International Journal of Future Generation Communication and Networking Vol.6, No.5 (2013), pp.81-96 http://dx.doi.org/10.14257/ijfgcn.2013.6.5.09 ISSN: 2233-7857 IJFGCN Copyright ⓒ 2013 SERSC IP Backbone Security: MPLS VPN Technology Abid Shahzad 1 and Mureed Hussain 2 Faculty of Computing, Shaheed Zulfikar Ali Bhutto Institute of Science and Technology (SZABIST), H-8/4, Islamabad 44000, Pakistan. a4abishah@gmail.com 1 , mhussain@szabist-isb.edu.pk 2 Abstract The Multiprotocol Label Switching (MPLS) technology is currently the most deployed technology by service providers over backbone networks. The highly useful MPLS application nowadays is the MPLS Virtual Private Network (VPN). Due to the enterprises and organizations demand of allowing the remote sites and users to connect to enterprise network, MPLS VPNs have become more attractive. The service providers are using MPLS VPN technology to provide the end users a secure channel across the public internet, with flexibility and scalability. MPLS VPNs have the functionality to operate over both MPLS networks as well as existing IP networks. Variety of research has been conducted in this area and many researchers have proposed different models and solutions to implement MPLS VPN technology more effectively and efficiently. This paper presents the detail analysis of the existing and future techniques and models which are used to implement, optimize, secure MPLS VPN technology. Keywords: MPLS, VPN, TE, QoS, LSP, BGP, PE, CE 1. Introduction Multiprotocol Label Switching (MPLS) was introduced by IETF [1]. It is a tunneling technology, which gives the platform to create and implement MPLS based Virtual Private Networks (VPNs). It is developed to enhance the packet forwarding over the high performance backbone networks. MPLS forwards the IP packets to the distinct routers instead of the end devices on the basis of small labels [2]. The MPLS application helps to create a tunnel or Label Switched Path (LSP). The small labels are sent over the path. The ingress (entry point of MPLS network) router over the MPLS network path appends this small label to the arriving packet. Over LSP, the hops swap the labels with the new ones to forward the packet. This process keeps on going until the packet arrives at the egress (exit point of MPLS network) router. The egress router strips-off the label and sends the packet towards its destination [3]. The basic advantage of MPLS technology which we just noticed is that IP header analysis which on the other hand is necessary in traditional IP packet forwarding mechanism does not need here. The IP header is analyzed and a small label is appended to the packet at the entry point of the MPLS network. The ingress router may also analyze some extra information about the entering packet to assign it the best route which results in achieving the Quality of Service (QoS). When we talk about the traffic engineering as compared to traditional IP networks, it becomes so easier after choosing the explicit routes in MPLS network. So, this makes the MPLS technology more efficient. The demand of securely sharing confidential data over public networks is growing day by day as the organizations are expanding their networks. The data sharing between offices, sub offices, and end users is an important requirement of large organizations and ensuring data