Multi Protocol Label Switching is an emerging technology used for fast transmission of data and avoid congestion. This book focusses on MPLS complete study of its working and different types of VPNs that can be implemented. This book also focusses on other protocols which run at the backbone and their implementation and working in details for better understanding. Multi protocol label switching works on the labels and these labels can be used to find path for the packets within the networks. There are different planes which are used to find the path for the routers. Thus enable router to find the path in an efficient manner than traditional routing protocol.