Mitel Fax Memo Manual

							12.3 SS7 Integration 
Through its SS7 integration, the Series 6 platform also supports the SS7 out-of-band common 
channeling protocol for data and voice communications between ISDN switches over TlEl 
lines. The SS7 integration terminates the voice channels on 30-channel PCM (El) 
trunks 
(CCITT Rec. G.704). In addition, the SS7 integration provides out-of-band call setup and 
teardown information to the Series 6 platform. The Series 6 system provides native on-board 
SS7 digital support. Centigram’s SS7 integration conforms to CCITT 4.767, Fascicle VI.9 and 
ANSI ISUP standards. 
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							Section 13: Architecture 
The Series 6 platform is a modular, open, standards-based communications server that allows 
users to make, send, receive, and answer voice, fax, and e-mail messages from a single mailbox, 
24 hours a day, by using a touch-tone telephone or a PC. In addition, users can access any 
information service-in any format (voice, text, image )--from the same mailbox. The system 
requires no special environmental conditions, and is compatible with virtually every PBX and 
switching system. 
The Series 6 platform can accommodate from 50 to thousands of users 
economically because of our modular expandable system architecture (MESA) design strategy. 
13.1 The MESA Design Strategy 
Many voice processing companies have product lines with different model’s designed to serve 
specific capacity points. Each system in the product line has to be completely replaced whenever 
a customer outgrows it. At Centigram, we believe that the investments our customers make in 
our products are worth keeping. A basic principle of our MESA design is that our systems can 
be expanded in the field. 
Series 6 systems do not have fixed port/storage configurations. New applications, new 
information formats, new storage and new ports can be added independently. Service bureaus, 
whose subscribers are charged for the amount of time that messages are stored on the disk, 
require a greater ratio of ports to storage hours. Corporate customers, whose employees tend to 
keep messages, typically want more storage. Centigram’s MESA design allows our customers to 
buy only what is needed. All this flexibility is without penalty, since each growth point is 
designed to be cost-effective when compared to competitors’ models that specialize at that 
system size. 
Modular expansion is only one aspect of MESA design. Simplicity, the ability to incorporate the 
latest technology, and distributed processing are integral parts of the Series 6 platform design-a 
design that allows us to build the best systems for today and for the future. 
a Keep ii simple 
The platform is one of the most reliable communications servers in the industry because it is 
engineered to be very simple, with redundancy options that ensure unequaled performance and 
uptime. Each module has only four basic components: the line cards, the CPU, the hard disk 
drive, and the power supply. Our architecture allows us to have Mean Time Between Failures 
(MTBFs) well in excess of five years. 
Use available technology whenever possible 
Series 6 systems are built with commercially available, industry-standard components. We can 
choose the most reliable hard disk drives, power supplies, and chip sets on the market. Our SCSI 
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							hard disk drives, for example, have a minimum of 150,000 hours rated MTBF; field performance 
is far higher. 
The Series 6 system’s design uses an Industry Standard Architecture (ISA) backplane bus, a 
Multi-Vendor Integration Protocol (MVIP) circuit switching bus, and either an Integrated Drive 
Electronics (IDE) or a Small Computer Systems Interface (SCSI) drive hardware interface. 
These cormnon protocols allow our system to accept new technology as it is developed. We have 
been able to add digital networking, interprocessor communications, and important new software 
features to the Series 6 platform by taking advantage of the wide range of ISA-compatible cards 
that can be plugged into our backplane. Improvements in industry standard chips have enabled 
us to reduce the number of chips needed to perform the same functions, which controls costs and 
increases reliability. The recent introduction of large-capacity hard disk drives that meet our 
stringent reliability standards allows us to offer upgrades that double the storage capacity of our 
systems. 
The main processor for each module is either an Intel 80486 or Pentium 100 MHz processor. 
When necessary, we can upgrade to a more powerful processor within the same family, 
Improvements in industry-standard chips also make it possible to incorporate Very Large Scale 
Integration (VLSI) solutions into the Series 6 architecture. Use of the latest technology and 
fewer chips reduce power needs and generate less heat than individual components, which 
increases system reliability. 
The Series 6 platform uses the QNX operating system from Quantum Software. QNX Software 
is a driving member of the Portable Operating System IX (POSIX) committee, which sets the 
standards for hardware-independent operating systems. The QNX software is a 32-bit operating 
system. 
Focus our resources where we 
offer a unique advantage: in sojiktare and architecture 
Using industry standard components and technology allows us to focus our development efforts 
on our unique architecture and software design, leaving component and operating system 
engineering to the companies that specialize in these areas. 
- Centigram has many of the most feature-rich applications on the market today, because our 
standard software package provides millions of distinct classes of service and contains features 
that allow applications to go far beyond simple voice messaging. Also, our high density analog 
line cards and digital connections enable us to add direct DID trunks, TX1 circuits, low-power 
cptions and a multifrequency (MF) signaling option on the line cards. MF allows us to interface 
with cellular telephone networks. 
