978-1-4244-4547-9/09/$26.00 ©2009 IEEE TENCON 2009 Optimizing the MPLS Support for Real Time IPv6-Flows using MPLS-PHS Approach Imad J. Mohamad National Advanced IPv6 (NAv6) Universiti Sains Malaysia (USM) Penang, Malaysia imad@nav6.org Tat-Chee Wan, Faisal Y. ALzyoud, Putra Sumari School of Computer Sciences Universiti Sains Malaysia (USM) Penang, Malaysia tcwan@cs.usm.my , faisal@nav6.org , putras@cs.usm.my Abstract—The huge coverage space of IPv6 addresses and providing guaranteed support for the ever increasing customer demand, results in the dealing with bigger packet header-size compared to the payload-size especially in some real time video and audio applications, consequently more bandwidth is wasting. Using the advantages of MPLS with IPv6 is still one of the migration challenges at the backbone. Payload Header Suppression (PHS) approach is currently being used in Mobile WiMAX networks for point to point (SS to BS) communications. The proposed approach for this paper (named) MPLS-PHS adapt the concept of the PHS technique mentioned above, modified to be applicable for multihop of Label Switching Path (LSP) of MPLS domain at which multipoint-to-multipoint connection found (Ingresses to Egresses).The results clearly show a dramatic increase in the data throughput for real time IPv6 flows. Keywords-component; MPLS, QoS, IPv6, Real Time Applications and Traffic Engineering I. INTRODUCTION Suppression and Compression are two closely related techniques, which deal with packet header reduction. PHS and Robust Header Compression (RoHC) are two well known approaches used for header reduction in wireless and satellite environment, targeting utilization of their limited and costly bandwidth. This utilization is not free; most available approaches require extra processing time and extra memory space (software and/or hardware solutions) to accomplish this task. Typically VoIP (as an example) uses the encapsulation voice/RTP/UDP/IP. When MPLS labels are added, this becomes voice/RTP/UDP/IP/MPLS-label. Also MPLS VPNs use label stacking, and in the simplest case of IPv4 the total packet header at least 48 bytes, while the voice payload is often no more than 30 bytes. When IPv6 used, the relative size of the header in comparison to the payload is even greater [1]. This paper focuses on UDP flows of real time applications. It is organized as follows: Section II covers the essential backgrounds. Related work is discussed in section III. The developed methodology is discussed in section IV. Scenarios and Simulation results explained in section V. Conclusion outlines stated in section VI. II. BACKGROUNDS A. MPLS fundamental Ingress and Egress are the input and output doors of the MPLS cloud (Fig. 1), where labels are pushed at the former and popped at the later. The LSR (Label Switching Router) located one hop before the Egress is called Penultimate. The Penultimate pops the label instead of Egress, when this facility is activated. Core LSRs forwards the labeled packets without considering on their layer 3 IP headers, behaving as Transit routers. The 32 bits MPLS header is located between MAC header and IP header as shown in Fig. 2. At the core of MPLS cloud, routing is done by 20 bits MPLS-label instead of 128 bits (IPv6) of layer 3. Label Distribution Protocol (LDP) was designed for distribution of labels inside MPLS domain. One of the most important services that may be offered using MPLS in general and LDP in particular is the support of constraint-based routing of traffic across the routed network. Figure 1. MPLS domain. Figure 2. MPLS shim header structure. Label (20 bits) EXP (Traffic Class) (3bits) Stack (1bit) TTL (8bits) MAC Header MPLS Header IP header Payload 32 Bits 1