RAD Data comm HCD-E1 Appendix D IR-ETH/Q Interface Module

General D-1
Appendix D
IR-ETH/Q Interface Module
D.1 General
IR-ETH/Q is an interface module for RAD modems, used for converting the
Ethernet 10BaseT electrical levels to the modem TTL levels. It converts the
Ethernet protocol to HDLC to enable long distance transmission and avoid
the Ethernet collision limitation. The IR-ETH/Q module also supports
IEEE 802.1/Q frames.
IR-ETH/Q includes an internal, self-learning Ethernet bridge, which enables
a high performance link between two Ethernet segments at a low
transmission rate. The module also supports VLAN applications. 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 D-1 shows a typical application of HCD-E1 with the IR-ETH/Q
module. Each modem is connected to an Ethernet network via the Ethernet
bridge.
HCD-E1 HCD-E1
Figure D-1 Typical Application of HCD-E1 with IR-ETH/Q Module