The Design And Implementation Of Embedded Mobile IPv6 Protocol Stack

With the development of next generation network technology, more and more embedded devices enter the internet and they require more IP addresses and good mobility.IPv4 protocol only has a 32-bit address space and it has many disadvantages in mobility, so it can't meet the requirement that embedded devices need. As the standard network protocol in NGN, IPv6 protocol will replace IPv4 and become the new mainstream. IPv6 has many advantages, such as 128-bit address spaces;address auto-configuration;good support for mobility and security authorization mechanism, so it can meet the needs of embedded devices in NGN. In order to ensure embedded devices to communicate continuously, when they move around in different IPv6 subnets, the implementation of mobile IPv6 protocol is very necessary.This paper analyzes the mobile IPv6(MIPv6 for short) protocol in details, studies design methods of embedded protocol stack, proposes a design model which is modularized, single process and multithreads.running mode. The system refers to current open source project lwip and MIPL project, and implements mobile IPv6 protocol stack, also designs operating system emulation layer to implement portability. The paper divides three big modules according to three functionality entities (mobile node, home agent, correspondent node), and many sub-modules combing to specific functions. All the sub-modules run as different threads and communicate with each other through threads synchronization mechanism.Three functionality entities belong to different running environments, so the MIPv6 stack provides customized functionality interface to users, then users can run the proper entity as their needs.The whole design of MIPv6 stack accords with specification of mobile ipv6, and has the characteristics of small code and covering little memory when running, so it meets the performance requirement of embedded devices. This protocol stack also has good portability and extension ability. All the modules has been implemented and testified.