User guide

78 RealCT Direct API Developer Guide
Chapter 3: T1 Networking
Testing the Application
There are four basic ways of testing your application:
Using AccuSpan
Placing calls over a live T1 line
Using a T1 simulator
Connecting trunks A and B
Using AccuSpan
AccuSpan is the best way to test the overall robustness and
fault tolerance of your system. AccuSpan is a DOS-based utility
that gives you full control over the carrier configuration, alarms,
and bit patterns sent and received. It can also receive or
generate calls. By changing the carrier parameters, you can test
different scenarios for your application. For example, you can
see what kinds of errors you receive if you configure your
application to use ESF framing and the CO uses D3/D4. You can
also transmit alarm conditions to see how the remote end
responds. To use AccuSpan, connect two back to back computers
with one running the application and the other running
AccuSpan.
The most powerful feature that AccuSpan provides is signaling
mode. In signaling mode you can transmit any possible bit
pattern to the application, where the received bit pattern is
always shown on screen. By sending certain bit patterns at
specific times, you can manually generate all events the protocol
supports, such as line seizure, answer, or disconnect. You can
then send valid events at invalid times, send invalid bit
patterns at several different states of the call progress, or send
signals that are too long or too short and check how the
application responds. Using signaling mode requires a good
understanding of the protocols. If you are not already familiar
with the protocols, view the bit patterns sent or received on the
line during normal operation to see how the protocol operates.
Appendix A, T1 Line Protocols, on page 223, also provides
information about bit patterns used in the line protocols.