# Configuring the T1 or E1 interface

This topic describes how to configure the board for E1 or T1 trunks for the following types of configurations:

- No trunk configuration

- T1/E1 120 ohm configuration

- E1 75 ohm configuration

For examples, refer to Sample T1 trunk configuration or Sample E1 trunk configuration.

## Board configurations with no trunks

If your system configuration does not use T1 or E1 trunks, set the NetworkInterface.T1E1[x].Type keyword as follows:

NetworkInterface.T1E1[0..15].Type = NONE

## T1/E1 120 ohm configuration

The CG 6565C board has been shipped to you configured as a T1/E1 120 ohm board. There are no hardware changes required for the T1/E1 120 ohm configuration. Use the software to set the board configuration by performing the following steps:

Step | Action
1 | Set the NetworkInterface.T1E1[x].Type keyword in the board keyword file to T1 or E1. You must specify all trunks that are being used as either T1 or E1. Do not specify more than one trunk type per board. Specify unused trunks as NONE.
2 | Set the NetworkInterface.T1E1[x].Impedance keyword to DSX1 (for T1) or G703_120_OHM (for E1).
3 | Set the NetworkInterface.T1E1[x].FrameType, NetworkInterface.T1E1[x].LineCode, and NetworkInterface.T1E1[x].SignalingType keywords to values appropriate for your configuration.
4 | Ensure that you use the correct cables. Refer to Connecting to an E1 network or to Connecting to a T1 network.

## E1 75 ohm configuration

To connect a CG 6565C board to a 75-ohm E1 trunk, configure the board as E1 120 ohm, and use a signal entry panel (SEP) or equivalent to convert the output drive and source impedance to the 75-ohm standard.

## Sample T1 trunk configuration

The following example shows a sample T1 configuration for 16 trunks:

NetworkInterface.T1E1[0..15].Type = T1
NetworkInterface.T1E1[0..15].Impedance = DSX1
NetworkInterface.T1E1[0..15].LineCode = B8ZS [other values possible]
NetworkInterface.T1E1[0..15].FrameType = ESF [other values possible]
NetworkInterface.T1E1[0..15].SignalingType = CAS [other values possible]
DSP.C5x[0..95].XLaw = MU_LAW
DSPStream.VoiceIdleCode[0..15] = 0x7F
DSPStream.SignalIdleCode[0..15] = 0x00

## Sample E1 trunk configuration

The following example shows a sample E1 configuration for 16 trunks:

NetworkInterface.T1E1[0..15].Type = E1
NetworkInterface.T1E1[0..15].Impedance = G703_120_OHM
NetworkInterface.T1E1[0..15].LineCode = HDB3 [other values possible]
NetworkInterface.T1E1[0..15].FrameType = CEPT
NetworkInterface.T1E1[0..15].SignalingType = CAS [other values possible]
DSP.C5x[0..95].XLaw = A_LAW
DSPStream.VoiceIdleCode[0..15] = 0xD5
DSPStream.SignalIdleCode[0..15] = 0x09

Note: The syntax [0..15] specifies that the configuration supports any valid number of trunks within the range of 0 through 15 trunks.