MPLS in the SDN Era

Chapter 16. Scaling MPLS Transport and Seamless MPLS

Today, our industry is experiencing a paradigm shift in service provider (SP) networking: network applications are becoming independent from the transport layers. Modern, cloud-based SP applications need flexible, intelligent overlay network services and are not well-served by legacy, static, low-layer data transmission.

This trend is driven by many factors:

• Increased demand to bring the service delivery point closer to the user. IP devices are progressively replacing legacy Layer 2 (L2) network elements, hence partitioning the L2 domains.

• More “intelligent” features for fast protection available at the IP/MPLS layer that could replace the corresponding fast protection features of optical networks.

• Shifting of mobile traffic—traditionally delivered over TDM circuits—toward Ethernet, and subsequently toward IP in 3G (e.g., Universal Mobile Telecommunications System [UMTS]), or 4G (e.g., Long-Term Evolution [LTE]), or small-cells networks.

• High-scale data centers shifting to MPLS fabrics and MPLS-enabled servers.

To cope with this demand, increasing the capacity of existing core (or spine) devices is necessary but not sufficient. The required presence of service endpoints in many small-range sites also relies on increasing the overall number of MPLS-enabled devices in the networks.

As a result of bringing the L3 edge closer to the end user, networks are witnessing the introduction of many small devices:

• In the edge ...