Why we choose mpls over point to point only because it is cheap

Question

I need a document explaining the advantages and disadvantages of converting point to point connectivity to MPLS and the plan / suggestion to overcome the disadvantages

Answer 1

Hi,
Converting a network that consists of point-to-point links to run MPLS can have benefits. This is regardless of the type of links you have in the network.
One starting point could be this one:
http://en.wikipedia.org/wiki/Multiprotocol_Label_Switching
The big benefit that comes with deploying MPLS in your network is the ability to run the MPLS applications. Here are the most important ones:
-MPLS VPN - Layer 3 (with multicast)
-MPLS VPN - Layer 2 - point-to-point or point-to-multipoint
-MPLS Traffic Engineering - point-to-point or point-to-multipoint
Each of these have their benefits, while running over a one common network : an IP network with MPLS enabled.
The most important benefits are:
L3 VPN : obviously gives you seperated VPNs, with the possibility of overlapping IP subnets
              extreme easy provisioning of layer 3 VPNs
L2 VPN: supports transporting most supported layer 2 protocols, even protocols with clocking information
MPLS TE: steering of traffic through the network and extremely fast traffic protection
These are just the most important ones.
All of these applications run on one common network, while before MPLS, one needed to have multiple carrying networks (e.g. one Frame-Relay network, one ATM network, one IP network) in order to provide all the same functionality.
Regards,
Luc