Specifications

3
Planning Considerations for Fibre Channel Topologies
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Planning Considerations for Fibre Channel Topologies
— Fabric A zoned and Fabric B zoned - The fabrics join
successfully only if the zone sets can be merged. If the fabrics
cannot join, the connecting E_Ports segment and the fabrics
remain independent.
Zone sets for two directors or switches are compatible (the fabrics
can join) only if the zone names for each fabric element are
unique. The zone names for two fabric elements can be the same
only if the zone member WWNs are identical for each duplicated
zone name.
General Fabric Design Considerations
To be effective, the fabric topology design must:
• Solve the customer’s business problem and provide the required
level of performance.
• Meet the customer’s requirements for high availability.
• Be scalable to meet future requirements.
Fabric Initialization
When multiple directors or switches are connected, E_Port (ISL)
communication must be established between fabric elements and the
fabric must be initialized. During fabric initialization, the fabric
elements:
• Establish the operating mode for connected E_Port pairs and
exchange link parameters (E_Port names, timeout values, class-
specific information, and flow control parameters).
• Exchange fabric parameters, select a principal switch, and assign
Domain_IDs to all switches.
• Employ a routing protocol to establish the shortest path through
the fabric and program route tables for each fabric element.
• Exchange the active zone set to ensure uniform zoning is enforced
between all fabric elements.
Fabric initialization is not a serial process. The process executes
concurrently across all ISLs in the fabric, causing a massive flood of
Class F traffic that must processed to the embedded port of each
fabric element within a specified (fabric-wide) E_D_TOV.