What is Multiprotocol Label Switching (MPLS)?

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Multiprotocol Label Switching

Multiprotocol Label Switching (MPLS) is a routing system used in carrier backbones and enterprise networks to connect branch offices and enterprises with real-time applications that require quality of service (QoS). MPLS routes traffic using path labels rather than long network addresses instead of sophisticated lookups in a routing table like in IP networks.

MPLS is a multiprotocol overlay network protocol that can encapsulate other network protocols. As data enters the MPLS network, this packet switching mechanism divides it into packets with a header and a payload. MPLS routers use a label in the packet's header to steer it to its destination, where application software retrieves the payload and uses it.

How Does MPLS Work?

In an MPLS network, the ingress router, also known as the Label Edge Router, labels each packet as it enters the service provider's network (LER). This router also determines which LSP the packet will use to reach its destination address.

All subsequent label-switching routers (LSRs) forward packets only based on those MPLS labels; they never look at the IP header. Finally, the egress router removes the labels from the original IP packet and sends it on its way to its final destination.

Each packet has one or more labels, all stored in an MPLS header on top of all other headers attached to the packet. The FECs are indicated on the labels of each packet. Routers don't look at the packet's other headers and can ignore the IP header entirely. Instead, they look at the packet's label and send it to the appropriate LSP.

MPLS can work with nearly any protocol since MPLS-supporting routers need to view the MPLS labels attached to a packet (hence the name "multiprotocol"). It makes no difference how the rest of the packet is constructed as long as the router can read the initial MPLS labels.

Is an MPLS Network Considered "Private"?

MPLS can be "private" because some MPLS paths are only used by one enterprise. MPLS, on the other hand, does not encrypt traffic. It is possible to read packets if they are intercepted along the pathways. VPN can be used to encrypt the network connection and keep it private.

Where is MPLS Used?

This MPLS technology is typically utilized when a firm has numerous distant branch offices throughout the country or worldwide that require access to a data centre or applications at the organization's headquarters or another branch site.

Compared to typical IP routing, MPLS is scalable, provides higher performance and bandwidth, and improves user experience. However, it is expensive, difficult to distribute internationally, and lacks the flexibility to be carrier agnostic.

The old MPLS hub-and-spoke strategy has grown inefficient and costly as enterprises transfer their applications to the cloud; this is because −

  • It necessitates routing traffic through the organization's headquarters and out to the cloud rather than connecting directly to the cloud, substantially influencing performance.

  • The demand for bandwidth and cloud knowledge grows as firms add more apps, services, and mobile devices to their networks, increasing prices and operational complexity.

Advantages of MPLS

Following are some of the major advantages of using MPLS −

  • Service providers and corporations can utilize MPLS to implement QoS by designing LSPs that meet certain service-level agreements (SLAs) on traffic latency, jitter, packet loss, and downtime.

  • MPLS also allows for the establishment of virtual private networks (VPNs), virtual private LAN services, and virtual leased lines, as well as traffic separation.

  • One of the most apparent advantages of MPLS is that it is not restricted to any one protocol or mode of transport. These protocols can be used to establish an LSP; it supports transmission across IP, Ethernet, asynchronous transfer mode (ATM), and frame relay.

  • Beyond packet switching, Generalized MPLS (GMPLS) expands MPLS to manage time-division multiplexing (TDM), lambda switching, and other types of switching technologies.

Some of the other advantages of MPLS are as follows −

  • It is ideal for latency-sensitive real-time applications, including video, telephony, and mission-critical data.

  • On the same MPLS network, data and voice apps can coexist.

  • Different types of data can have different priority and service classes preprogramed.

  • Different percentages of an organization's bandwidth might be assigned to different categories of data.

Disadvantages of MPLS

Following are the disadvantages of using MPLS −

  • Expensive − MPLS is more expensive than traditional Internet access.

  • Long setup time − Setting up complex dedicated paths across one or more massive networks takes time.

  • Manual Configuration − The MPLS vendor or the business employing MPLS must manually configure LSPs. This makes it difficult for companies to expand their networks swiftly.

  • Non-Encryption − MPLS is not encrypted, so any attacker intercepting packets over MPLS lines can read them in plaintext. Encryption must be configured independently.

  • Cloud Dependent − Organizations that rely on cloud services may not establish direct network connections to their cloud servers because they lack access to the individual servers where their data and applications reside.

Updated on 14-Apr-2022 13:14:28