Enterasys Networks 700 manual Standard Mode, Full Duplex

The MultiSwitch 700 Device View

WARNING

For standard Ethernet interfaces, Full Duplex should only be enabled on an interface that has a connection to a single destination address at the other end of the connection (i.e., it is not a segment with an attached repeater cascading the connection to multiple destination addresses).

Full Duplex mode disables the collision detection circuitry at the interface, so that both Transmit and Receive wires can be used simultaneously. With a single destination address at the other end of the connection (for example, if the connection was to a full duplex interface on another switching module, or if a single file server was connected to the full duplex switch port), this essentially doubles the available bandwidth from 10 Mbit/sec to 20 Mbit/sec. The interface at the other end of the connection must also have Full Duplex enabled at the attached interface.

Full Duplex mode must be disabled if the interface is communicating with multiple destinations simultaneously (i.e., if a repeater is cascaded from the interface), since Ethernet relies on Collision Sense for proper operation.

Similarly, an FDDI Full Duplex connection must also only be run point-to-point between two supporting FDDI interfaces (e.g., another DELHF-UA), since the dual bandwidth is attained by running data on both primary and secondary paths simultaneously. Since Full Duplex overrides standard FDDI protocol (and eliminates ring redundancy), it will not operate in a “ring” configuration, but only as a point-to-point high speed data trunk between hubs. You must use Local Management to configure your DELHF-UA for Full Duplex operation prior to making physical connections. Refer to your Local Management Guide for more information.

Use the options in this window to select the desired mode:

Standard Mode

In Standard Mode, an interface can only either transmit or receive at any given time, and must wait for one activity to be completed before switching to the next activity (receive or transmit). In this mode, standard wire speeds (10 Mbps for Ethernet, 100 Mbps for FDDI) are available.

Full Duplex

In Full Duplex Mode, an interface can both receive and transmit packets at the same time, effectively doubling the available wire speed to 20 Mbps (for Ethernet) or 200 Mbps (for FDDI).

Be sure to click on Apply to set your changes; note that the interface’s current mode can be determined by the field selected in the window.

Configuring Fast Ethernet Ports on First Generation Modules

The Port Configuration window available for Fast Ethernet ports on first generation modules (e.g., a DELF3-UI, DELFX-UI, or DELTX-UI port interface module) allows you to both view and set those ports’ available modes. All 100Base-TX Fast Ethernet ports can be configured to operate in either standard Ethernet (10 Mbps) or Fast Ethernet (100 Mbps) mode, and in each mode can be

Managing the Module 2-31