Dell Brocade G620 Brocade 8.0.1 Fabric OS Command Reference - Page 84

aptPolicy 2 Device Based Routing Policy. Device-based routing is supported in FICON environments, and in open environments only when FICON coexists. With this policy, the path chosen for an ingress frame is based on the following items: • The ingress port on which the frame was received. • The FC address of the source fabric device (SID) for this frame. • The FC address of the destination fabric device (DID) for this frame. This policy optimizes the utilization of the available paths by allowing I/O traffic between different source fabric device (SID) or destination fabric device (DID) pairs to use different paths. As a result, every distinct flow in the fabric can take a different path through the fabric. Effectively, device based routing works the same as exchange-based routing but does not use the Originator Exchange ID (OXID) field. This helps to ensure that the exchanges between a pair of devices stay in order. Device-based routing is also a form of Dynamic Path Selection (DPS). DPS assigns communication paths between end devices in a fabric to egress ports in ratios proportional to the potential bandwidth of the ISL, ICL, or trunk group. When there are multiple paths to a destination, the input traffic is distributed across the different paths in proportion to the bandwidth available on each of the paths. This improves utilization of the available paths and reduces possible path congestion. 3 Exchange-based routing policy (default). With this policy, the path chosen for an ingress frame is based on all of the following items: • The ingress port on which the frame was received. • The FC address of the SID for this frame. • The FC address of the DID for this frame. • The FC OXID for this frame. This policy optimizes the utilization of the available paths by allowing I/O traffic between different SID, DID, or OXID pairs to use different paths. All frames received on an ingress port with the same SID, DID, or OXID parameters take the same path unless there is a fabric event. Refer to dlsSet for the definition of a fabric event. This policy does not support static routes. DLS is always enabled and the DLS setting cannot change with this policy. Examples To display the current APT policy: switch:admin> aptpolicy Current Policy: 3 3: Default Policy 1: Port Based Routing Policy 2: Device Based Routing Policy (FICON support only) 3: Exchange Based Routing Policy 60 Brocade Fabric OS Command Reference 53-1004112-02