Editors' note: These minutes have not been edited. Montreal IETF Proceedings Routing Area UDLR BOF Minutes of the UniDirectional Link Routing BOF session, Friday, June 28 (one session) Reported by: Walid Dabbous, INRIA Sophia Antipolis The goal of the meeting was to present and discuss the support of unidirectional link in Internet routing protocols. Walid Dabbous started by presenting the general problem: How to offer a low-cost, high bandwidth connection to the Internet based on broadcast satellite networks. As low-cost DVB hardware is receiver only, the support of these satellite networks within the Internet requires changes in common routing protocols. Two access modes were described, namley the "basic access" mode where each receiver has a satellite dish, and the "subnetwork access" mode where the satellite dish is installed on a subnetwork router. The subnet could be e.g. an ISP net receiving Mbone traffic on the satellite link The problem in the basic access mode is the dynamic mapping IP addresses onto media addresses (on the unidirectional satellite network). It was proposed to investigate the feasibility of a solution based on the use of a static management table, and to compare it to a solution based on a modification of ARP. The problem in the subnet access mode is to support dynamic routing even though it is not possible to receive routing update packets from the receivers-only DVB hardware on the satellite subnetwork. Two solutions for this problem were presented. The first one by Emmanuel Duros from INRIA, in which he proposed modifications for RIP, OSPF and DVMRP to support dynamic routing in the presence of unidirectional links. The main idea is to allow routing udpates to be sent to the sources sending on the satellite network (the feeds) via regular Internet connections. Authentication is used to allow routing updates packets received on an interface different from the one concerned by them to be taken into account. The solutions are described in detail in ftp://zenon.inria.fr/rodeo/udlr/doc/draft-ietf-general- udlr-00.txt Another solution was presented by Yongguang Zhan from Hughes Research Laboratories. This solution is based on the set up a tunnel to the feeds and to send routing packets on it. This requires no changes to the routing protocols, but may be harder to manage. There were also a presentation made by Jun Murai from the WIDE project, on WISH (Wide Internet With Harmonisation). In his presentation, Jun described the Internet satellite based network installed in Japan. No routing solutions were supported. Jun expressed his interest in testing the proposed solutions on WISH. Henry Sinnreich from MCI addressed the problem of link layers. He said Ethernet like link layer are preferred (instead of MPEG2-like transport). Harry Hakulinen from Nokia Research proposed to write an internet draft proposal to explain how to encapsulate IP packets on top of DVB transport. Intersting questions, remarks and comments were raised and will be discussed on the udlr mailing list udlr@sophia.inria.fr. To subscribe send e-mail to: udlr-request@sophia.inria.fr Archive is at: ftp://zenon.inria.fr/rodeo/udlr/archive.txt The main decisions at the end of the BOF were to proceed both INRIA and Hughes solutions in a coordinated way. These solutions are being implemented and it is expected that INRIA experiment its solution on a European scale (with the MERCI project partners) using DVB cards and satellite capacity provided by Eutelsat. Another BOF session in San Jose will be requested to present the resutls. Decision on the possible start of a Working Group will be taken after this second BOF session.