MPLS ve GMPLS ağlarında restorasyonlu trafik mühendisliği ve rejeneratör konumlandırılması

ABSTRACT TRAFFIC ENGINEERING AND REGENERATOR PLACEMENT IN MPLS AND GMPLS NETWORKS WITH RESTORATION Emre Yetginer M.S. in Electrical and Electronics Engineering Supervisor: Assist. Prof. Dr. Ezhan Karaşan January 2002 Label switching technologies, standardized under the name Multiprotocol Label Switching (MPLS), provide performance advantages for core networks. MPLS enables traffic engineering and QoS support on conventional IP networks. Since MPLS uses the common control plane of IP protocol, it simplifies network man agement and decreases maintenance costs. Generalization of MPLS, called GM PLS, is seen as an important step in the evolution of architectures of optical transport networks. In this thesis, we discuss the problem of traffic engineering of restorable paths in MPLS networks and study four working and restoration path design methods. Each method is formulated as an Integer Linear Program ming (ILP) model, and relative performances of these methods are compared based on a proposed traffic uncertainty model. For optical networks, we study the traffic engineering problem taking into ac count the physical layer impairments and optical layer constraints. These factors limit the range of optical signals and necessitate placement of signal regenerators. This, in turn, affects the path selection process for each demand. We present an ILP formulation for the regenerator placement problem with the objective of SUSS] CSBJW&Musing minimum number of regenerators. Since the resulting formulation has a huge size making it impractical for large networks, we also develop two heuristic algorithms for the same problem. We compare the efficiencies of these algorithms in terms of the number of regeneration points needed. For the design of working and restoration paths in GMPLS networks, we develop an ILP formulation for path set creation which considers optical layer constraints and locations of re generators. We use traffic engineering models to demonstrate the effect of these algorithms on network performance. As in the MPLS case, performances of traf fic engineering methods are compared for the optical network using the traffic uncertainty modeling. Keywords: MPLS, GMPLS, traffic engineering, restoration, regenerator place ment, working and restoration path design IV