Cisco Nexus 5000 Series Switch CLI Software Configuration Guide, NX-OS 4.0(1a)N1 (OL-16597-01, January 2009)

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40-11
Cisco Nexus 5000 Series Switch CLI Software Configuration Guide
OL-16597-01
Chapter 40 Configuring Fibre Channel Routing Services and Protocols
In-Order Delivery
This section includes the following topics:
• About Reordering Network Frames, page 40-11
• About Reordering SAN Port Channel Frames, page 40-11
• About Enabling In-Order Delivery, page 40-12
• Enabling In-Order Delivery Globally, page 40-12
• Enabling In-Order Delivery for a VSAN, page 40-13
• Displaying the In-Order Delivery Status, page 40-13
• Configuring the Drop Latency Time, page 40-13
• Displaying Latency Information, page 40-14
About Reordering Network Frames
When you experience a route change in the network, the new selected path may be faster or less
congested than the old route.
Figure 40-4 Route Change Delivery
In Figure 40-4, the new path from Switch 1 to Switch 4 is faster. In this scenario, Frame 3 and Frame 4
may be delivered before Frame 1 and Frame 2.
If the in-order guarantee feature is enabled, the frames within the network are delivered as follows:
• Frames in the network are delivered in the order in which they are transmitted.
• Frames that cannot be delivered in order within the network latency drop period are dropped inside
the network.
About Reordering SAN Port Channel Frames
When a link change occurs in a SAN port channel, the frames for the same exchange or the same flow
can switch from one path to another faster path.
Switch 1 Switch 2 Switch 3
Switch 4
Frame 2 Frame 1
Frame 4 Frame 3
Old path
New path
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