Flow Control

1.10 FLOW CONTROL

Flow control is a method of managing the flow of frames between two devices. It ensures that a transmitting device does not saturate a receiving device with data. This is accomplished by the transmitting device pausing its transmission while the receiving device processes the frames already received.

The 6H352-25 supports the following two types of flow control:

Frame based 802.3x

Back pressure

Frame based 802.3x flow control is supported on all Ethernet ports operating in the full-duplex mode. Flow control can be enabled or disabled on a port-by-port basis.

Back pressure flow control is supported on all Ethernet ports operating in the half-duplex mode of operation. Flow control can be enabled or disabled on a port-by-port basis.

1.11 GARP SWITCH OPERATION

Some or all ports on the switch may be activated to operate under the Generic Attribute Registration Protocol (GARP) applications, GARP VLAN Registration Protocol (GVRP) and/or GARP Multicast Registration Protocol (GMRP).

GARP is a protocol, or set of rules, that outlines a mechanism for propagating the port state and/or user information throughout a bridged LAN to keep track of users and VLANs on the network fabric. MAC bridges and end users alike can take part in the registration and de-registration of GARP attributes such as VLAN and multicast group membership. For more details on how GVRP and GMRP handle frames under GARP, and how to configure the switch ports to take advantage of this operation, refer to the Enterasys Networks MATRIX E7 Series and SmartSwitch 6000 Series Modules Local Management User’s Guide.

1.12 802.1 PORT PRIORITY

The 802.1 port priority is used to assign a default priority to the frames received without priority information in their tag header, map prioritized frames to the appropriate transmit queues, and prioritize frames according to protocol type. The 802.1 port priority is part of the IEEE 802.1D standard.

1-6Introduction

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Enterasys Networks 6H352-25 manual Flow Control, Garp Switch Operation, 12 802.1 Port Priority