We argue for the refactoring of the IP control plane to provide direct expressibility and support for network-wide goals relating to all fundamental functionality: reachability, performance, reliability and security. This refactoring is motivated by trends in operational practice and in networking technology. We put forward a design that decomposes functionality into information dissemination and decision planes. The decision plane is formed by lifting out of the routers all decision making logic currently found there and merging it with the current management plane where network-level objectives are specified. What is left on each router is a wafer-thin control plane focused on information dissemination and response to explicit instructions for configuring packet forwarding mechanisms. We discuss the consequences, advantages and challenges associated with this design. 1.

The performance and reliability of the Internet depend, in large part, on the operation of the underlying routing protocols. Today’s IP routing protocols compute paths based on the network topology and configuration parameters, without regard to the current traffic load on the routers and links. The responsibility for adapting the paths to the prevailing traffic falls to the network operators and management systems. This chapter discusses the modeling and computational challenges of optimizing the tunable parameters, starting with conventional intradomain routing protocols that compute shortest paths as the sum of configurable link weights. Then, we consider the problem of optimizing the interdomain routing policies that control the flow of traffic from one network to another. Optimization based on local search has proven quite effective in grappling with the complexity of the routing protocols and the diversity of the performance objectives, and tools based on local search are in wide use in today’s large IP networks. 1

We argue for the refactoring of the IP control plane to support network-wide objectives and control. We put forward a design that refactors functionality into a novel 4D architecture composed of four separate planes: decision, dissemination, discovery and data. All decision-making logic is moved out of routers along with current management plane functions to create a logically centralized decision plane, where network-level objectives and policies are specified and enforced by direct configuration of states on individual network elements. Pulling much of the control state and logic out of the routers enables both simpler protocols, which do not have to embed decision-making logic, and more powerful decision algorithms for implementing sophisticated goals. Remaining on the routers is a wafer-thin class of intrinsically distributed control functions. These support the discovery plane, consisting of elementary functions to discover topology and network state, and the dissemination plane, consisting of elementary functions to distribute explicit instructions to manipulate the data plane forwarding mechanisms.

Abstract. MultiProtocol Label Switching (MPLS) is used today inside most large Service Provider (SP) networks. In this paper, we analyze the establishment of interdomain MPLS LSPs with QoS constraints. These LSPs cross diverse SP networks that may belong to different companies. We show that using the standard BGP route for the establishment of such LSPs is not sufficient. We propose two path establishment techniques that rely on RSVP-TE and make use of Path Computation Elements (PCEs). Our simulations show that these techniques increase the number of constrained MPLS LSPs that can be established across domain boundaries. 1

(MPLS-TE) Routing Systems have been proposed in the literature to achieve optimization of resources utilization, Quality-of-Service (QoS) and Fast Recovery. This paper proposes a generic architecture for MPLS-TE Routing Systems, which aims to ease the classification and the analysis of these systems. Then this paper defines a set of MPLS-TE classification criteria. The combination of these criteria leads to the identification of main families of MPLS-TE Routing Systems which are finally compared and qualitatively evaluated according to a set of metrics. I.

We argue for the refactoring of the IP control plane to provide direct expressibility and support for network-wide goals relating to all fundamental functionality: reachability, performance, reliability and security. This refactoring is motivated by trends in operational practice and in networking technology. We put forward a design that decomposes functionality into information dissemination and decision planes. The decision plane is formed by lifting out of the routers all decision making logic currently found there and merging it with the current management plane where network-level objectives are specified. What is left on each router is a wafer-thin control plane focused on information dissemination and response to explicit instructions for configuring packet forwarding mechanisms. We discuss the consequences, advantages and challenges associated with this design.