Sub Rate Data Ports 8-1

SRU Ports Introduction

Chapter 8SRU Ports

8.1 Introduction

This chapter provides information regarding the configuration and troubleshooting for the
Low Delay Subrate Data (LD-SRU) ports.
The SRU ports allow you to connect up to 5 RS-232, low-speed and medium-speed (300 kbps
to 38.4 kbps) data terminals to the Integrated Access System. You can multipl ex a number of
those devices onto a single DS0 time slot of a W AN or OWAN port. Each port has delay that
is a maximum 3ms +/- 10% end-to-end of rates 9.6 kbps or higher for sync, and maximum of
6ms +/-10% end-to-end of rates 9.6 kbps or higher for async.
Each LD-SRU port receives timing from either the external DTE or the Integrated Access
System clock. If the DTE supplies the transmit timing, that cloc k signal mus t be synchr onized
to the Integrated Access System’s clock source.
Note: Some changes to SRU ports require that the ports be put in standby then the active
modes for the changes to take effect.

8.2 SRU port User Screens and Settings

You must configure the SRU port for operation before use. This is done from the SRU port
Main Screen (Figure 8-1). To go to that screen, highlight t he desire d port on th e System Main
Screen and press <Enter>. The SRU port Main Screen has five columns of data for port
configuration purposes. The port numbers on the screen correspond to the port faceplat e jacks.