High-Performance Hybrid-Switching Optical Router for IP over WDM Integration

Abstract

Because pure electrical routers with their bandwidth limitations can hardly keep up with the tremendous traffic growth in the Internet, optical routers based on various optical switching techniques including optical wavelength switching (OWS), optical burst switching (OBS), and optical packet switching (OPS) have been suggested to cope with this problem. However, because OBS and OPS are both in their early experimental phase and OWS only provides coarse granularity switching, a hybrid-switching optical router with combined OWS and electrical packet switching is a necessity in order to accommodate the entire multi-granularity traffic with multiservice requirements in a cost-effective manner. Its coordination capability of optical circuit switching and electrical packet switching enables efficient/intelligent usage of network resources. In this paper, we first review research and developments of such IP routers employing optical switching/interconnection techniques and examine how these techniques can be used inside routers to scale node capacity and to improve optical Internet performance. We also present and study the performance of a terabit optical router with an optical-electrical hybrid-switching fabric. The node architecture is based on the idea of IP over WDM integration with Generalized Multi-Protocol Label Switching (GMPLS). The network-level performance evaluations show that the proposed hybrid-switching optical router is a cost-effective solution for building the next generation GMPLS-based multi-granularity optical Internet.

Multi-Granular Optical Cross-Connect: Design, Analysis, and Demonstration

“…In [8,9], NTT and Fujitsu demonstrated burst switching with GMPLS-based two-way signaling protocol, utilizing planar lightwave circuit (PLC) and MEMS switches. In [10], commercial PLC switches were adopted to construct a 1616 non-blocking switch matrix with a switching speed of less than 3 ms. OBS schemes with hybrid optical and electrical switching technologies have been investigated in the past [11]. A recent study demonstrated that a PLZT switch (lead lanthanum zirconate titanate, [12]) with shared wavelength conversion allowed variable-length 3.5 ns OBS.…”

“…Thus, according to Yoo et al in [5], Table I identifies possible switch fabrics for the development of a multi-granular switch. A detailed discussion based on the attributes mentioned above can be found in Wei et al [11] and Papadimitriou et al [6]. Clearly, one of the most appropriate slow switching technologies is the optical MEMS switch, since it is already a mature technology under production and because of the high dimensions available at low cost [14,15].…”