1. Link-layer Hints for Movement Detection Alper Yegin IETF 57, Vienna July 18th, 2003

2. Detection and Reaction Cycle Collect clues –Link-layer hints –Network-layer hints Make determination Change configuration –Use some of the network-layer hints, learn others

3. Network-layer Can… Detect presence of a new router (or absence of an existing router) –Receive unsolicited router advertisements –Solicit advertisements Detect presence or absence of a DHCP server –Unsolicited/solicited Detect presence or absence of an “on-link” prefix –Observe traffic (promiscuous mode)

4. Link-layer Could… Tell IP when link is torn down (link down) –Asynchronous notification Tell IP when link is established (link up) –Asynchronous notification Tell IP the link id when asked –E.g.: SSID with IEEE 802.11 More fancy ones ….

5. Process Passively collect hints –New prefixes advertised –Prefix goes stale –Prefix part of IP addresses change –Link up received Actively collect hints –Send router advertisement –Learn the current link id Make the determination

6. Notes Who receives the L2 hints –Preferably host, but network-side (e.g., router) is useful too Interpreting detection of a new link –Not necessarily means configuration change for network-layer Security concerns

7. What Can We Do at IETF? Define useful/practical link-layer hints –Details are link-layer specific, so use abstraction www.yegin.org/alper/draft-manyfolks-l2-mobilereq-02.txt –Communicate with other SDOs IEEE Handoff ECSG –“ Summary of ongoing / proposed work in SEAMOBY, TRIGTRAN and IRTF's Micro Mobility initiative and requirements they might bring to the Handoff SG” 3GPP/3GPP2 Define two movement detection schemes –When L2 hints available –When L2 hints are NOT available (partial availability?) Others?