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							Dktributed Processing 
The Series 6 system’s MESA architecture emphasizes distributed processing for the fastest 
throughput and most efficient use of system resources. Processing occurs at four levels: 
1. Module level 
2. Irma-module communication 
3. Line card level 
4. Disk drive interface 
a At the module level, the main processor controls multiple port configurations. The 
module processor controls trafYic and tracks resource allocati?ns for all internal 
processing interactions. MESA-Link, an internal LAN, integrates 4 Model 640 
modules together at the CPU control level. MESA-Link enables all modules to 
operate as a single system through high-level information exchange and inter-process 
communication (IPC). 
Within a module, the MVIP bus switches calls between cards. This MVIP bus adheres 
to the computer telephony integration (CTI) standard. The MVIP bus connects any 
digital telephony interfaces (such as Tl/El lines) to the DSP cards, where voice 
processing occurs. Service cards (such as fax cards) can be assigned to a dedicated 
port or shared among a group of ports, either analog or digital. 
Many processing tasks are concentrated in the line cards. Each analog or Digital line 
card contains its own 386 processor and multiple digital signaling processors (DSPs). 
The line cards provide: signal processing (speech compression and decompression), 
DTMF detection, pause compression, and MF tone detection. 
In the Model 640 system, the Monitor Control Board II manages multiple SCSI 
interfaces. Each SCSI interface has its own dedicated controller, which manages all 
disk functions and error checking for each hard disk. The Model 120s can contain up 
to four SCSI disk drives which are controlled by a plug-in SCSI card. IDE drivers 
control hard disks in the Model 70 and Model 1201 configurations. 
Centigram’s implementation of distributed processing is unique in the industry. Multiple 
modules in the Model 640 system are linked together with multiple SCSI buses and the 
MESA-Link, an internal LAN. The SCSI disks are reliably managed as a single database. Each 
module processes its own work while having fast, direct access to the common database. 
Database integrity is maintained by a fault tolerant distributed file system. 
A Call Scenario: 
When an outside caller dials the Series 6 VoiceMemo message center number, the call rings on a 
line card port. The line card detects the ringing signal, and relays the event to the module CPU. 
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							The CPU locates the system greeting on the hard disk and transfers the data from the hard disk 
to buffers on the line card. This buffer is divided into three rotating buffers that fill and empty in 
sequence, ensuring that the user never hears a pause in the playback of the greeting. 
The caller enters the mailbox number in response to the system greeting. The line card 
recognizes the DTMF input and sends it to the CPU. The CPU interprets the DTMF tones as a 
mailbox number and locates the personal mailbox greeting on the hard drive. The mailbox 
greeting is transferred from the hard drive to the line card, where it is played to the user. 
When the caller responds to the prompt to record a message for the mailbox, the module 
allocates space on the hard disk drive to store the message, sets up data transfer between the line 
card and the hard disk drive, and drops out. The speech is first digitally sampled by the linecard. 
The line card then compresses this speech and sends it to hard disk drive for storage. This 
compression can be set for 18.3 kbps, 24 kbps or 32 kbps sampling rates. 
4 
When the recipient plays the message, the line card converts the 18.3 kbps, 24 kbps or 32 kbps 
compressed speech data back into 64 Kbits by a reverse algorithm. The-result is expanded to an 
analog signal, which is sent out the line card port to the recipient’s telephone, and the recipient 
hears the message. 
13.2 Functional Overview 
13.2.1 The Series 6 Module 
The Series 6 system is modular. In the Model 640, a maximum of four modules can be 
connected to reach the capacity of a Series 6 system. Thus, when a customer outgrows their 
existing module, they can just add an additional module to it, instead of having to buy a 
completely new system. Each Series 6 module consists of the following 9 components: (See 
Exhibit 13-3 for an architectural diagram of a 4-module Model 640 system). 
l Central Processing Unit 
l Modular Controller Board 
l Backplane 
. MYIP Bus 
l Power Supply 
l Hard Disk 
l Floppy Disk Drive 
l Telephony interface card 
l QNX Operating System 
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							Centrat Processing Unit (CPV) 
The CPU subsystem consists of an80486- or Pentium-based central processor board, with 16-64 
MB of RAM. The board plugs into the ISA backplane. In the Model 70 system, the CPU is on 
the motherboard. Line cards, service cards, and communications cards also plug into the ISA 
backplane, which provides the interface with the CPU. There are 13 ISA-compatible available 
slots for each Model 640 module, 11 available slots in the Model 1201, 10 available slots in the 
Model 12OS, and 7 slots available in the Model 70. 
