Stephen Suryaputra

Simple wavelength assignment protocol

IP routers can be coupled with wavelength-selective optical cross- connects to support existing Internet infrastructure in a wavelength division multiplexing (WDM) optical network. Because optical wavelength routing is transparent to IP, packets can bypass traditional forwarding and pass directly through the optical cross-connect, resulting in very high throughput and low delay routing. This approach shares features with label switching, but wavelengths are much more scarce resource than labels. Because optical switches have larger switching times than electronic switches, and wavelength conversions are expensive, wavelength label swapping is not easily done. Wavelength label assignments must consider these limitations to be practical in an optical environment. The performance of an instance of this approach, called Packet over Wavelengths (POW) has been simulated and studied. A new signaling protocol, Simple Wavelength Assignment Protocol (SWAP) is devised to be POW signaling protocol. SWAP takes into account the optical device limitations, and is designed to minimize wavelength conversion, utilize wavelengths with the merging of flows, and reduce the reconfiguration of optical switches. SWAP, to our knowledge, is the first approach to combine signaling and wavelength assignment in an on- line protocol. This paper describes high level SWAP design challenges, decision, and overhead.

How Many Wavelengths Do We Really Need in an Internet Optical Backbone

Coupling Internet protocol (IP) routers with wavelength-selective optical crossconnects makes it possible to s upport existing Internet infrastructur in a wavelength-division multiplexing optical network. Because optical wavelength routing is transparent to IP, very high throughput and low delay can be achieved when packets are made to bypass the IP forwarding process by being switched directly through the optical cross-connect. One version of this approach is called packets over wavelengths (POW). This paper presents the POW architecture in detail and discusses its salient features. Realistic simulations of the POW that use actual packet traces in a well-known Inte rnet backbone network reveal the level of pe rformance that can be expected from POW under various options. Specifically, the fraction of packets that are switched through the crossconnect is evaluated as a function of the number wavelengths and the degree of flow aggregation that can be achieved. The resulting analysis, conducted in the context of the very-high bandwidt network service (vBNS) Internet backbone, suggests that as few as four wavelengths combined with a high degree of traffic aggregation can carry more than 98% of IP packets in the str eamlined switched mode. In cases where it is not po ssible to aggregate traffic, the deployment of wavelengthmerging technology would increase the fraction of IP packets carried in streamlined switched mode by up to 52%.