![Nortel NT1R20 Скачать руководство пользователя страница 227](http://html1.mh-extra.com/html/nortel/nt1r20/nt1r20_description_1707064227.webp)
NT8D02 Digital Line Card
Page 203 of 290
Line cards
Description
Card interfaces
The digital line card passes voice, data, and signaling over DS-30X loops and
maintenance data over the card LAN link. These interfaces are discussed in
detail in the section “Intelligent peripheral equipment” on page 18.
Digital line interfaces
The digital line interface contains two digital line interface circuits (DLIC).
Each digital line interface circuit provides eight identical and individually
configurable voice and data interfaces to eight digital telephone lines. These
lines carry multiplexed PCM voice, data, and signaling information as time
compression multiplexed (TCM) loops. Each TCM loop can be connected to
a Nortel Networks M2xxx, M3000, or Aries digital telephone set.
The purpose of each digital line interface circuit is to demultiplex data from
the DS-30X Tx channel into eight integrated voice and data bitstreams and
transmit those bitstreams as Bi-Polar Return to Zero, Alternate Mark
Inversion (BPRZ-AMI) data to the eight TCM loops. They also do the
opposite: receive eight BPRZ-AMI bitstreams from the TCM loops and
multiplex them onto the DS-30X Rx channel. The two digital line interface
circuits together perform the multiplexing and demultiplexing functions for
the 16 digital telephone lines.
The digital line interface circuits also contain signaling and control circuits
that establish, supervise, and take down call connections. These circuits work
with the on-card microcontroller to operate the digital line interface circuits
during calls. The circuits receive outgoing call signaling messages from the
CPU and return incoming call status information to the CPU over the DS-30X
network loop.
TCM loop interface circuit
Each digital phone line terminates on the digital line card at a TCM loop
interface circuit. The circuit provides transformer coupling and foreign
voltage protection between the TCM loop and the digital line interface circuit.
It also provides battery voltage for the digital telephone set.
Содержание NT1R20
Страница 2: ......
Страница 4: ...iv 553 3001 105 Standard 5 00 June 1999 iv ...
Страница 12: ...xii Contents 553 3001 105 Standard 5 00 June 1999 ...
Страница 76: ...Page 52 of 290 Description 553 3001 105 Standard 5 00 June 1999 ...
Страница 98: ...Page 74 of 290 NT1R20 Off Premise Station Analog Line Card 553 3001 105 Standard 5 00 June 1999 ...
Страница 154: ...Page 130 of 290 NT5D11 Line side T1 Interface Card 553 3001 105 Standard 5 00 June 1999 ...
Страница 216: ...Page 192 of 290 NT5D33 and NTRB34 Line side E1 Interface Cards 553 3001 105 Standard 5 00 June 1999 ...
Страница 264: ...Page 240 of 290 QPC192 Off Premise Extension OPX Analog Line Card 553 3001 105 Standard 5 00 June 1999 ...
Страница 276: ...Page 252 of 290 QPC452 Basic 500 2500 Analog Line Card 553 3001 105 Standard 5 00 June 1999 ...
Страница 302: ...Page 278 of 290 QPC789 16 port Message Waiting Analog Line Card 553 3001 105 Standard 5 00 June 1999 ...
Страница 306: ...Page 282 of 290 List of terms 553 3001 105 Standard 5 00 June 1999 ...
Страница 314: ...Page 290 of 290 553 3001 105 Standard 5 00 June 1999 ...
Страница 315: ......