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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 tree- shapes 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 hard- decision 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 irrelevant. By overriding this tree-shape consideration, it is possible to perform label merging in polynomial time. Based on how MPLS signaling works, this letter proposes an algorithm to compute the minimum number of labels using label merging: the Full Label Merging algorithm. As conclusion, we reclassify the Merging Problem as Polynomial-solvable, instead of NP-complete. In addition, simulation experiments confirm that without the tree-branch selection problem, more labels can be reduced

© IEEE Transactions on Communications, 2008, vol. 56, p. 1056-1059

IEEE

Autor: Solano Donado, Fernando
Fabregat Gesa, Ramon
Marzo i Lázaro, Josep Lluís
Data: 2008
Resum: 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 tree- shapes 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 hard- decision 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 irrelevant. By overriding this tree-shape consideration, it is possible to perform label merging in polynomial time. Based on how MPLS signaling works, this letter proposes an algorithm to compute the minimum number of labels using label merging: the Full Label Merging algorithm. As conclusion, we reclassify the Merging Problem as Polynomial-solvable, instead of NP-complete. In addition, simulation experiments confirm that without the tree-branch selection problem, more labels can be reduced
Format: application/pdf
Cita: Solano, F., Fabregat, R., i Marzo, J.L. (2008). On optimal computation of MPLS label binding for multipoint-to-point connections. IEEE Transactions on Communications, 56, 7, 1056-1059. Recuperat 19 maig 2010, a http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=4568446
ISSN: 0090-6778
Accés al document: http://hdl.handle.net/10256/2327
Llenguatge: eng
Editor: IEEE
Col·lecció: Reproducció digital del document publicat a: http://dx.doi.org/10.1109/TCOMM.2008.050601
Articles publicats (D-ATC)
És part de: © IEEE Transactions on Communications, 2008, vol. 56, p. 1056-1059
Drets: Tots els drets reservats
Matèria: Arbres (Teoria de grafs)
MPLS (Norma)
Protocols de xarxes d’ordinadors
Computer network protocols
MPLS standard
Trees (Graph theory)
Virtual Private Network
Títol: On optimal computation of MPLS label binding for multipoint-to-point connections
Tipus: info:eu-repo/semantics/article
Repositori: DUGiDocs

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