The Study Of Survivability Technology In PTN

In order to effectively reorganize the existing network resource and industrial structure optimization, the conception of integration of three networks has been proposed, and becomes increasingly intense. The integration of three networks can be interpreted as the integration of services. It not only inherits the current voice, data and video services, but also includes other derivative value-added services, broadcast multi-services and new end to end band provider mode, such as video email, teletext, network telephone (Voice over IP) and network games. However, the services integration requires more for network's performance. Traditional Synchronous Digital Hierarchy (SDH), Ethernet and IP technology cannot satisfy the transport and carrier requirement of the next generation network. As optical transport network architecture, Packet Transport Network (PTN) can handle burst packet service, and satisfy the requirement of statistical multiplexing transport. PTN inserts a transition layer between IP layer and optimal transport media. The transition layer can support multiple services with the core packet service. At the same time, PTN also inherit the traditional advantage of optical transport, such as high availability and reliability, efficient bandwidth management and traffic engineering, convenient OAM, network management, scalability, and higher security, etc. With the wide range of applications of Wavelength Division Multiplexing (WDM) and photonic communication technology, effective bandwidth in a single fiber can reach 1 Tb/s. Such a tremendous bandwidth leads to more rigorous requirement of service continuity and data integrity. Survivability has been a key problem in network design and optimization. Therefore, the research of PTN survivability technology has a great significance.This paper makes an in-depth study of survivability in PTN, based on concluding the characteristics of PTN and the key technologies in PTN. The paper also expounds the survivability requirement in PTN and introduces the existing survivability technologies in PTN. Moreover, the merit and fault of each solution is analyzed.After the systematic investigation of the survivability technologies in PTN, the conception of Shared Risk Link Groups (SRLG) proposed recently emerged. Although the working path and the backup path that can satisfy the SRLG constraint can share resources, it cause "Trap" problem. Against this problem, this paper proposes a novel Dynamic Shared Segment Protection (DSSP) algorithm, and makes detailed comparison with the share link protection (SLP) and the Uniform Non-overlapping Segmentation algorithm (UNS). Simulation results show that the proposed method has better performance in average bandwidth utilization, links occupied by the backup path and the probability of "trap".In addition, with the consideration of operability, this paper proposed a segment protection method based on Resource Reservation Protocol-Traffic Engineering (RSVP-TE) for MPLS-TP network which is a typical technology of Packet transport network.