Line Interface Units; Signaling And Control; Card Control Functions; Microcontroller - Avaya Nortel Communication Server 1000 Reference

NT1R20 Off-Premise Station Analog Line card

Line interface units

The NT1R20 OPS analog line card contains eight independently configurable interface units.
Relays are provided in each unit to apply ringing onto the line. Signal detection circuits monitor
on-hook/off-hook signaling. Two codecs are provided for performing Analog/Digital (A/D) and
Digital/Analog (D/A) conversion of analog voiceband signals to digital PCM signals.
Each codec supports four interface units and contains switchable pads for control of
transmission loss on a per unit basis. The following features are common to all units on the
card:
• OPS or ONS service configurable on a per unit basis
• terminating impedance (600 or 900 ohms) selectable on a per unit basis
• standard or complex balance impedance (600 or 900 ohms, 3COM1 or 3COM2)
selectable on a per unit basis
• loopback of PCM signals over DS-30X network loop for diagnostic purposes

Signaling and control

This portion of the card provides circuits that establish, supervise, and take down call
connections. These circuits work with the CPU to operate line interface circuits during calls.
The circuits receive outgoing call signaling messages from the CPU and return incoming call
status information over the DS-30X network loop.

Card control functions

Control functions are provided by a microcontroller, a card LAN interface, and signaling and
control circuits on the NT1R20 OPS analog line card.

Microcontroller

The OPS analog line card contains a microcontroller that controls the internal operation of the
card and the serial card LAN link to the controller card. The microcontroller controls the
following:
• reporting to the CE CPU through the card LAN link:
- card identification (card type, vintage, and serial number)
- firmware version
- self-test status
122 Circuit Card Reference
Comments? infodev@avaya.com
July 2011