Cabletron Systems 9F122-12 User Manual

Also see for 9E531-24: User guide

Contents

1-5Introductiondevice, and to have it pause its transmission while the receiving device processesthe frames already received. Flow control can be enabled or disabled on a port-by-port basis. Both devices must support the IEEE 802.3x standard for flow control towork.The 9E531-24 supports the following two types of flow control:• frame based 802.3x• back pressureFrame based 802.3x flow control is supported on all Ethernet ports operating inthe full duplex mode.Back pressure flow control is supported on all Ethernet ports operating in thestandard mode of operation.802.1p Port PriorityThe IEEE 802.1p standard is used to assign a default priority to the framesreceived without priority information in their tag header, and to map prioritizedframes to the appropriate transmit queues.The default priority-to-queue mappings are shown in Table 1-1. Thisconfiguration can be changed by the administrator.Switching OptionsThe 9E531-24 provides IEEE Standard-based 802.1 switching or SecureFastSwitching Virtual Network Services. In the 802.1 mode (the default mode ofoperation), the switch functions as an 802.1D switch. When VLANs areconfigured, it operates as an 802.1Q switch.Table 1-1. Priority Queuing ConfigurationPriority Indicator Transmit Queue7 36 35 24 23 12 01 00 1