CS9 Mobile Computing solutions Outline Dr. yman bdel-hamid Computer Science Department Virginia Tech Mobile IPv Micro-mobility Local-area Mobility Solutions Within the Mobile IP framework Regional Framework (MIP_RR) Local and Indirect Host-based forwarding schemes Cellular IP (Columbia University) WII (ell Labs) Multicast-based schemes ssign a scoped multicast address within the foreign domain Regional Framework (MIP_RR) / Home Regional G 9 {,,, and }: Home when the first enters the foreign domain. {, }: Regional with a local handoff from to. dvertises {,, } {,, 9, and }: Home involving a local handoff from to.
Regional Framework (MIP_RR) / Regional Framework (MIP_RR) / The old relays the U message, received from the new, upwards in the hierarchy (to its father ) specifying itself as the care-of address of the. The father performs the following steps delete its s visitor entry, create a binding cache entry for the with care-of address the child that sent the U message, relay the U message upwards in the hierarchy, and send back a binding acknowledge message to its child Tunneling consistency mechanism to clear visitor entries in old path Reg. Req. Reg. Req. U G Reg. Req. with PNE Crossover U U Regional inding update message Local and Indirect Cellular IP / :Home gent : Foreign gent Local Indirect Home Network Home Network Secure tunnel Secure tunnel Foreign Network nchor Foreign Network nchor Cellular IP and Mobile IP tunnel Wireless access network Local handoffs Gateway Router Global Internet with Mobile IP Global mobility S S Wireless access network S Local handoffs S S Mobile IP Cellular IP Wireless access network model
paging update packets paging packet routed to using paging caches Data packets for Gateway Router Gateway Router C C Cellular IP / : from G : from G D D : from F E, D have paging caches F Paging update packet (routed hop-by-hop towards the GW) : from F F E responds with a routeupdate packet which configures routing caches along the way to the GW 9 WII / Handoff-ware Wireless ccess Internet Infrastructure Uses specialized path setup schemes which install host-based forwarding entries in specific routers to handle intra-domain micro-mobility defaults to using mobile IP for inter-domain macro-mobility requires that obtains a co-located care of address within a domain, nevertheless is required to register with a S within the domain to be able to better handle handoffs sends path setup update messages during power up and after handoffs HR Home Domain R notified of co-located care of address FR Foreign Domain HR: Home Domain Root Router FR: Foreign Domain Root Router domain model within WII WII / Multicast and Mobility / Router ():... ():... C C Router Router ():... (): Default ():... ():... C C Old S New S ():... (): Default ():... ():... IP:... Forwarding path setup scheme ( can listen/transmit to only one S) Router ():... ():... Old S ():... ():... Router ():... ():... C C Router C K C C New S IP:... Non-Forwarding path setup scheme ( can listen/transmit to multiple S) The Deadalus pproach (erkeley, 99) maintains the concept of Mobile IP pre-assigned a multicast address by encapsulates any packets destined to and forwards them over the pre-assigned multicast group informs nearby ase Stations about multicast group and controls forwarding/buffering of packets at Ss through a control protocol
Multicast and Mobility / Multicasting-based Mobility Solution (99) multicast sole mechanism to provide addressing and routing services to s each is assigned a unique multicast IP address (globally unique) approach affects a number of existing protocols such as TCP, ICMP, RP, IGMP Multicast and Mobility / Fast Handoffs for Wireless Networks (999) foreign domain arranged as a two level hierarchy with a domain at the root and base stations as leafs. assigned a multicast address within the foreign domain by the domain (centralized server) domain becomes forwarding agent for all s (single point of failure, bottleneck) does not discuss details of multicast address allocation or effects on multicast routing Outline cooperating hierarchies local-area mobility support framework Cooperating Foreign gents Hierarchies / local-area mobility support framework Efficiently handle local-area movement scenarios within a foreign domain through cooperation between hierarchies Provide authentication and replay protection for all protocol messages Not specific to any access technology Explore the hierarchy structure to enhance processing
Cooperating Foreign gents Hierarchies / Model hierarchy model Foreign Domain G Foreign gent dvertisement Intra-hierarchy handoffs Inter-hierarchy handoffs cooperation n Regional s {, G} @RealmX {, G} @RealmX dvertise the IP address (if not private) for legacy s Hide the hierarchy structure Critique of MIP_RR s tunneling consistency Regional s Framework / Old R j In old path New R i in route to crossover Crossover (can be G) Requires smooth handoff mechanism Potential race condition if U from old path reaches crossover before the from new path R Crossover U (D old-crossover ) Request (D new-crossover ) Old Old path D new-old U New path New Request Rreg. Req. Rreg. Reply Dereg. (U) inding ack. Rreg. Req. Rreg. Reply Dereg. (U) inding ack. Rreg. Req. Rreg. Reply Regional messages (Request/Reply) Route Optimization messages (U/inding ack.) Rreg.:Regional Req.:Request ck.:cknowledgement Dereg.:Deregistartion 9
