An SCTP Based Decentralized Mobility Framework

Abstract: IP address has become a key feature in the current internet architecture. However, the basic design of Internet Protocol stack is based on architecture shaped years ago, when internet was a static network. Fixed IP addresses did not cause any problems until communication devices became mobile, because when a Mobile Node (MN) in an active association with another node, changes its Point of Attachment (PoA) its current IP address changes and hence its active session terminates. Different techniques are implemented to support mobility using Internet Protocol Stack. Mobile IP supports mobility at network layer, mSCTP supports mobility at transport layer, and SIP works at application layer. Although the question, that which layer is suitable for mobility is still an open issue. Stream Control Transmission Protocols (SCTP) exploits its multihoming feature along with Dynamic Address Reconfiguration (DAR), to provide a non-delayed handover solution with higher security and almost negligible packet losses. However, mSCTP requires location management to provide a complete and reliable handover solution. Location management in IP based handovers provides an IP address of the MN. This requirement can be fulfilled by using Chord, which along with DHT can provide the required name to IP mapping. Chord is DHT lookup algorithm, which can efficiently retrieve the key-value pair by mapping the key onto a node that contains the required value. We propose a decentralized mobility framework for IP based handovers that does not involve any evolutionary technology changes for its deployment. Suitability of our framework is tested by preliminary analysis of Chord look-up efficiency and SCTP handover procedure. Our mobility framework exploits the multihoming feature of SCTP to provide handoff management and efficient key-value mapping of DHT Chord to provide the necessary location management. Efficient look-up algorithm, high scalability, flexible naming, authorization support, and no central point of failure make DHT Chord an ideal candidate for location management. Backed by mSCTP multihoming feature and DAR extension, Chord can efficiently provide the required location information and support non-delayed handover procedures. Besides technical advantages, end users will gain added functionalities and more flexibility from this mobility framework.