Installation guide

Flow Control
1-6
1.6 FLOW CONTROL
Flow control is a method of managing the flow of frames between two devices. It ensures that a
transmitting device does not overwhelm 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 module supports frame-based 802.3x flow control. 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 not supported on ports operating in the half-duplex mode.
1.7 802.1p PORT PRIORITY
The 802.1p 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 802.1p port priority is part of the IEEE 802.1D
standard.
1.8 MANAGEMENT
Management of the module can be either in-band or out-of-band. In-band remote management is
possible through any SNMP-compliant Network Management Software, such as the Enterasys
Networks’ NetSight™ management product. In-band management using Telnet and Enterasys
Networks’ Webview™ is also provided. Out-of-band Local Management is provided through the
RJ45 COM port on the front panel using a VT100 terminal or a VT100 terminal emulator.
Local Management provides the ability to manage the module. Refer to the MATRIX E5 Series
Modules Local Management User’s Guide for more information.
1.9 SWITCHING OPTIONS
The module provides 802.1Q switching between all of the front panel interfaces. In the 802.1Q
mode (the default mode of operation), the module functions as an 802.1D switch until you
configure VLANs. Up to 1024 VLANs can be configured.
IEEE 802.1Q switching allows migration to Virtual Network technologies without requiring the
replacement of existing equipment.