Replay Protection Regional s Framework / Crossover propagates upwards in the hierarchy towards the G a replay protection update message to ensure future successful processing of s by upper Rs in the path This message propagates the new identification value assigned to the by the crossover Used for nonce replay protection and timestamp replay protection Type Reserved Home ddress New Identification Identification Extensions Home s Framework Home s involving local handoffs home is forwarded to the to renew the s mobility binding How about the old path? de mechanism similar to the regional framework would clear the old path, but increases packet loss while waiting for the from the The need to clear the visitor entries on the old path Our solutions KOP approach (Keep Old Path live) SINP approach (Switch Immediately to New Path) Intra- Handoffs: The KOP pproach / Intra- Handoffs: The KOP pproach / U with estimated lifetime, along with new IP address information. Old can tunnel buffered or future packets to new Old Request Old path R New path G Crossover New Request along with new IP address information Request What lifetime is used for the U? U lifetime = Max {home reg. latency, α * remaining reg. lifetime} Where < α <= (we use α =.) Maintain observed home latency at each R How the new information is propagated without the smooth handoff mechanism? enefit from the existence of a hierarchy, an old and new path Propagate new information along new path to crossover, then along old path to old through a local care-of address extension
Intra- Handoffs: The KOP pproach / uthentication and replay protection home would only include home authentication and identification information How can the crossover authenticate the to initiate KOP? includes a local replay protection extension, such that the crossover is capable of ensuring the freshness of its authenticates its using a -G authentication extension Crossover authenticates the before initiating the tunneling consistency mechanism on the new path Intra- Handoffs: The SINP pproach De mechanism (U message with zero lifetime) Old Home Request Old path Regional Reply The crossover switches the tunneling path to the new path before receiving a home. R G Home Request Crossover Home Request New path New Home Request View such s as a truly combined home and regional s The local handoff completion does not have to wait for a from the Performance Evaluation / Performance Evaluation / CH. Mbps ms,. Mbps LD G-,.. G Mbps LD -, Foreign domain,,,,,,, verage lost packets per handoff KOP SINP ase MIP DOP G to delay (in msec) UDP Traffic verage encapsulated packets per HR-LH G to delay (in msec) LD: Link delay Using the KOP approach Simulated Network Topology
Performance Evaluation / UDP Traffic Performance Evaluation / TCP Traffic verage lost packets per HR-LH KOP SINP DOP G to delay (in msec) verage dropped packets per handoff KOP SINP.9........ 9 Playout delay in msec TCP Throughput (M bps) KOP SINP ase MIP DOP......9. G to delay (in msec) Retransmission Ratio KOP SINP ase MIP DOP..... G to delay (in msec) 9 Inter- Handoffs / Inter- Handoffs / One hierarchy in foreign domain is a burden on the G. (single point of failure, maintain routing entries for all s) If multiple hierarchies are deployed, no configurable scalable cooperation is envisioned between hierarchies Reduce the number of required security associations between s in different hierarchies Shield the from the s movement within the foreign domain Routing Zone G G Foreign Domain Configurable Cooperation G Routing Zone G Routing Zone i G i G i Partition foreign domain into routing zones Each routing zone is an independent hierarchy s advertise their own IP address and the G address registers G as its care-of address. G is termed the s HRG (Home-registered G).
Inter- Handoffs / Inter- Handoffs / Configurable Cooperation Cooperation is only allowed between the roots of the hierarchies ( security associations between each pair of Gs) The s advertise two new options in their mobility agent advertisements will this G accept cooperation s from other Gs? will this G send cooperation s on behalf of the? Routing Zone G G Old tunnel Foreign Domain G G New tunnel Routing Zone Routing Zone i G i G i The movement between hierarchies Inter- Handoffs / Inter- Handoffs / Enter foreign domain Home lifetime expiration Home reg. ds from the current or HRG hierarchy Event transition utomatic transition Regional reg. Homeregional D_H or reg. HRE_NDOFF_H reg.: ds: advertisements D_H: ds from another hierarchy HRE_NDOFF_H: Home lifetime expiration while moving to another hierarchy home with a regional data extension The current G attempts to contact the HRG using the information in the regional extension If success, the current G receives tunneled packets for the from the HRG If the HRG does not respond, use the s home credentials to perform a home on behalf of the State Diagram 9
Inter- Handoffs / Regional in G j hierarchy G j G i ('s HRG) If the RZ accepted the regional, the Z j hierarchy is now able to authenticate any future s by the. The home-regional process, in case the RZ is reachable. Inter- Handoffs / Home Regional in G j hierarchy Home G j G i (The 's HRG) ICMP errors Home Home Upon successful, the 's HRG is changed within the foreign domain. The home-regional process, in case the HRG is not reachable. Performance Evaluation / Performance Evaluation / CH. Mbps ms LD: Link Delay UDP Traffic. Mbps G G LD -G (Default is ms) Mbps LD G-G (Default is ms). Mbps G G.,, Foreign domain,,,, Simulated Network Topology. 9, Local-area Network Mbps ms G i, vergae lost packets per handoff NC-Gs/ C-Gs/ NC-Gs/V C-Gs/V -G link delay (msec) vergae lost packets per handoff C-Gs NC-Gs....... G-HRG link delay (msec)
Performance Evaluation / TCP Traffic NC-Gs C-Gs NC-Gs C-Gs TCP Throughput (Mbps).....9. G- link delay (msec) Retransmission Ratio...... G- link delay (msec)