Nortel Networks 553-3001-211 manual E1 interface circuit, Signaling and control

Page 246 of 894 NT5D33 and NT5D34 Lineside E1 Interface cards

E1 interface circuit

The LEI contains one E1 line-interface circuit which provides 30 individually configurable voice interfaces to one E1 link in 30 different time slots. The circuit demultiplexes the 2.56 Mbps DS-30X transmit signaling bitstreams from the DS-30X network loop and converts it into 2.048 mHz E1 transmit signaling bitstreams onto the E1 link. It also does the opposite, receiving receive signaling bitstreams from the E1 link and transmitting receive signaling bitstreams onto the DS-30X network loop.

The E1 interface circuit provides the following:

•An industry standard CEPT (0 to 655 feet) interface

•DS-30X signaling protocol into FXO A- and B-channel-associated signaling protocol

•Switch-selectable transmission and reception of E1 signaling messages over an E1 link in either loop or ground start mode

•Switch-selectable call processing between the Australian P2, North American Standard, or other user-configurable schemes

Signaling and control

The LEI also contains signaling and control circuits that establish, supervise, and take down call connections. These circuits work with the system controller to operate the E1 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.

Card control functions

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

Microcontrollers

The LEI 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 CP through the card LAN link

553-3001-211 Standard 2.00 September 2004