Nortel Networks Circuit Card User Manual

 NT5D11 and NT5D14 Lineside T1 Interface cards

The lineside T1 card passes voice and signaling data over DS-30X loops 
through the DS-30X Interfaces circuits and maintenance data over the card 
LAN link. 

The lineside T1 card contains one T1 line interface circuit which provides 24 
individually configurable voice interfaces to one T1 link in 24 different time 
slots. The circuit demultiplexes the 2.56 Mbps DS-30X Tx signaling 
bitstreams from the DS-30X network loop and converts it into 1.544 mHz T1 
Tx signaling bitstreams onto the T1 link. It also does the opposite, receiving 
Rx signaling bitstreams from the T1 link and transmitting Rx signaling 
bitstreams onto the DS-30X network loop.

The T1 interface circuit performs the following:

•

Provides an industry standard DSX-1 (0 to 655 ft./200 meters) interface.

•

Converts DS-30X signaling protocol into FXO A and B robbed bit 
signaling protocol.

•

Provides switch-selectable transmission and reception of T1 signaling 
messages over a T1 link in either loop or ground start mode.

The lineside T1 card also contains signaling and control circuits that 
establish, supervise, and take down call connections. These circuits work 
with the system controller to operate the T1 line interface circuit during calls. 
The circuits receive outgoing call signaling messages from the controller and 
return incoming call status information to the controller over the DS-30X 
network loop.

Control functions are provided by a microcontroller and a Card LAN link on 
the lineside T1 card. A sanity timer is provided to automatically reset the card 
if the microcontroller stops functioning for any reason.