50 th IETF BURP BOF, March 20, 2001 Applicability of a User Registration Protocol Yoshihiro Ohba (Toshiba America Research, Inc.) Henry Haverinen (Nokia)

50 th IETF BURP BOF, March 20, 2001 Access control issue (1) Managed access control • L2 access control basically provides "all-or-nothing" access control • Simple and useful for some cases (DSL, Cable) • Flexible access control would also be useful in certain cases (network access in public area), e.g., • Allow any user to get access to a web site within the edge subnet to get local area guide information • Deny unauthorized user to access beyond the edge subnet

50 th IETF BURP BOF, March 20, 2001 Access control issue (2) Multi-homing • A host may associate with multiple Access Routers (ARs) • If all ARs belong to the same AAA domain, performing AAA per AR may not be a good idea • If each AR belongs to a different AAA domain, AAA per AR would be necessary • These ARs may speak IPv4 only, IPv6 only, or both. • A host may have multiple interfaces • If all interfaces belong to the same AAA domain, performing AAA per interface may not be a good idea AR1 AR2 H H AR1

50 th IETF BURP BOF, March 20, 2001 AAA application protocol issue • AAA application protocols: MIP, SIP,... • Each protocol design started without AAA (base spec.) • Later on, AAA interaction is considered • Fortunately, no modification is needed for the base spec. in terms of the last two 'A's (good for modularity) • Need consideration to deal with the first 'A' • How to establish an SA with "out of the blue" client? • MIPv4 has AAA extention to carry registration keys •It would be very nice if a protocol can be "AAA-ready" without any modification to its base spec. • Coupling user registration with key distribution

50 th IETF BURP BOF, March 20, 2001 BURP (Basic User Registration Protocol) • Is a client-server type protocol that • Performs user registration to the visiting AAA domain • Works with Diameter/RADIUS, leveraging AAA infrastructure in the network based on the information gathered in the registration phase • Is a light-weight, application layer protocol that is applicable • To various devices (e.g., PDA, cellular, laptop) without modifying kernel or device drivers • To flexibile access control • To multi-homing environment •Is is also used for key distribution for AAA application protocols

50 th IETF BURP BOF, March 20, 2001 Thank you!

50 th IETF BURP BOF, March 20, 2001 Example of BURP applicability to SIP Step 1: The user performs user registration by using BURP Step 2: If step 1 is successful, authorization information is pulled from AAA infrastracture. • The information includes application specific one such as: a SIP registration key • Also, access control parameters will be set to access routers Step 3: The user run SIP. • Thanks to the previous steps, authentication for SIP registration can be done w/o contacting to AAA. (The example can be applied to other protocol "X" by replacing "SIP" with "X".)

50 th IETF BURP BOF, March 20, 2001 User Terminal BURP ServerSIP Server/Proxy AAA infrastracture in the core network

50 th IETF BURP BOF, March 20, 2001 Basic Part of Each Application Protocol (independent of AAA) Possible architecture AAA Protocol Entity (Diameter/RADIUS) SIP Server Mobile IP Mobility Agent AR/AP BURP Server (Registration Agent) BURP Client SIP Client Mobile IP Mobile Node... User Terminal Network L2 Auth. Client AAA info. (incl. registratin keys) AAA info. (incl. Registration keys) BURP messages AAA Protocol Entity