Flow control between fiber channel and wide area networks

摘要

Multiple fiber channel (FC) storage area networks (SANs) are interconnected over wide-area networks (WANs) to form a long-distance (e.g., greater than about 10 km) distributed storage area network (DSAN) that includes FC to Internet Protocol (IP) over WAN (e.g., SONET or gigabit Ethernet (GE)) gateways that interwork the FC buffer-to-buffer and IP/WAN flow-control mechanisms appropriate to either the SONET or GE link layers using an additive increase, multiplicative decrease (AIMD) congestion avoidance algorithm. The gateways effectively spoof the FC buffer-to-buffer credit mechanism on the FC-interface side of the gateway, while using an IP Internet control message protocol (ICMP) quench mechanism on all WAN links and additionally the IEEE 802.3 pause packet flow control mechanism on gigabit Ethernet (GE) WAN links in combination, in both cases, with a rate-throttling mechanism at the FC<->IP converter.