HP StorageWorks 2/24 FW 07.00.00/HAFM SW 08.06.00 McDATA Products in a SAN Env - Page 188

Implementing SAN Internetworking Solutions 4 • Does not require Fibre Channel BB_Credits assigned to the link because buffering is built in to the GFP function to enable long-distance transmission of storage traffic. • Creates a routed iSAN or one logical Fibre Channel fabric through a stretched E_Port connection, depending upon the protocol and if one or more SAN routers are deployed in the link. - Native FCP or FICON (unrouted) - The top data path in Figure 4-10 illustrates native FCP or FICON extended-distance connectivity through an unrouted SONET interface. GFP interfaces provide required link buffering and flow control. The stretched E_Port connection is vulnerable to disruptions caused by events at each site or to disruptions caused by problems with the extended-distance SONET link. - Native FCP (routed) - The middle data path in Figure 4-10 illustrates native FCP extended-distance connectivity through a routed SONET interface. GFP interfaces provide required link buffering and flow control. A single Eclipse 2640 SAN router at one end of the link provides R_Port connectivity and SAN isolation (not intelligent port connectivity or protocol conversion). The routed SAN connection ensures disruptions at one site are isolated and not allowed to propagate to other locations. This connection does not support FICON operation. - iFCP (routed) - The bottom data path in Figure 4-10 illustrates iFCP extended-distance connectivity through a routed SONET interface. GFP interfaces provide SONET connectivity but are not required for link buffering and flow control. Eclipse 1620 SAN routers at each end of the link provide intelligent port connectivity and iFCP protocol conversion. The routed iSAN connection ensures disruptions at one site are isolated and not allowed to propagate to other locations. This connection does not support native FCP or FICON operation. Several network service providers provide metropolitan and intercity SONET and SDH transport services. Long-distance SONET and SDH circuits are common and the technology does not suffer the cost and availability restrictions inherent to dark fiber and WDM. The technology provides low overhead, high bandwidth, point-to-point transport of storage traffic, and is a cost-effective choice for distanceextended data replication. 4-44 McDATA Products in a SAN Environment - Planning Manual