1 Route Optimization for Large Scale Network Mobility Assisted by BGP Feriel Mimoune, Farid Nait-Abdesselam, Tarik Taleb and Kazuo Hashimoto GLOBECOM 2007

2 Outline Introduction Related Work ROB: Route Optimization Assisted By BGP Performance Analysis Conclusion

3 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).

4 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

5 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.

6 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

7 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.

8 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

9 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.

10 of MR

11 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

12 –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

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14 a typical format of the update message used to advertise both BR and CN of the new location of the mobile network

15 Performance Analysis – Analytical Analysis [3, 5]ms

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17 Performance Analysis – Simulation Analysis Use OPNET Modeler –CBR, 200kbps, between CN and MNN (CN to MNN) –A background traffic is injected within the network

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19 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

20 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