On optimal computation of MPLS label binding for multipoint-to-point connections

Most network operators have considered reducing Label Switched Routers (LSR) label spaces (i.e. the number of labels that can be used) as a means of simplifying management of underlaying Virtual Private Networks (VPNs) and, hence, reducing operational expenditure (OPEX). This letter discusses the problem of reducing the label spaces in MultiProtocol Label Switched (MPLS) networks using label merging - better known as MultiPoint-to-Point (MP2P) connections. Because of its origins in IP, MP2P connections have been considered to have treeshapes with Label Switched Paths (LSP) as branches. Due to this fact, previous works by many authors affirm that the problem of minimizing the label space using MP2P in MPLS - the MERGING PROBLEM - cannot be solved optimally with a polynomial algorithm (NP-complete), since it involves a harddecision problem. However, in this letter, the MERGING PROBLEM is analyzed, from the perspective of MPLS, and it is deduced that tree-shapes in MP2P connections are ir...

• Type: Journal
• Year: 2008
• Where: TCOM
• Authors: Fernando Solano, Ramón Fabregat, José-Luis Marzo
• Keywords: Label Switched Paths, Labels, Most Network Operators, TCOM 2008