FIBRE CHANNEL and IP SAN INTEGRATION(5)

The maturity and mission-critical deployment of Fibre Channel (FC) in storage area networks (SANs) creates a unique class of multi-terabit networks with demanding throughput, latency, scalability, robustness, and availability requirements. This paper revie

product. The lesson is that not all switches are designed equal. Switching architecture issues like head-of-line blocking and internal resource bandwidth (throughput or frame rate) limitations impact throughput, latency, and congestion loss, especially at higher offered load. Distance extension: Requirements for disaster recovery and business continuance (file/data mirroring, replication, and backup) are driving the deployment of SAN extension to deliver better performance and availability. In addition to robustness, stability, and performance considerations, it is important to understand the configurations, products, and protocols and system tuning parameters with respect to distance extension technology. We examine this topic later. Scaling the SAN: A large number of FC fabrics deployed today are small islands of fabrics that are not inter-networked into a large and connected SAN. Reasons for deploying isolated islands include early adopters learning new technology, difficulty and lack of confidence in management and operational stability of a large fabric, and insufficient business and operational drivers (for connecting islands of FC fabrics). However, there are many benefits of internetworking FC islands. Resource sharing (such as tape library for backup) and the ability to dynamically provision and allocate resource are some of the benefits. When scaling an FC SAN, it is important to maintain performance and availability properties. Since a FC fabric is similar to an IP layer 2 switching network, it is important to constrain the number of switches in a fabric so the resulting fabric is stable and robust. When interconnecting FC fabrics, it is critical to consider isolating FC fabric local initialization and services, while allowing servers and storage devices to be interconnected regardless of locality. This is an area of further research and standardization work, and currently ANSI T11 has a fabric extension study group addressing these topics. 3.0 FC & IP Integration & Challenges3.1 IP SAN DevelopmentsThe emergence of iSCSI, FCIP, and iFCP standards [5, 6, 7, 8, 9] enables IP technology to enhance the deployment and benefits of SANs. FCIP and iFCP protocols use a common framing and encapsulation design. We examine the applicability, design, and limitations of these technologies in the following sections. These protocols leverage the matured IPSec standard and technology to enable security (including authentication, integrity, and privacy). As part of the protocol suite, Internet Storage Name Service (iSNS) [10] provides a method to manage and configure names, registry, discovery, and zones for multi-protocol SANs. The use of Service Location Protocols (SLP) [11] to discover services and resources is another critical part of the standard.105