T-MPLS
Encyclopedia
T-MPLS or Transport MPLS is a transport network layer technology that uses extensions to a subset of the existing MPLS
standards and is designed specifically for application in transport networks. Work to define T-MPLS was started by the ITU-T
in February 2006. It was intended specifically as a connection-oriented packet-switched (co-ps) application offering a simpler implementation by removing MPLS
features that are not relevant to co-ps applications and adding mechanisms that provide support of critical transport functionality.
ITU-T
ceased work on T-MPLS in December 2008, in favour of MPLS-TP
standardization.
T-MPLS uses the same architectural principles of layered networking that are used in other technologies like SDH and OTN
. Service providers have already developed management processes and work procedures based on these principles for use in networks that use those other technologies.
In this way T-MPLS was intended to provide a reliable packet-based technology that is familiar and also aligned with circuit-based transport networking; it supports current organizational processes and large-scale work procedures.
T-MPLS is a low cost Layer 2 technology that provides QoS
, end-to-end OA&M
and protection switching.
The following ITU-T
Recommendations exist for T-MPLS. These Recommendations will be superseded (i.e., replaced) by new revisions that apply to MPLS-TP
and reference the joint work being understaken by the ITU-T and IETF.
A further set of ITU-T
Recommendations were at a draft stage when work on T-MPLS was halted. These may be resumed at a later stage to reference the material developed as part of the MPLS-TP
effort.
After IETF raised concerns over T-MPLS technology, mainly about incompatibility with the already established IP/MPLS, the ITU-T and the IETF started a joint activity to solve potential issues. The decision was to transfer control to IETF to develop a new MPLS profile specialized for transport (MPLS-TP
) with input from ITU recommendations
A new activity was added to the charter of the MPLS
working group of IETF.
Multiprotocol Label Switching
Multiprotocol Label Switching is a mechanism in high-performance telecommunications networks that directs data from one network node to the next based on short path labels rather than long network addresses, avoiding complex lookups in a routing table. The labels identify virtual links between...
standards and is designed specifically for application in transport networks. Work to define T-MPLS was started by the ITU-T
ITU-T
The ITU Telecommunication Standardization Sector is one of the three sectors of the International Telecommunication Union ; it coordinates standards for telecommunications....
in February 2006. It was intended specifically as a connection-oriented packet-switched (co-ps) application offering a simpler implementation by removing MPLS
Mpls
MPLS or Mpls can refer to:* Minneapolis, Minnesota, United States* Multiprotocol Label Switching, a data-carrying mechanism in computer networking...
features that are not relevant to co-ps applications and adding mechanisms that provide support of critical transport functionality.
ITU-T
ITU-T
The ITU Telecommunication Standardization Sector is one of the three sectors of the International Telecommunication Union ; it coordinates standards for telecommunications....
ceased work on T-MPLS in December 2008, in favour of MPLS-TP
MPLS-TP
MPLS-TP or MPLS Transport Profile is a profile of MPLS whose definition has been commenced by the IETF. It will be designed for use as a network layer technology in transport networks. Its design will be a continuation of the work started by the transport network experts of the ITU-T, specifically...
standardization.
T-MPLS uses the same architectural principles of layered networking that are used in other technologies like SDH and OTN
Optical Transport Network
ITU-T defines an Optical Transport Network as a set of Optical Network Elements connected by optical fibre links, able to provide functionality of transport, multiplexing, switching, management, supervision and survivability of optical channels carrying client signals...
. Service providers have already developed management processes and work procedures based on these principles for use in networks that use those other technologies.
In this way T-MPLS was intended to provide a reliable packet-based technology that is familiar and also aligned with circuit-based transport networking; it supports current organizational processes and large-scale work procedures.
T-MPLS is a low cost Layer 2 technology that provides QoS
Quality of service
The quality of service refers to several related aspects of telephony and computer networks that allow the transport of traffic with special requirements...
, end-to-end OA&M
OA&M
Operations, administration and management or operations, administration and maintenance is a general term used to describe the processes, activities, tools, standards, etc involved with operating, administering, managing and maintaining any system...
and protection switching.
The following ITU-T
ITU-T
The ITU Telecommunication Standardization Sector is one of the three sectors of the International Telecommunication Union ; it coordinates standards for telecommunications....
Recommendations exist for T-MPLS. These Recommendations will be superseded (i.e., replaced) by new revisions that apply to MPLS-TP
MPLS-TP
MPLS-TP or MPLS Transport Profile is a profile of MPLS whose definition has been commenced by the IETF. It will be designed for use as a network layer technology in transport networks. Its design will be a continuation of the work started by the transport network experts of the ITU-T, specifically...
and reference the joint work being understaken by the ITU-T and IETF.
| Recommendation | Title |
|---|---|
| G.8110.1 | Architecture of Transport MPLS (T-MPLS) Layer Network |
| G.8112 | Interfaces for the Transport MPLS (T-MPLS) Hierarchy |
| G.8121 | Characteristics of Transport MPLS equipment functional blocks |
| G.8131 | Linear protection switching for Transport MPLS (T-MPLS) networks |
| Y.Sup4 ex G.8113 (draft) |
Requirements for OAM function in T-MPLS based networks |
A further set of ITU-T
ITU-T
The ITU Telecommunication Standardization Sector is one of the three sectors of the International Telecommunication Union ; it coordinates standards for telecommunications....
Recommendations were at a draft stage when work on T-MPLS was halted. These may be resumed at a later stage to reference the material developed as part of the MPLS-TP
MPLS-TP
MPLS-TP or MPLS Transport Profile is a profile of MPLS whose definition has been commenced by the IETF. It will be designed for use as a network layer technology in transport networks. Its design will be a continuation of the work started by the transport network experts of the ITU-T, specifically...
effort.
| Draft Recommendation | Title |
|---|---|
| G.8114 (draft) | Operation & Maintenance mechanisms for T-MPLS layer networks |
| G.8132 (draft) | Shared Protection Ring switching for T-MPLS networks |
After IETF raised concerns over T-MPLS technology, mainly about incompatibility with the already established IP/MPLS, the ITU-T and the IETF started a joint activity to solve potential issues. The decision was to transfer control to IETF to develop a new MPLS profile specialized for transport (MPLS-TP
MPLS-TP
MPLS-TP or MPLS Transport Profile is a profile of MPLS whose definition has been commenced by the IETF. It will be designed for use as a network layer technology in transport networks. Its design will be a continuation of the work started by the transport network experts of the ITU-T, specifically...
) with input from ITU recommendations
A new activity was added to the charter of the MPLS
Mpls
MPLS or Mpls can refer to:* Minneapolis, Minnesota, United States* Multiprotocol Label Switching, a data-carrying mechanism in computer networking...
working group of IETF.