IDRM: Inter-Domain Routing Protocol

for Mobile Ad Hoc Networks

C.-K. Chau, J. Crowcroft, K.-W. Lee, S. H.Y. Wong

Mobile Ad Hoc Networks (MANET)

Do not depend on infrastructural support A MANET is a mobile, multi-hop wireless network which

is capable of autonomous operation.Easy to set up (possibly) a short-lived network for a

collection of nodes.

Characteristics– Energy constrained nodes– Bandwidth constrained– Variable capacity wireless links– Dynamic topology

Motivation

BGP – Broader Gateway Protocol For inter-domain routing in Internet. Allows Autonomous Systems to communicate with

each other. Opaque Interoperation.

GOAL- A BGP like solution for inter-domain routing for MANETs

Challenges in MANET Dynamic Topology Changes Newer MANET protocols

BGP- Broader Gateway Protocol Why BGP fails in MANETs ?

Path vector protocol Assumptions- Internal Gateway Detection Internal Network Knowledge The above assumptions do not hold true for MANETs

using reactive/hybrid routing protocols. IP prefix aggregation

BGP Aggregates IP addresses in the domain by IP prefixes (e.g., 92.168.0.0/16).

Creation of arbitrary network partitions and merges in MANETs

IP prefixes may not suitably aggregate the IP addresses in partitioned MANETs.

Existing Solutions

Loop detection in Path vector protocol Filters path that contain repeated AS numbers. May fail in MANETs.

Existing Solutions

Plutarch and Turfnet focus on high level architecture rather than provide

a practical solution to the problem

SHARP uses hybrid routing protocols

Cluster-based networking Self organizing clusters Routing backbone among cluster heads

Focuses on single-domain

Existing Solutions

Modelled on BGP Main Feature – Opaque Interoperation

Allows heterogeneous intra-domain routing protocols

Allows heterogeneous inter-domain routing policies

Key Design Points Handling Domain level Topology changes

How to discover partitions and merges? IDRM proposes periodic internal gateway

detection Proactive routing domain- partitions discovered

using route updates Reactive routing domain- Maintain soft state by

sending beacons periodically. Generate new MANET ID on partition discovery

IDRM

Computation of MANET ID Goal is for each gateway to generate the ID and that

the collision of IDs is low. Generate random ID using pseudo random

generator with the IDs of all the gateways as input Prefix it by the domain ID to generate a new

MANET ID Why prefix domain ID ?

Merging of network partitions

The dynamic allocation of MANET ID prevents the path vector protocol from detecting a false loop.

IDRM

Membership Management and Announcement Gateway nodes collect the IDs of all the nodes in

the MANET for advertisement to other domains Membership Digest

Contains node ID information(IP address) Non-gateway membership Proactive routing domain- membership

information is available through the update messages

Reactive routing domain- initiate membership query

Policy Support Encoding of the domain ID in MANET ID

IDRM

Data Plane Operations A node sends packet to one of the reachable intra-

domain gateway A route discovery is initiated in the case of reactive

domain to find the gateway node which has the route to the destination

Once the packet reaches the intra-domain gateway, it checks to see if it is directly connected to the destination, if it is connected it forwards the packet to the destination.

If not, the packet is forwarded to the gateway which has the route to the destination

IDRM

IDRM- Illustration

Domain Policies A is willing to provide transit service for B, but not

for C, B,C are willing to provide transit service for others.

IDRM- Illustration

IDRM- Illustration

IDRM- Illustration A1 wants to send packets to a0 Proactive(OLSR)- Based on Link state information a1 know that

both the destination a0 and default gateway a3 are disconnected from the MANET.

Reactive(DSR) – initiate route discovery, a2 responds Forward packet to reachable gateway a2 A2 forwards the packet to b2

Performance Evaluation

Proactive Intra-Domain Routing Protocol

= # of hello packets/sec Reactive Intra-Domain Routing Protocol

= beaconing rate between pair of gateways = avg 3 of hops between a pair of nodes

Inter Domain Routing Protocol

Overhead Analysis

= Connectivity breakage rate of connected pairs of intra-domain gateways

Overhead Analysis

Limitations

Scalability BGP – Scalable IDRM – not scalable

Isolation of nodes Special Hardware requirements

Multiple radio channels Different technology Gateway nodes require special hardware

Computation Overhead MANET ID computation

Limitations

Not Stateless Security Issues

The route updates are not secured distribution of IDs of all the nodes and gateways

within its own domain requires special mechanism to discover the

node IDs and then pass on this information to other nodes

Conclusion

IDRM offers a means for heterogeneous MANETs to interoperate

Identified challenges of inter-domain routing in MANETs

Established feasibility of opaque interoperation in IDRM

IDRM retains the merits of BGP Future research direction

References C.-K. Chau, J. Crowcroft, K.-W. Lee, S. H.Y. Wong, IDRM:Inter-domain

Routing Protocol for Mobile Ad Hoc Networks.Computer Lab, University of Cambridge. Technical Report UCAM-CL-TR-708

Y. Rekhter and T. Li. RFC 1771: a Border Gateway Protocol 4 (BGP-4), March 1995.

J. Crowcroft et. al.. Plutarch: an argument for network pluralism. ACM Computer Communication Review, 33(4):258–266, 2003.

S. Schmid et al. TurfNet: An architecture for dynamically composable networks. In Proc. of WAC 2004, October 2004.

Y. Chen, A. Liestman, J. Liu. Clustering algorithms for ad hoc wireless networks. In Proc. Ad Hoc and Sensor Networks ’04

V. Ramasubramanian, Z. J. Haas, and E. G. Sirer. SHARP: A hybrid adaptive routing protocol for mobile ad hoc networks.In Proc. ACM MOBIHOC, June 2003.