identifier that makes it
possible to
identify duplicates.
This means that at least from my point of view,
Nokia's claim
concerning Diameter is true. Every implementation
of the
Diameter base protocol will use the patented
technology and
needs to either license it or will violate
it.
(Note: I am not a lawyer. This is just my
interpretation;
consider my knowledge being
"Slashdot-level").
From the wording in this section 5.5.4 and the
explanation of
the T bit in chapter 3, it seems that setting the
T bit is
mandatory on retransmissions, so adhering to the
protocol
specification leaves no room for circumventing
the content of
the patent (e.g., by keeping it 0 at all
times).
Luckily, RadSec does not implement such a
sophisticated
duplicate packet detection algorithm. So, this
particular
patent appears not to be of any concern for
implementors of RadSec.
I will continue investigating the bunch of other
patents and
patent applications relating to Diameter as soon
as I get
copies of them. For reference, here is Nokia's
claim statement
concerning Diameter (as submitted to the IETF IPR
tracker):
----------
Title: Nokia's Statement About IPR Claimed in RFC
3588
Received: January 6, 2004
This is to advise the IETF that Nokia believes
the Nokia
patents: EP1147635 and AU757984, and the related
patent
applications: BRPI0007603-1, CA2360093,
CN00804050.8, FI990102,
JP2000-595452 and US09/903863 may be relevant to
Diameter Base
Protocol RFC3588.
Nokia agrees not to assert those claims in Nokia
above
mentioned patents that apply to the RFC3588 and
are
technically necessary to implement this IETF
standard
specification against any other party in respect
of its
implementation of the specification, provided
that the party
relying on this commitment does not assert its
patents against Nokia.
Regards,
Harri Honkasalo
Director of IPR, Standard Technology
Nokia Corporation
----------
Greetings,
Stefan Winter
--
Stefan WINTER
RESTENA Foundation - Réseau Téléinformatique de
l'Education
Nationale et de la Recherche R&D
Engineer
6, rue Richard Coudenhove-Kalergi
L-1359 Luxembourg