# NetworkInterface.T1E1[x].Impedance

Specifies the type of cable connecting a CG 6565 board to the T1 or E1 network.

#### Syntax

NetworkInterface.T1E1[x].Impedance = cable_type

x = 0-(n-1) (0-based trunk number or range of trunk numbers where n equals the number of trunks on the board.)

#### Access

Read/Write

#### Type

String

#### Default

G703_120_OHM

#### Allowed values

DSX1 | G703_120_OHM | G703_75_OHM | HIGH_IMPEDANCE

#### Example

NetworkInterface.T1E1[0..7].Impedance = G703_120_OHM

#### Details

Trunk impedance on the CG 6565 is controlled through a board configuration file. Since trunks are configured in pairs, the configuration setting must be identical for both trunks in a given pair. There are different pairings for a four or eight trunk daughterboard. Trunks are paired as follows:

The following pairings apply to a four trunk daughterboard:

- 0 and 2

- 1 and 3

Valid settings are:

Setting | Description
--- | ---
DSX1 (T1 only) | For DSX1 cables (up to 655 feet - short haul).
G703_75_OHM (E1 only) | For G.703-standard 75 ohm cables.
G703_120_OHM (E1 only) | For G.703-standard 120 ohm cables.
HIGH_IMPEDANCE (T1 or E1) | Reserved for T1 or E1 trunk monitoring applications.

The following pairings apply to an eight trunk daughterboard:

- 0 and 1

- 2 and 3

- 4 and 5

- 6 and 7

Valid settings are:

Setting | Description
--- | ---
DSX1 (T1 only) | For DSX1 cables (up to 655 feet - short haul).
G703_120_OHM (E1 only) | For G.703-standard 120 ohm cables.

Note: To connect an eight-trunk CG 6565 board to a 75-ohm E1 trunk, configure the board as E1 120 ohm and connect a shielded 50-pin Telco cable to a punchdown block or signal entry panel. Then connect the punchdown block or SEP to a 75 ohm BNC SEP or equivalent to convert the impedance from 120 ohm to 75 ohm.

Refer to Configuring the T1 or E1 interface for more information.

#### See also

NetworkInterface.T1E1[x].CRCMFMode, NetworkInterface.T1E1[x].D_Channel, NetworkInterface.T1E1[x].FrameType, NetworkInterface.T1E1[x].Length, NetworkInterface.T1E1[x].LineCode, NetworkInterface.T1E1[x].SignalingType, NetworkInterface.T1E1[x].Type