Franklin Telecom Analog Voice Card
AVC-4 (aka ICV-4)
AVC Specifications:
Data Rate: 64 Kbps
Connectors: 4 - RJ11
Coding: micro-Law / Ampere-Law
Ringer on all 4 loop start ports.
MVIP Compatible Above Board Buss
Industry Standard Architecture (ISA) buss compatible
Summary of Franklin's Analog Voice Card:
Franklin 's Connectivity products incorporate state-of-the-art software and hardware
technologies to allow access to Wide Area Networks, public or private T-1, LAN and
packet switching networks, from a variety of branch office equipment. The Franklin
Branch Node (FBN) is designed to address the management and control of today's
communications needs in remote branch offices.
The Franklin Analog Voice Card is a fully integrated 4 port card with ringer capability. It
supports most digital communications, including PBX & FAX through the Franklin
Branch Node which consists of:
A 4 Port Voice card with ringer and built in
Franklin Above Board Bus (FABB)*
Multi Vendor Integration Protocol (MVIP) Bus.
A T1 card with a built in CSU or DSX interface and built in FABB.
A 64Kbps Clear Channel Card for interfacing the T1 with WAN
with built in FABB.
A Local Area Network card.
* FABB = 8 Megabit (4 Mitel type circuits at 2.048 Mb each).
Voice Connection Module (Model AVC)
Voice is digitized at data rates of 16, 32 or 64 Kbps and transmitted over 1, 2 or 4 DSO
channels of the ICT-1 module respectively. Voice Compression can be selected to offer
u-law or A-law coding for the connection to the North American network or the European
standard. The two-wire analog telephone loop is be configured for loop start signaling.
The AVC provides four 2-wire analog telephone interfaces using industry standard RJ-11
modular jacks in one slot on the PC platform. The board is MVIP Bus compatible.
Configuration of the board is under software control.
Overview Of The Voice System:
The AVC board has several circuits in each voice path which must be initialized for
proper operation. These parameters include PCM operating mode, time-slots internal to
the board, time-slots to be allocated in the MVIP bus selected, and optionally, the
compression mode in use (one common mode for all lines in a particular board), and
the signaling path to be used, and the initial operating mode (standby, on-line, etc.) of the
line and the board address.
The Franklin Above Board Bus (FABB) & MVIP Bus stream is selected by jumpers and
these settings must agree with the specification in the initialization software
configuration.
The AVC board also has capabilities to switch its voice information streams to various
time slots in the stream. Generally, the board is initialized (without compression) to
assign the four ports on the board four contiguous time-slots in the FABB stream (in and
out) selected by jumpers on the board. When compression is active, pairs of ports
share two adjacent time-slots, or in the case of 16 Kbps compression, all share a single
time-slot. The Voice card has ringer capability and built in FABB/MVIP.
THE ICV-4 / AVC VOICE CARD The Franklin Telecom AVC voice board has four
two-wire subscriber line interfaces with audio processing circuitry capable of the
following:
64 kilobit-per-second digital PCM conversion
8-bit code, either A-Law or u-Law
Optional Adaptive Differential Pulse Code Modulation (ADPCM)
compression/decompression at rates of 32 Kbps (CCITT G.721, ANSI T1.301), 24
Kbps (ANSI T1.303) and 16 Kbps (by a proprietary algorithm).
9600 baud FAX compatible either uncompressed or with 32 Kbps compression or
reduced speed at 24 Kbps. Ringer power available on all four loop start circuits.
Compression modes may not be mixed in a single board. All four lines of each Voice
board operate in a single compression mode as selected for that board by PC software
at the time the MVIP/FABB data channels are assigned and the boards are initialized for
operation. Compression rates can be mixed in a PC chassis on a board by board basis.
The resulting 64 Kbps data streams are routed over the MVIP/FABB and, with the use of
Franklin's ICT-1 board, may be sent over one clear channel of a leased T1 1.544 Mbps
telephone circuit, using a corresponding clear channel in the return direction for the
corresponding returned voice traffic in that line. Instead of T1 routing, the data may be
routed back locally in the ABB to another line of the same system, possibly the same
voice card.
When compressed at 32 or 24 Kbps, the voice data from each line is paired with a
second line, and the resulting stream of data is sent as above to a corresponding pair of
voice card lines, either across a T1 line, or to another pair sharing the same PC
platform.
When the voice data is compressed at 16 Kbps, all four lines' data is arranged in one 64
Kbps clear channel and transmitted between two full AVC boards, again either locally or
across a T1 connection.
Each subscriber line interface has off-hook detection, and ring relay to switch
appropriate ringer voltage to the line. Control of the ring relay and monitoring of the
off-hook status are software functions in the PC platform. Tone detection and generation
are not provided in the ICV4.
JP1 and JP2 select one of eight streams of the MVIP bus. JP1 makes the transmit
stream connection, while JP2 makes the corresponding receive connection. These two
jumpers are typically set to the same stream number.
JP3 determines the address of the board on the PC's ISA bus. That ten bit address
always has the most significant bit set, giving a range of possible addresses of 0x200 to
0x3FF. The other bits of address are determined by nine jumpers. |
