Understand the difference between MPLS and VPLS networks

MPLS and VPLS networks are important telecommunication elements. They are also known as Multiprotocol Label Switching and Virtual Private LAN (Local Area Network) service. They help transmit and translate IP (Internet Protocol) data to the user.

Multiprotocol label switching is part of the family of packet-switched networks in high-performance systems. It allows data to be forwarded based on its labels, without the need to parse the packet data. This eliminates reliance on data link layer (DLL) technologies, including Ethernet, Frame Relay, SONET (synchronous optical networks), and ATM (asynchronous transfer mode). This system is very scalable and highly efficient.

Multiprotocol label switching has made cell switching and signaling protocol obsolete. These elements were necessary in ATM networks. However, modern fiber optic data transfer speeds can reach 40 Gbit/s (Gigabits per second). That means that even full size data packets (1500 bytes) are no longer subject to real time delays. Since ATM cells were developed to help reduce real-time delays for large packages, new technology has made them relatively obsolete.

The out-of-band control and traffic engineering elements of ATM and frame relay have been retained in MPLS. Among the benefits of traffic management are increased performance and increased reliability. However, IT (Internet Technology) departments have less access to the multi-protocol label switching cloud.

This system works by adding header prefixes to packets. These headers contain labels, called label stacks. Within each stack of labels, there are four components. These include a 20-bit tag value and a 3-bit traffic class field for Explicit Congestion Notification (ECN) and Quality of Service (QoS). In addition, each stack of labels includes a 1-bit bottom-of-stack flag to indicate that it is the last label in the group and an 8-bit time-to-live (TTL) field.

The Virtual Private LAN service establishes Ethernet-based communications between multiple points on an IP or MPLS network. It effectively emulates a LAN. It uses pseudowires to provide the ability for geographically separated points to share a transmission domain on Ethernet. It is not restricted to point-to-point tunnels. Rather, this technology enables multi-point (any-to-any) connectivity.

This connectivity is achieved through the following method. At each site, the LAN extends to the edge of the provider’s network. The provider’s network then emulates a bridge or switch that connects all of the customer’s LANs. This creates a single bridged LAN.

Since a LAN is emulated with this system, full mesh connectivity is required. A mesh is a wireless communications network made up of radio nodes. Small nodes (repeaters) connect to large nodes or routers to increase coverage range. This system is redundant and reliable. If one node does not communicate, the other nodes are not affected. They can continue to function.

VPLS uses two methods to establish mesh connectivity. They include Border Gateway Protocol (BGP) and Label Distribution Protocol (LDP). Signaling is the process of establishing pseudo-wires. Auto discovery is the process of finding other PE routers on the same network. BGP allows for both automatic discovery and signaling. However, with LDP, individual PE routers must be configured.

MPLS and VPLS networks are technologically advanced systems that facilitate reliable, accurate, and fast data transfer. These networks can span large geographic regions.