HP Cisco Nexus 5000 Cisco MDS 9000 Family CLI Configuration Guide - Release 4. - Page 671

Chapter 26 Configuring Fibre Channel Routing Services and Protocols In-Order Delivery Send documentation comments to [email protected] In-Order Delivery In-Order Delivery (IOD) of data frames guarantees frame delivery to a destination in the same order that they were sent by the originator. Some Fibre Channel protocols or applications cannot handle out-of-order frame delivery. In these cases, switches in the Cisco MDS 9000 Family preserve frame ordering in the frame flow. The source ID (SID), destination ID (DID), and optionally the originator exchange ID (OX ID) identify the flow of the frame. On any given switch with IOD enabled, all frames received by a specific ingress port and destined to a certain egress port are always delivered in the same order in which they were received. Use IOD only if your environment cannot support out-of-order frame delivery. Tip If you enable the in-order delivery feature, the graceful shutdown feature is not implemented. This section includes the following topics: • About Reordering Network Frames, page 26-13 • About Reordering PortChannel Frames, page 26-14 • About Enabling In-Order Delivery, page 26-14 • Enabling In-Order Delivery Globally, page 26-16 • Enabling In-Order Delivery for a VSAN, page 26-16 • Displaying the In-Order Delivery Status, page 26-16 • Configuring the Drop Latency Time, page 26-17 • Displaying Latency Information, page 26-17 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 26-5 Route Change Delivery Switch 1 Switch 2 Switch 3 Frame 2 Frame 1 Old path New path 85474 Frame 4 Frame 3 Switch 4 OL-18084-01, Cisco MDS NX-OS Release 4.x Cisco MDS 9000 Family CLI Configuration Guide 26-13