The Design And Implementation Of Signaling Protocol CR-LDP For MPLS

With the rapid development of information technologies, large numbers of new technologies are proposed and implemented which extend the abilities of current network whereas require dimensions and bandwidth enhancement of network. To solve the problem that lack of network capabilities suffocates the evolution of network service, MPLS is proposed as a kind of transmission & switching technology, which has lower limitation of evolution and supports higher bandwidth. In possession of favorable support of QoS and traffic engineering, MPLS is utilized and expanded in various areas, such as VPN increment service field, wireless network, optical network, mobile network, etc. As a critical part of MPLS technology, signaling protocol takes the responsibility to establish a data transmission path during adjacent LSRs in MPLS network. CR-LDP, which is a separate control protocol of MPLS, is the signal protocol supporting traffic engineering especially proposed by IETF for MPLS network. In this thesis, the foreground and main signaling protocols of MPLS technology are discussed firstly, and then the characteristics of conception and component of CR-LDP protocol are described in detail. Besides, the CR-LDP and RSVP-TE signaling protocols are compared and analyzed in many aspects. The thesis focuses on the design and implementation of CR-LDP protocol stack. After the analysis of partition and relationship of function modules in MPLS, a software architecture based on divided module structure is presented for CR-LDP signaling protocol stack with excellent support in portability and extensibility. Besides, this CR-LDP signaling protocol stack has been implemented in VxWorks real-time embedded operation system. The functions of these modules that constitute the protocol stack are illustrated and depicted at length; and the key flow charts and design methods are also analyzed particularly. Further, a test scheme is designed to validate the capability and performance of the protocol stack. The results of test cases at different scenarios indicate that the CR-LDP protocol stack achieves the label distribution requirement. The CR-LDP protocol stack has been launched into the research project of MPLS technology. And the architecture of this protocol stack has been inherited to devise the signaling protocol of GMPLS network, which demonstrate the excellent extensibility and practicability of our CR-LDP protocol stack.