HP StorageWorks Fabric OS 6.1.1 administrator guide (5697-0235, December 2009)

Fabric OS 6.1.x administrator guide 291
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Optimizing fabric behavior
This chapter describes the Adaptive Networking features.
Adaptive networking overview
Adaptive Networking is a suite of tools and capabilities that enable you to ensure optimized behavior in
the SAN. Even under the worst congestion conditions, the Adaptive Networking features can maximize the
fabric behavior and provide necessary bandwidth for high-priority, mission-critical applications and
connections.
The following sections cover three features in the Adaptive Networking suite: Traffic Isolation, QoS Ingress
Rate Limiting, and QoS SID/DID Traffic Prioritization.
Top Talkers, which is another Adaptive Networking feature, is described briefly in this chapter and
described in detail in ”Administering advanced performance monitoring” on page 343.
Top Talkers
The Top Talkers feature provides real-time information about the top “n” bandwidth-consuming flows from a
set of a large number of flows passing through a specific port in the network. You can use Top Talkers to
identify the SID/DID pairs that consume the most bandwidth and can then configure them with certain
QoS attributes so they get proper priority.
The Top Talker feature is part of the optionally licensed Advanced Performance Monitoring feature. See
”Top Talker monitors” on page 350 for detailed information about Top Talkers.
Traffic Isolation
The Traffic Isolation feature allows you to control the flow of interswitch traffic by creating a dedicated path
for traffic flowing from a specific set of source ports (N_Ports). For example, you might use Traffic Isolation
for the following scenarios:
• To dedicate an ISL to high priority, host-to-target traffic.
• To force high volume, low priority traffic onto a given ISL to limit the effect on the fabric of this high
traffic pattern.
• To ensure that requests and responses of FCIP-based applications, such as tape pipelining use the same
VE_Port tunnel across a metaSAN.
Traffic Isolation is implemented using a special zone, called a Traffic Isolation zone (or TI zone). A TI zone
indicates the set of N_Ports and E_Ports to be used for a specific traffic flow. When a TI zone is activated,
the fabric attempts to isolate all inter-switch traffic entering from a member of the zone to only those E_Ports
that have been included in the zone. The fabric also attempts to exclude traffic not in the TI zone from using
E_Ports within that TI zone.
Figure 27 shows a fabric with a TI zone consisting of the following:
• N_Ports: “1,7”, “1,8”, “4,5”, and “4,6”
• E_Ports: “1,1”, “3,9”, “3,12”, and “4,7”.
The dotted line indicates the dedicated path from Domain 1 to Domain 4.