An in-band signaling protocol for optical packet switching networks

Recent advances in optical networking reveal that all optical networks offe ring multigigabit rate per wavelength will soon become economical as the un derlying backbone in wide-area networks, in which optical switch plays a ce ntral role. One of the central issues is the design of efficient signaling protocols which can support diversified traffic types, in particular the bu rsty IP traffic. This paper introduces a novel signaling protocol called the sampling probe algorithm (or SPA) to be used in a class of optical packet switching system s based on wavelength division multiplexing (WDM), The proposed scheme take s a drastically different approach from all existing signaling protocols. T he salient features are 1) the pretransmission coordination is using an in- band signaling protocol, and thus does not require separate control channel (s) for transmission coordination; 2) the protocol is based on a reservatio n (connection) scheme which is capable of supporting multimedia traffic; 3) a gated service is adopted in which each successful reservation allows mul tiple packets (train of packets) to be transmitted, which can significantly reduce the per packet overhead; 4) the scheduling algorithm is adaptive by allowing flexible assignment of bandwidth on-demand; 5) the channel status gathering is done in a distributed fashion, and uses a passive listening m echanism, which itself does not interfere with packet transmissions. The re sults demonstrate that the proposed in-band signaling protocol can achieve high throughput and stability under heavy traffic condition.