Most of the operators are using circuit switched technology as transport network. But most of the services are packet based services, so why not to use packet based networks to offer high bandwidth packet based services. The need of high bandwidth hungry application demands to upgrade the infrastructure. But the same time operators want to reduce their per bit infrastructure cost with minimal capex and opex involved. MPLS had already been deployed widely to offer packet based services, then why not to use MPLS as transport too. This was the reason to add T-MPLS (Transport MPLS) for transport services too. T-MPLS was subset of MPLS. T-MPLS discussion was initially started by ITU-T in 2006. At that time, ITU shown their interest to use the existing MPLS framework defined by IETF and incorporate all the MPLS functionalities in T-MPLS.
After some time, the T-MPLS reached the stage where in some vendors started building their product by adding T-MPLS capabilities. But at the same time, IETF was also working on PWE3 to emulate any kind of access service over packet switched network over MPLS. On April 18, 2008 ITU and IETF had formed a joint working team to address all the issues and ceased the T-MPLS implementation. Thereafter, T-MPLS was changed to MPLS-TP.