MPLS-Enabled Applications: Emerging Developments and New Technologies

15.2. NETWORK CONVERGENCE

A driving force for MPLS becoming the prevalent network technology in the future is network convergence, with many service providers beginning to consolidate disparate 'stovepipe' networks on to a single one based on MPLS. The endpoint for this convergence is for an MPLS network to carry all of a service provider's traffic, including PSTN and mobile voice traffic, Layer 2 data, Layer 3 VPN, Internet and broadcast television. Although at the time of writing there are few, if any, fully converged networks carrying all of these services, several service providers have programs underway to build such networks.

Let us review the reasons why MPLS has made possible the deployment of critical services that IP-based networks were previously regarded as not capable of supporting:

• Flexibility with respect to connectivity. An issue with native IP networks is that it is not possible to achieve end-to-end (PE-to-PE) bandwidth guarantees. MPLS achieves end-to-end bandwidth guarantees through traffic engineering and admission control, on a per-class basis if required. This 'connection-oriented' approach is highly desirable to meet the QoS requirements of traffic such as PSTN voice, broadcast video and some Layer 2 services, e.g. those that emulate or replace ATM CBR services. On the other hand, other classes of traffic can be handled without any bandwidth guarantees (or can be allowed to oversubscribe their bandwidth reservation) in order to make use of statistical multiplexing. ...