I am investigating why we, as an enterprise, should move toward MPLS. What benefit does it give you? Anyone implements MPLS (not buying MPLS service) on their network and do you notice any difference? Do you gain any more speed? Are you able to control traffic better than tuning/redesigning IGP? Why QoS on MPLS is better? Please let me know. Thank you!
There are a few applications of MPLS for enterprise that may or may not have value for you.
1) VPN support. A la RFC2547, you may, as dvr0 suggested, segregate L3 information including address space, routing policy, reachability, etc. For example, you may have a subsidiary or acquisition that you provide transport for, but you want to keep separate in all other ways. However, you want to save costs by not buying additional hardware or circuits to support their traffic. MPLS L3VPN can be leveraged.
2) Layer 2 tunneling. Though there are several ways to accomplish this, you may want to extend the VPN concept by interconnecting and/or interworking layer 2 devices like LAN or ATM Switches, HDLC or Frame-relay, etc., across your existing infrastructure, without impacting other users and without buying dedicated circuits. AToM is one approach to accomplish this.
3) Traffic engineering. Suppose you want to take advantage of unused bandwidth, or determine the network path based on bandwidth, custom cost, or custom attributes such as time of day, affinity, traffic type, Int Serv signalling, etc,. The path chosen can be either dynamic or deterministic. And the solution needs to be scalable, manageable, and converge extremely quickly. MPLS Traffic Engineering is an approach that meets these requirements.
These are some of the most popular applications of MPLS and are all useful for and being adopted by enterprises.