What is MPLS?
Multi Protocol Label Switching (MPLS) is an IETF (Internet Engineering Task Force) government-approved wide area networking standard created to:
MPLS is available in three types:
MPLS Layer 2 Point to Point
Layer 2 point-to-point is a cost-effective way and a flexible alternative to high bandwidth leased lines. Many wholesale network operators have based their core network infrastructure on ethernet and use Layer 2. This type of transport is protocol-agnostic and allows anything running over the LAN to be sent over the WAN without having to use routers to convert packets up to Layer 3, the network layer.
MPLS Layer 2 Virtual Private LAN Services (VPLS)
Virtual Private LAN services are growing in popularity for delivering ethernet services. They combine MPLS and ethernet, allowing both customers and carriers to benefit. For over two decades, ethernet switching has dominated the local area network, while IP routing has dominated the carrier network. IP backbones have been used to provide Internet access and, more recently, to provide IP VPN access. Corporate VPN services have been typically provided with existing TDM, ATM and Frame Relay Networks. During this period, Ethernet has continued to scale the bandwidth spectrum and with its simplicity and cost-effectiveness, it has established itself as the infrastructure of choice in the metro and the WAN.
Otherwise known as transparent ethernet services, VPLS is a newer protocol that works over MPLS and gives customers a combination of the benefits of the two above network types, i.e. the ability to operate a multipoint network AND pass all traffic at Layer 2 over the WAN. Due to its simplicity, robustness and ability to scale traffic to 10 Gbps.
Advantages of Layer 2
Disadvantages of Layer 2
MPLS Layer 3 IP/VPN
Particularly suitable for vast, multi-site enterprises, i.e. retail chains, that deploy a large number of low bandwidth sites or large corporates with offices deployed globally. This type of service is a natural progression away from legacy frame relay and ATM services.
Advantages of MPLS Layer 3 IP/VPN
Disadvantages of MPLS Layer 3 IP/VPN
In summary, both Layer 2 and Layer 3 services have their advantages and disadvantages. The solution that needs to be provided is dependent on what access you will choose. GCOMM recommends Layer 3 MPLS due to its ability to scale and provide monitoring for troubleshooting.♦ End