MPLS Tutorial

MPLS tutorial is a simple tutorial for MPLS, DiffServ and MPLS over DiffServ.It also deals with SNMP and how to set up linux MPLS routers at lab. We have also dealt with linux filters and linux queuing disciplines. .If you are looking to buy a MPLS book, I would strongly recommend. MPLS: Technology and Applications (Morgan Kaufmann Series in Networking)

What is MPLS and It’s Benefits

Before MPLS basics functionality is explained, the following three drawbacks of traditional IP routing need to be highlighted:

  • Routing protocols are used on all devices to distribute routing information.
  • Regardless of the routing protocol, routers always forward packets based on the destination address only. The only exception is policy-based routing (PBR), which bypasses the destination-based routing lookup.
  • Routing lookups process is performed on each router which means that how a router will find the exit interface for an IP network. Each router in the network makes an independent decision when forwarding packets. MPLS helps reduce the number of routing lookups and can change the forwarding criteria. This capability eliminates the need to run a particular routing protocol on all the devices.
MPLS Definition

MPLS is a famous networking technology that uses labels which are attached to packets to forward them through the network. MPLS is standard from IETF for including routing information in the packets of an IP networks. MPLS is used to ensure that all packets in particular flow take the same route over a backbone. MPLS can deliver the quality of service  (QOS) required to support real time voice and video as well as service level agreements (SLAs) that guarantees bandwidth. In computer networking and telecommunications is data carrying mechanism related to packet switched networks. MPLS operates between that OSI layer 2 and the layer 3, so it can be considered as layer 2.5 protocol. It can be used to carry many different types of traffics including IP packets, ATM, SONET and ETHERNET frames.

Multi Protocol Label Switching is a technology for delivering IP services. MPLS technology switches packet (IP packets, AAL5 frames) instead of routing packets to transport the data. MPLS packets can run on other Layer 2 technologies such as ATM, Frame Relay, PPP, POS, and Ethernet. Other Layer 2 technologies can be run over an MPLS network.

Multiprotocol Label Switching (MPLS) is a protocol framework used to prioritize Internet traffic and improve bandwidth utilization. Those functions are accomplished by inserting a label between OSI layer 2 and OSI layer 3 in a packet and forwarding the packet based on the label contents alone as in ATM networks. Performance and efficiency are increased by this approach because less time is required to process a label than to process routing information like source and destination IP addresses. Errors are also detected more quickly they can only occur with a single label than with potentially several data types in different protocols. Figure describes a packet that has been modified for MPLS. Protocol data which is above layer 3 is unused in MPLS while layer 2 data appears transparent. Since the Internet is a collection of numerous networks using various communications technologies MPLS can be used without any changes to those existing mechanisms.

MPLS Tutorial

Benefits of MPLS:

Multiprotocol Label Switching (MPLS) is a versatile solution to address the problems faced by present day networks.  Some of the benefits are given below.

  • Speed
  • Scalability
  • QOS (Quality of Service) management
  • Traffic Engineering 

MPLS has emerged as an elegant solution to meet the bandwidth-management and service requirements for next generation Internet Protocol (IP) based backbone networks. MPLS addresses issues related to scalability and routing (based on QoS and service quality metrics and can exist over existing Asynchronous Transfer mode (ATM) and Frame Relay networks.

* What is MPLS?- What is MPLS (Multi Protocol Label Switching)?
* MPLS Basics– Explains MPLS (Multi Protocol Label Switching) Basics?
* MPLS Labels
* MPLS TE – This topic explains MPLS Traffic Engineering (TE), gives its introduction and objectives.
* Choice of signalling protocol : RSVP-TE
* Differentiated Services or DiffServ
* DiffServ over MPLS: Introduction and Benefits
* Simple Network Management Protocol (SNMP), MIBs and SMI
* Linux Filters and Queuing Discipline
* How to implement filter on Linux machine using TC scripts for MPLS?
* How to Set DiffServ over MPLS Test-Bed on Linux Routers?
* How to compile linux to create a DiffServ over MPLS router in lab?

I am also on creating mpls tutorial in pdf format for the readers that I believe would be helpful. MPLS Tutorial (PDF format) would be available soon.