Transcript PPT Version
Link-Layer Hints for Detecting Network Attachments Alper Yegin, Eric Njedjou, Siva Veerepalli, Nicolas Montavont, Thomas Noel Objective • draft-yegin-dna-l2-hints-00.txt • Identify how link-layer can assist DNA algorithms – Catalogue existing link-layers and their capabilities • • • • GPRS cdma2000 IEEE 802.11 … – Define an abstraction GPRS ACTIVATE PDP CONTEXT REQUEST MN ACTIVATE PDP CONTEXT ACCEPT (allocated IP address, QoS parameters) SGSN GGSN IP connectivity MN Mobile Node SGSN GPRS Access Point GGSN GPRS Access Router cdma2000 MS BS_1x BS_2x BS_1y PCF_1x PCF_2x PCF_1y PDSN_x PDSN_y MS hands off to BS_2x No change in nw layer configuration MS hands off to BS_1y New PPP - NW layer configuration change Radio Link Protocol (RLP) A8 GRE Tunnel A10 GRE Tunnel Point to Point Protocol (PPP) MS: Mobile Station BS: Base Station PCF: Packet Control Function PDSN: Packet Data Serving Node IEEE 802.11 New Access Router New Access Point Active scanning Mobile Probe Request Probe Response Passive scanning Beacon Authentication Authentication Assoc. Request Assoc. Response Router Solicitation Router Advertisement Triggers and Hints… • Event notifications from the link-layer will trigger the DNA algorithm: – Link up: • PDP context activated on GPRS • PPP established on cdma2000 • (re)association or secure association on IEEE 802.11 Triggers and Hints… • Hints may be optionally provided along the triggers, which may help optimize the DNA process – The IP address is provided during PDP context activation on GPRS – Same with the PPP on cdma2000 – IEEE 802.11… not straight forward Hints in IEEE 802.11 • No L3 configuration in L2 • Need for an identifier to associate links with networks (configurations) – BSSID (L2 address of AP)? • No one-to-one mapping to a network – SSID (service set identifier)? • Same SSID might be used across a routed network. • SSID does not mean much when the network is selected during the authentication phase (dynamic VLAN assignment) • Any useful hints for DNA without modifying IEEE 802.11?