The backplane accepts many 
ISA-compatible cards, such as fax cards, line cards, DSP cards, communications cards, and 
T l/E 1 interface cards. 
The Model 70 and Model 1201 configurations support the PC/AT IDE interface, while the 
120s and Model 640 systems support the SCSI interface. A plug-in SCSI adapter card is used as 
the disk interface in the Model 120s. All CPU subsystems support the 1.44-MB floppy 
interface. The CPU subsystem includes two serial ports for maintenance purposes. Optionally, a 
second plug-in card will handle several high-speed RS-232 lines for integration with PBXs and 
other peripheral device needs. 
In addition, the Model 640 system uses the Module Control Board II to manage I/O resources. 
MCB II components include: 
0 4 Small Computer System Interface (SCSI) bus interface controllers. 
l External alarm interface 
l Audible alarm system 
0 Four asynchronous RS-232 ports 
0 NW&M 
0 Voltage, temperature, and fan rotation monitors 
Backplane 
I 
Line cards plug into the backplane, which provides the interface between the line cards and the 
CPU board. There are 13 slots for cards in each Model 640 module, 12 slots for cards in the 
Model 1201 and Model 120s systems and 7 slots in the Model 70. 
The backplane is 
ISA-compatible, and accepts many ISA-compatible cards, such as the CPUs, line cards, fax 
cards, Ethernet cards and the serial cards used for RS-232 type integrations and networking. 
M-FTP Bus 
The Multi-Vendor Integration Protocol, (MVIP) CTI standard, bus allows telephony board 
products from different vendors to operator together. The Series 6 platform supports such boards 
as shared resource fax cards, SS7 Protocol cards and DSP cards. 
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							Power Supply Subsystem 
The Model 640 has separate power supplies for the CPU and disk storage subsystems. There are 
two options for both: 
l A 50- to 60-Hz, 1 lo-240 VAC input 500W (nominal), auto-selectable, quadruple- 
output (+5, +12, -12, and -48 VDC) switching power supply plus a 150W disk storage 
module power supply. 
l A -48 VDC input, 500W (nominal), quadruple-output switching power supply (+5, 
+12, -12, -48 VDC) switching power supply plus a 150W disk storage module power 
supply. 
The Model 1201 and Model 120s configurations provide the following single power supply 
options: 
l A 50- to 60-l&, 1 OO- 120 VAC, 500 W 
l A 50- to 60-l&, 200-240 VAC, 500W 
The Model 70 configuration provides the following single power supply options: 
l A 50- to 60-Hz, loo-120 VAC, 200W 
. A 50- to 60-Hz 200-240 VAC, 200W 
Auxiliav Equipment Subsystem 
The auxiliary equipment subsystem can consist of external devices for the Model 640 system 
such as the CSOLIO module for switching to redundant systems resources, automatic 
contact-closure monitoring devices, proprietary PBX or standard signaling integrations, or serial 
interfaces. 
Hard Disk 
s 
Hard disks provide storage for the operating system, system software, mailbox and message 
statistics, and digitized speech. 
Centigram aims for the highest reliability on hard disks, by 
qualifying them through a rigorous burn-in and testing process. Our hard disks must meet a 
minimum MTBF of 150,000 hours. At least two sources are qualified for each hard disk size. 
Floppy Disk Drive 
All Series 6 systems are equipped with a 1.44 Mb formatted (2.0 Mb unformatted) floppy disk 
drive that uses 3.5” double-sided, double density diskettes. The floppy disk drive is used to 
install, reconfigure, and update system software, to back up mailbox and account data files, and 
to upgrade the storage capacity of the hard disk. 
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							Line Cards 
Line cards provide the interface between the Series 6 system and telephone lines from a PBX or 
central office trunk. Line interfaces can be either analog or digital trunks. (See Appendix III for 
a list of line card interfaces supported by the Series 6 platform). The phone line exceptions 
program and the algorithms for digitization and speech compression are stored on the line card. 
Line cards monitor all of the telephony events that occur on the network. The line card runs 
software that interprets events based on the signal pattern that the line card receives. The event 
can be a busy signal, a ring-no-answer, a reorder tone, or a human voice. The program also 
allows the line card to detect silence and pauses. The parameters used to interpret these events 
are based on North American signaling practices. They may need to be adjusted to comply with 
parameters, such as those found in SS7, used in other countries (see Table 4). 
Analog 
A. Direct Inward Dial /DID): The ability for a caller outside a company to call an internal 
extension without having to pass through an operator or attendant. At the Central Office Switch 
The Area Code and Prefix are stripped once the number is identified as a DID telephone number 
assigned to a company. 
B. E&MSignaling: A pair of wires that connect two PBXs or a PBX to a remote extension over 
a voice grade line. The “E” lead or EAR, receives an open or ground signal from the far end and 
the ‘34” lead or MOUTH, transmits a ground or battery condition to the signaling equipment . A 
-48 voltage change on the leads indicates information such as seizure to transmit, recognition of 
seizure, release of circuit, dialed digits, etc. 
