HP StorageWorks 2/24 FW 07.00.00/HAFM SW 08.06.00 McDATA Products in a SAN Env - Page 101

Planning Considerations for Fibre Channel Topologies 3 TM TM TM TM Interswitch Link Fabric Connection Figure 3-9 Full Mesh Fabric Full-mesh fabrics provide increased resiliency over cascaded or ring fabrics and are well suited for applications that require any-to-any connectivity. If a single ISL fails, traffic is automatically routed through an alternate path. Mesh fabrics also form effective backbones to which other SAN islands can be connected. Traffic patterns through the fabric should be evenly distributed and overall bandwidth consumption low. When using low port-count fabric elements, mesh fabrics are best used when the fabric is not expected to grow beyond four or five switches. The cost of ISLs becomes prohibitive for larger mesh fabrics. In addition, full-mesh fabrics do not scale easily because the addition of a switch requires that at least one additional ISL be added from every existing switch in the fabric. If less than four fabric elements are used in a full-mesh fabric: • A two-switch full mesh fabric is identical to a two-switch cascaded fabric. • A three-switch full mesh fabric is identical to a three-switch ring fabric. Planning Considerations for Fibre Channel Topologies 3-15