User guide

52 RealCT Direct API Developer Guide
Chapter 3: T1 Networking
Configuring the Carrier
The carrier parameters determine what framing methods, line
coding methods, and other parameters the board uses to send
and receive data. The parameters you set must match those of
the carrier.
There are several ways to configure carrier parameters.
Configure all channels on a given trunk to use the same values,
using CONFIG_CARRIER. To configure the robbed bit, invert,
or loopback parameters separately for individual channels, use
CONFIG_CHANNEL and RHT_CONFIG_CHANNEL.
However, since there is rarely a need to configure these
parameters separately, we recommend using
CONFIG_CARRIER. To configure only line coding and framing
for all channels on a given trunk, use the Configuration Wizard.
For all parameters, contact your carrier for information about
the appropriate settings.
Configuring the Framing Method
T1 boards support D3/D4 and ESF framing, as described in
Organizing the T1 Data on page 42. Setting the incorrect
framing mode can cause a loss of synchronization, so be sure
your configuration matches your carrier.
Configuring the Line Coding Method
T1 boards support AMI, AMI with ZCS, or AMI with B8ZS line
coding, as described in Organizing the T1 Data on page 42.
Setting the incorrect line coding method can cause bipolar
violations or noise on the line, so be sure your configuration
matches your carrier.