Specifications

ASMi-52CD Ver. 1.0 Introduction E-1
Appendix E
IR-ETH/Q Ethernet Card
E.1 Introduction
IR-ETH/Q is an interface module for RAD modems, used for converting the
Ethernet 10BaseT 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/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
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.
Application
Figure E-1 shows a typical application of the ASMi-52CD module, on which the
IR-ETH/Q is mounted. The LAN connection is made by installing the LRSI-F-14
interface module in the upper section of the LRS-24F hub, or installing the
LRSI-B-14 in the back section of the LRS-24B hub.
ASMi-52
ASMi-52
LRS-24
ASMi-52CD
2-wire
2-wire
RADview
Management
Station
Local Loop
Customer PremisesCentral Office
Figure E-1. Typical Application of ASMi-52CD with IR-ETH/Q