HP Surestore 64 Planning Guide - Page 89

Fabric Topology Limits Operation of multiple directors in a fabric topology is subject to the following topology limits. Consider the impact of these limits when planning the fabric. • Fabric Elements Up to 16 interconnected directors are supported in a single fabric. Each fabric element is defined by a unique domain identification (domain ID) that ranges between 1 and 15. A domain ID of 0 is invalid. • Inhomogeneous fabric Vendor interoperability in the fabric environment is supported, therefore fabric elements can include directors, other managed products, and products supplied by other OEMs. To determine if interoperability is supported for a product, or if communication restrictions apply, refer to the supporting publications for the product or contact your local HP sales office for the latest configuration information. • Number of ISLs The maximum number of ISLs per director is 32 (one-half of the number of director ports). • Hop count The supported limit of ISL connections traversed (hop count) in a single path through the fabric is two, not to exceed 10 kilometers. Note The hop count is equal to the number of ISL connections traversed in a single path, not the total number of ISL connections between devices. As shown in Figure 19, the number of ISL connections between switch S1 and S2 is four, while the number of hops is one. Factors to Consider When Implementing a Fabric Topology Director-based fabrics offer scalable, high-performance, and high- availability connectivity solutions for the enterprise. To enable a multiswitch fabric, directors must be defined to the HP EFC Manager application, and must be physically cabled to form the requisite ISL Planning Considerations Multiswitch Fabric Support 75