HP StorageWorks 2/24 FW 07.00.00/HAFM SW 08.06.00 McDATA Products in a SAN Env - Page 103

Planning Considerations for Fibre Channel Topologies 3 Tier 2 Devices TM TM 10/100 RST TM PWR ERR Tier 1 Device Core Director TM 10/100 RST 31 29 27 25 23 TM 21 19 17 15 30 28 26 24 22 20 18 13 11 9 7 5 3 1 16 14 12 10 8 6 4 2 0 PWR ERR 10/100 RST TM PWR ERR TM TM 10/100 RST 31 29 27 25 23 TM 21 19 17 15 30 28 26 24 22 20 18 13 11 9 7 5 3 1 16 14 12 10 8 6 4 2 0 PWR ERR Edge Switches Core Director Tier 1 Device TM TM 10/100 RST TM PWR ERR 10/100 RST 31 29 27 25 23 TM 21 19 17 15 30 28 26 24 22 20 18 13 11 9 7 5 3 1 16 14 12 10 8 6 4 2 0 PWR ERR TM 10/100 RST 31 29 27 25 23 TM 21 19 17 15 30 28 26 24 22 20 18 13 11 9 7 5 3 1 16 14 12 10 8 6 4 2 0 PWR ERR 10/100 RST TM PWR ERR Edge Switches Interswitch Link Fabric Connection Tier 2 Devices Figure 3-10 2-by-14 Core-to-Edge Fabric Each edge switch connects (through at least one ISL) to each core switch but not to other edge switches. There are typically more device connections to an edge switch than ISL connections; therefore edge switches act as consolidation points for servers and storage devices. The ratio of ISLs to device connections for each switch is a function of device performance. For additional information, refer to ISL Oversubscription. Fibre channel devices (servers and storage devices) connect to core or edge fabric elements in tiers. These tiers are defined as follows: • Tier 1 - A Tier 1 device connects directly to a core director or switch. Tier 1 devices are typically high-use or high-I/O devices that consume substantial bandwidth and should not be connected through an ISL. In addition, fibre connection (FICON) devices cannot communicate through E_Ports (ISLs) and must use Tier 1 connectivity. For additional information, refer to FCP and FICON in a Single Fabric. Planning Considerations for Fibre Channel Topologies 3-17