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 From: harri.t.honkasalo@nokia.com 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 email: stefan.winter@restena.lu Tel.: +352 424409-1 http://www.restena.lu Fax: +352 422473
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