Full label space reduction in MPLS networks: asymmetric merged tunneling

IEEE/ACM Trans. Networking

Stidsen

Fabregat

et al. 2008

Self Cite

Abstract-Most network operators have considered reducing LSR label spaces (number of labels used) as a way of simplifying management of underlaying Virtual Private Networks (VPNs) and therefore reducing operational expenditure (OPEX). The IETF outlined the label merging feature in MPLS-allowing the configuration of MultiPoint-to-Point connections (MP2P)-as a means of reducing label space in LSRs. We found two main drawbacks in this label space reduction scheme: ) it should be separately applied to a set of LSPs with the same egress LSR-which decreases the options for better reductions, and ) LSRs close to the edge of the network experience a greater label space reduction than those close to the core. The later implies that MP2P connections reduce the number of labels asymmetrically.In this article we propose a solution to these drawbacks achieved by stacking an additional label onto the packet header. We call this type of reduction Asymmetric Merged Tunnels (AMT). A fast framework for computing the optimal reduction using AMTs is proposed. Our simulations show that the label space can be reduced by up to 20% more than when label merging is used.

Section: Of the Mpls Forwarding Mechanism: The Label Space Of An Lsr mentioning

confidence: 99%

Section: A Detailed Testmentioning

confidence: 99%

Label Space Reduction in MPLS Networks: How Much Can A Single Stacked Label Do?

IEEE/ACM Trans. Networking

Stidsen

Fabregat

et al. 2008

Self Cite

“…Although MPLS packets may carry a stack of labels, which could be used for reducing label spaces even more [7], methods considering the stack are neither considered nor discussed in this letter. This letter focuses on the label merging method and in particular on the MERGING PROBLEM involved.…”

Section: Ulti Protocol Label Switching (Mpls) Is a Circuit-orientedmentioning

confidence: 99%

“…As for future work, a scenario in which the label space is improved by means of the label stacks could be considered, e.g. [7]. This new consideration may convert the label space reduction problem to NP-complete and therefore new heuristics and optimization models may be proposed.…”

Section: Conclusion and New Directionsmentioning

confidence: 99%

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

Fabregat

Marzo

2008

IEEE Trans. Commun.

Abstract-Most network operators have considered reducingLabel 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 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.

“…This fact has impelled the research on the optimal usage of the label space in MPLS-based networks. Previous works of the authors, such as [3], [4], [5], address the problem of the efficient usage of the label space for GMPLS-based networks without considering protection schemes.…”

Section: Introductionmentioning

confidence: 99%

Self-Protection: A novel protection scheme for All-Optical Packet Switching networks

2009 International Conference on Ultra Modern Telecommunications &Amp; Workshops

Pióro

Marzo

et al. 2009

All-Optical Packet Switching designs have evolved in the last years. However, all-optical packet forwarding functionalities are still limited. Several label assignation methods have been studied in order to efficiently use the small label space of the designs.In this paper, we present a novel scheme for Label Switched Path protection for networks with small label spaces, such as All-Optical Packet Switching technologies based on All-Optical Label Swapping. With the purpose of using as fewest labels as possible, the scheme has as basis using the same working paths as backup paths. The scheme is named Self-Protection. Properties and requirements of the schemes in mention are given in this paper. A brief analysis of the trade-off of the scheme is also provided.