Enterasys Networks 700 - Manual (Page 69)

Managing the Module 2-49
The MultiSwitch 700 Device View
priority queue. However, the MultiSwitch 700 will tag outgoing frames with the
full range of eight priority levels, so that upon reception, a device that supports
the entire range of priority queuing will forward the frame appropriately.
You can use NetSight Element Manager to configure the criteria that determine
the priority in which frames will be queued for transmission by your MultiSwitch
700 module. Several different criteria can be used to determine a frame’s
transmission queue order:
• The module and port at which the frame was received.
• The destination and/or source MAC address associated with the frame.
• A combination of destination and/or source MAC address and the frame’s
protocol type.
• The frame’s protocol type.
When you configure the transmission queue for a specific frame, an entry is made
in one of three priority tables maintained by the MultiSwitch 700 module. These
tables are used to determine which transmit queue to use — normal priority or
high priority — when forwarding frames.
• The ctPriorityExtPortTable maintains priority entries based on a frame’s receive
port.
• The ctPriorityExtMACTable maintains priority entries based on a frame’s
MAC-layer information.
• The ctPriorityExtPktTypeTable maintains priority entries based on the frame’s
protocol type.
The following sections discuss how to use the Port Priority Configuration
window, the MAC Based Priority Configuration window, and the Frame Priority
Configuration window to make entries in these transmit priority tables.
Configuring Priority Queuing Based on Receive Port
You can use the Port Priority Configuration window, Figure 2-21 , to determine
packet queuing based solely upon the port at which the packet was received. This
allows you to ensure that a connected user or LAN segment will have priority
when frames that were received on that port are queued for transmission.