Performance analysis of IP datagram transmission delay in MPLS: impact of both the number and the bandwidth of LSPs of layer 2

LSR (label switching router)s in MPLS (multiprotocol label switching) networks map arriving IP flows into some labels on the layer 2 switching fabric and establish LSP (label switching path)s. By using LSPs, LSRs not only transmit IP datagrams fast with a cut-through mechanism, but also solve the traffic engineering issue to optimize the delay of some IP datagram flows. So far, we have analyzed the performance of LSR focusing only on the maximum number of LSPs which can be set on layer 2. We also consider the bandwidth allocated to each LSP and analyze the IP datagram transmission delay and the cut-through rate of LSR. We suppose the label mapping method as the data-driven scheme in the analytical model, so that the physical bandwidth of LSR is shared by both the default LSP for hop-by-hop transmission and the cut-through LSPs. Thus, we investigate the impact of the bandwidth allocation among these LSPs on the performance