Special Issue Article
A Comparative Study on Protection Methods in MPLS-TP Networks
Today the data traffic is growing more than ten times the rate of voice traffic. Time Division Multiplexing (TDM) based technologies has been for a long time a major player for data transport, it shows weakness on busty traffic such as packetized voice and video especially because of the fast growth of the demand for service sophistication and expansion. Carriers need to migrate from TDM to packet in order to meet packet transport network (PTN) requirements and to make efforts to minimize the cost for providing these services. Traffic Engineered Provider Backbone Bridging (PBBTE) is a new technology concept that promises to provide a true Carrier grade Ethernet transport network solution. A Joint Working Team created by International Telecommunication Union-Telecommunication Standardization Sector (ITU-T) and Internet Engineering Task Force (IETF) is actually developing a new packet transport technology namely, Multi- Protocol Label Switching-Transport Profile (MPLS-TP) taking benefits from existing MPLS networking infrastructure. As per MPLS-TP requirements, protection and resiliency are the key features for packet transport networks. The traditional protection mechanism in MPLS-TP can provide various protection methods, e.g. the 1+1, the 1:1,the m: n, and the ring protection. The concept of shared risk link groups (SRLG) has been proposed and widely used in the calculation of protection path. The active fault-alarm technology (AFA) has great potential for a more efficient and dynamic protection mechanism in the future high-speed transport network. The active dynamic pre-protection (ADPP) mechanism combines together both advantages of the 1:1 protection mechanism and the restoration approach. A comparative study on traditional and novel protection mechanism used in MPLS-TP gives an effective idea about the protection schemes and further modifications.