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GLOBECOM 2007. Route Optimization for Large Scale Network Mobility Assisted by BGP. Feriel Mimoune, Farid Nait-Abdesselam, Tarik Taleb and Kazuo Hashimoto. Outline. Introduction Related Work ROB: Route Optimization Assisted By BGP Performance Analysis Conclusion. Introduction.
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GLOBECOM 2007 Route Optimization for Large Scale Network Mobility Assisted by BGP Feriel Mimoune,Farid Nait-Abdesselam,Tarik Taleb and Kazuo Hashimoto
Outline • Introduction • Related Work • ROB: Route Optimization Assisted By BGP • Performance Analysis • Conclusion
Introduction • Considering mobility of an entire network, • it is possible to use Mobile IP to enable mobility for all the devices within the mobile network. • However, this would • require all the devices to be Mobile IP capable and • will incur significant overhead, • i.e, a storm of control packets as every device has to perform Mobile IP functions. • In this paper, we discuss the design of a new scheme to enable IPv6 mobile networks • to perform route optimization by invoking the widely deployed border gateway protocol (BGP).
Related work • The Optimized Route Cache (ORC) scheme • proxy routers intercept packets, destined to the target network prefixes, using the Interior Gateway Protocol (IGP) in the Autonomous System (AS). • then encapsulate the packets and tunnel them to the corresponding MRs. • the upper routers, in the nested mobile network, are • aware of the network prefix information of lower routers and • designed to send them to their ORC (proxy) routers. • modifies the route advertisement (RA) message • fixed routers should be also modified
Related work (cont.) • The NEMO basic support • a bidirectional tunnel between MR and its correspondent HA • MR’s HA intercepts all packets directed to MNNs (Mobile Network Nodes) and tunnels them toward the MR • MNNs outbound packets are also tunneled to the HA in order to bypass ingress filtering • simple and provides complete and transparent mobility to MNNs • triangular suboptimal routing • HA becomes the bottleneck • data packets of nested mobile networks experience pin-ball routing and multiple encapsulations.
Related work (cont.) • Reverse Routing Header (RRH) • record addresses of intermediate MRs into the packet header • only one bidirectional tunnel between the first MR and its HA • avoid packet delivery through all HAs of the intermediate MRs • Although the authors claim that this scheme performs route optimization between a CN and a MR, there is no detailed description on the route optimization operation. • Suffers from lack of a secured binding update mechanism using RRH and • has to modify the RA messages to count the number of intermediate MRs
ROB: Route Optimization Assisted by BGP • BGP is a highly robust and scalable routing protocol, as evidenced by its wide use in the Internet. • An entry in the BGP routing table (Network, Next Hop, Path) • Network field: the network destination address. • Next Hop field: the BR’s IP address that should be used as the next hop. • Path field: composed of a sequence of autonomous system path segments • When changes to the routing table are detected, the BGP routers send information on only changed routed to their neighbors. • We upgrade the entry of the routing table by one more field related to the temporary network prefix (TNP) as (Network, Next Hop, Path, TNP). • MR gets a new TNP at the new location • TNP is advertised by MR, to each MNN by sending a RA message.
ROB: Route Optimization Assisted by BGP (cont.) • The goal is • to enable mobile networks to seamlessly change their point of attachment to the Internet • while maintaining an efficient routing optimization between any pair of MNN and CN. • to reduce the number of signaling messages that could be generated, • to improve the quality of service in term of delays, • to preserve established sessions without deploying other additional entities, and • to solve the triangle or dog-leg routing problem
ROB – Location Registration Process • When a mobile network changes its point of attachment to the Internet, it first gets a topologically correct • CoA for its egress interface, • new TNP from the visited AR. • advertises the delegated prefix to its subnet by sending a RA • enables each mobile network node to build its CoA • The MR advertises this TNP to its home network’s border router, which will • update its BGP routing table and • send the updates to its border router peers. • according to the standard BGP’s behavior.
ROB – Communication Procedure • communication starts from a MNN • it sends packets using its CoA as source address. • communication process is initiated by any CN • receives the home address of the MNN by means of DNS request • sends its first packets toward the nearest border router (BR3) within its AS • be routed to the home AS using the home mobile network prefix (MNP) • assume that these first packets are tunneled by the home agent (HA) to the current location of mobile network, • e.g. using NEMO basic support protocol
the BR3 advertise the CN with the new location of the MNN, • By sending him the new TNP related to MNN’s new location. • CN forms the corresponding couple (MNN address-CoA) and sends the following packets using the CoA as destination address
a typical format of the update message used to advertise both BR and CN of the new location of the mobile network
Performance Analysis– Analytical Analysis [3, 5]ms 3 10 11
Performance Analysis– Simulation Analysis • Use OPNET Modeler • CBR, 200kbps, between CN and MNN (CN to MNN) • A background traffic is injected within the network
Conclusion • a route optimization scheme assisted by BGP is proposed for large scale? network mobility • improves quality of service in terms of bandwidth usage and end to end delays • few modifications in the BGP routing tables • TNP update message, CN operation • Analytical and simulation results show that ROB scheme outperforms the NEMO Basic Support scheme in terms of communication delays. • may incur a small control message overhead within the core network • Future work • investigate the impact of this control packet overhead • Nested network mobility
Comments • ROB scheme indeed achieves route optimization • topologically correct CoA • For IPv6 nodes • But handover delay… • Can established sessions really be preserved? • Their analytical analysis method is simple, but is acceptable in GLOBECOM • Reducing additional entity (function) helps when deploying • Tradeoff