Of the 5 types of E&M signaling, Centigram 
supports type I and type II. 
C. Ground start: 
A two wire circuit that uses grounding methods to form connections. A 
momentary grounding on one side of a two wire trunk , usually on the ring conductor, of the tip 
and ring, will establish dialtone. 
A ground start trunk initiates an outgoing trunk seizure by 
applying a maximum of 550 ohms resistance to the tip conductor of the tip and ring. 
Switching 
- 
equipment and telephone circuits must match to operate correctly with each other. 
D. LOO-D Start: A two wire circuit that forms a loop when a station goes off-hook to answer a 
ring event. The ringing event is trigger by the central office sending AC voltage to the ringer of 
a telephone. When the telephone handset is removed from the craddle, a DC loop is formed. 
This action bridges a resistance of the tip and ring, both wires, of a telephone line. 
The central 
office recognizes the DC loop and discontinues the ringing event to the set. 
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							Digital 
-Sianalina: A digital transmission link standard used by the United States, Canada., Hong 
Kong and Japan. A T-l link has 24 channels that operate at 64Kbps each for a total of 1.544 
megabits per second capacity. 
E-1 S@=rling: The European Digital transmission link. An E-l has 30 channels for transmitting 
voice dam at 64Kbps per channel, plus a 64Kbps for signaling and a 64 Kbps channel for framing 
and maintenance. The E-l carries information at a rate of 2.048 megabits per second. 
Line Parameters 
The VoiceMemo application’s console program provides a menu-driven interface for configuring 
line pararneters. Appendix II lists some common phoneline parameters that might need to be 
reconfigured for countries other than the United States. r. 
A silence-detection algorithm in the line card software eliminates pauses at the beginning of, 
during, and after speech recordings and reduces storage requirements. The algorithm identifies 
silence even on a noisy line. If necessary, Automatic Gain Control (AGC) increases the sound 
level of the speech when messages are played back. 
Different types of line exceptions are described below. 
For a list of most used line exceptions, 
see Appendix II. 
Timeout parameters- Line exception timeout parameters help control port usage by 
minimizing the amount of time between call processing events. Each of these line 
exceptions is set to a value that ensures successful completion of the first event, 
without allowing excess time to elapse before the next event begins. 
Incoming signal detection 
-Line card ports use these line exceptions to monitor the 
telephony interface and detect incoming signals. 
Output signaling adjustments 
-These line exceptions control the signaling and tones 
needed to dial out for pagers, message delivery, and off-system messaging 
applications. 
DTMF detection-The Series 6 system receives events in the form of DTMF tones. 
Some aspects of DTMF detection can be customized for individual line card ports. 
Greet command parameters 
-The greet command, used for call progress and line 
signal monitoring, is a general purpose software routine resident on the line card. It 
detects speech, recorded announcements, dead lines, and call-progress tones such as 
ringback, busy, and reorder. When the Series 6 system application software instructs 
a line card port to “wait for a greeting,” 
the greet command uses digital signal 
processors to detect tones and speech. 
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							l Speech and silence detection during recording-These parameters work together to 
detect speech pauses: They stop the system recording when a pause has occurred and 
restart the recording process once speech has resumed. This function can be enabled 
or disabled. 
Serial Ports 
The Series 6 platform supports serial ASCII access for maintenance via any of the serial ports. 
An outboard modem is used for remote maintenance functions and is connected via a serial port. 
The CPU in each model supports two serial ports. The Model 640 has four additional serial ports 
on the MCBII board. The Model 1201, Model 120s and Model 70 need an additional serial card 
to support more than two serial connections. Maintenance normally is performed using either a 
serial VY 100 compatible terminal or a personal computer with VT-100 terminal emulation. 
Up 
to 16 terminals (4 per module on an Model 640) may be connected at one time. 
A terminal is 
connected to serial port one and the outboard modem can be connected to bny of the remaining 
serial ports 
The QNX Operating System 
Centigram’s ability to grow its platform modularly and distribute processing among its 
components is due, in large part, to its operating system. The Series 6 platform uses the QNX 
operating system. QNX has a modular design that can control all system real-time functions and 
applications without the need for outside processors. Operating system functions such as file 
handling, network management, device I/O, and other functions, are performed by a series of 
accessible modules known as server tasks. These tasks communicate with each other through a 
technique known as message passing, where a block of data (the message) is copied from the 
data space of one task to that of another. A microkemel provides synchronization of task 
switching and message passing. QNX switches between tasks many times per second, and the 
switching is controlled by a process called “prioritized event scheduling,” which ensures that the 
most important tasks get CPU processing time when needed. 
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