6/4/99 13:17 Description A-1
Appendix AEthernet InterfaceA.1 General
This appendix:
• Describes the IR-ETH for RAD modems
• Describes the different IR-ETH connector options
• Lists the Ethernet bridge specifications
• Explains how to install and operate an Ethernet bridge.
A.2 Description
The IR-ETH is an interface module for RAD modems, used for converting the
Ethernet (10BaseT or 10Base2) electrical levels to the modem TTL levels. It
also converts the Ethernet protocol to HDLC to enable long distance
transmission and avoid the Ethernet collision limitation.
The IR-ETH includes an internal, self-learning Ethernet bridge, which enables
a high performance link between two Ethernet segments at a low
transmission rate. The low-speed HDLC transmission is sent over the link
using the modem modulation technique. It is converted back to an Ethernet
signal at the remote modem.
Figure A-1 shows a typical application using an Ethernet interface bridge.
Each modem is connected to an Ethernet network via the Ethernet Interface
bridge.
MODEM MODEM
LINK
Figure A-1 Ethernet Interface Typical Application