Access nodes in NGN are likely to transport voice traffic using MPLS Traffic Trunks. The traffic parameters describing a Traffic Trunk are basic to calculate the network resources to be allocated along the nodes belonging to its corresponding Label-Switched-Path (LSP).
This paper provides an analytical model to estimate the lower limit of the bandwidth that needs to be allocated to a TT loaded with a heterogeneous set of voice connections. Our model considers the effect of the Silence Insertion Descriptor (SID) frames that a number of VoIP codecs currently use. Additionally, two transport schemes are considered: VoIP and VoMPLS. The results, experimentally validated, quantify the benefits of VoMPLS over VoIP.