With the widespread deployment of IP over WDM networks, it becomes necessary to develop dynamic lightpath and topology reconfiguration mechanisms and reconfiguration triggers that can effectively exploit WDM reconfigurability. A reconfiguration model for overlay IP/WDM networks is introduced. An IP over WDM network testbed has been set up using Telcordia MONET WADMs and IP routers. The testbed network and software architecture is presented and the trafficengineering experiments and convergence measurements conducted over the testbed are reported. I. IP/WDM INTERNETWORKING ARCHITECTUREAs the emergence of multi protocol lambda switching (MPλS) control technique and optical packet switching equipment, there are two IP over WDM networking architectures: IP over reconfigurable WDM and IP over switched WDM [1], [2]. The former is constructed upon a circuit-switched WDM network whereas the latter is based on a packet or label switched WDM network. Under the first architecture, established circuits form a WDM lightpath topology that is reconfigurable in response to traffic changes and/or network planning. In the second architecture, e.g. in the case of Optical Label Switching, there is a unified IP/WDM topology build upon the packet-switched WDM network. In a switched WDM network, optical headers are attached to the payload data and are processed at each network switch. We focus on IP over reconfigurable WDM networks in this paper. The reconfigurable IP/WDM network we envision consists of IP routers attached to a WDM core network, or interconnected OXCs that are capable of processing IP packets. The reconfigurable IP/WDM inter-networking architecture is defined essentially by the organization of the WDM control plane. Three network models have been proposed, overlay, peer, and augmented model [3]. Under the overlay network model, the IP routing, topology discovery and distribution, and signaling protocols are independent of the routing, topology discovery and distribution, and signaling at the WDM layer. There are two alternatives to interface between IP layer and WDM layer. First, the two layers can communicate through the WDM This research is partially funded by the US Government DARPA NGI SuperNet project under the contract F30602-98-C-0202. network management system. There is no direct interface between IP network and WDM network. This is similar to IP over ATM Soft Permanent Circuits (SPVC). Second, the two networks can interface directly through Optical User Network Interface (O-UNI). O-UNI is an edge module for the WDM network to serve IP client requests. O-UNI only support interfaces of lightpath request, deletion, and query because of the limited information shared between the IP and WDM layer. With the peer network model, control in the IP/WDM network is facilitated by MPLS control plan.Each WDM node consists of an integrated IP router and an OXC. The interaction between the router and OXC is still being developed. Signaling among various nodes is achieved using CR-LDP and RSVP with proper extensions. Under thi...
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.