AT&T 555-600-736 - Manuals - manualsarea.com

Page 4 - INTRODUCTION TO TRUNKING CONCEPTS; Planning Guides, as well as the Systems Reference Manual.; TIP AND RING EXPLAINED; and the Sleeve called “Ring.”

- 2 - INTRODUCTION TO TRUNKING CONCEPTS The way lines and trunks have been used to meet customers’ needs over past decades is rapidly changing. T-1, ISDN technology, fiber optics, and other advances in telecommunications are forcing us to rethink what lines and trunks should be used for a PBX or Key...

Page 5 - LINES AND TRUNKS

- 3 - LINES AND TRUNKS Telephone lines and telephone trunks are facilities that carry voice or data communications. They are similar in form and function, and the two terms are usually treated as if they are interchangeable. The fundamental difference between a line and a trunk is that a line connec...

Page 6 - OPERATIONS; provides dial tone for an outgoing call.

- 4 - LOOP-START TRUNKS: OPERATIONS Loop-start facilities are the simplest and most common end-user facilities in the nation-wide telephonenetwork. Loop-start facilities provide virtually no supervision between the central office and the customer premises equipment (CPE). For this reason, loop-start...

Page 7 - The Problem of Glare; signaling that a line is being seized.

- 5 - LOOP-START TRUNKS: POTENTIAL-PROBLEMS The most common application for loop-start facilities is single line residential service. Many of the disadvantages of a loop-start trunk in a PBX environment can be inferred from the operation of a loop-startresidential telephone line, like the one you ha...

Page 8 - Automated Attendant Ghost Calls and Loop-Start Facilities; ringing phone and hear dial tone.

- 6 - The ARS feature also isolates the station user from the specific trunk, and even the group of trunks. thatcarries each outgoing call. Other features. such as Callback Queuing (LEGEND) or Busy-to-Idle (System 25) reminders, allow station users to seize trunks moments after a previous conversati...

Page 9 - WHEN TO USE LOOP-START TRUNKS; facilities and when you must use loop-start facilities.; Proper Loop-Start Facility Applications; Some PBXs, especially those that cannot be; Unavoidable Loop-Start Facility Applications; The Centrex is no longer capable of providing efficient internal; facilities are always preferred.

- 7 - LOOP-START TRUNKS: WHEN TO USE LOOP-START TRUNKS There are two times when you consider the use of loop-start facilities: when you should use loop-start facilities and when you must use loop-start facilities. Proper Loop-Start Facility Applications If loop-start facilities are prone to problems...

Page 10 - Cost; loop-start trunks when the key system is replaced by a PBX.

- 8 - Cost Unfortunately, the most common reason for using loop-start trunks is the least valid. This reason is cost. If a customer currently has a key system, service at that location is undoubtedly supplied by loop-start lines. Converting the lines to ground-start trunks may involve a longer insta...

Page 11 - signal when one party disconnects.

- 9 - GROUND-START TRUNKS: OPERATIONS Ground-start facilities were specifically introduced to solve the problems that PBXs encounter on loop-start trunks. A ground-start facility provides an immediate signal when it is seized and it provides a positive signal when one party disconnects. When a groun...

Page 12 - POTENTIAL PROBLEMS; outperform a properly functioning loop-start trunk.; WHEN TO USE GROUND-START TRUNKS; They offer the following major benefits:

- 1 0 - GROUND-START TRUNKS: POTENTIAL PROBLEMS There are very few problems that can occur when properly functioning ground-start trunks serve a properly administered PBX, since modem PBXs and ground-start trunks were literally made for each other. This Application Note does not cover the kinds of p...

Page 13 - OPERATIONAL CHARACTERISTICS; analogy to the residential service in your your home.

-11- DIRECT INWARD DIALING (DID) TRUNKS: OPERATIONAL CHARACTERISTICS Loop-start trunks and ground-start trunks are simple, two-way local facilities, i.e., they can handleincoming and outgoing calls. The operation of loop-start and ground-start trunks can be understood by analogy to the residential s...

Page 14 - DID Trunk Signaling Characteristics; Types of Loop Reverse-Battery Signaling

- 1 2 - Once a trunk has been seized -- the PBX has been alerted to the incoming DID call, and the addressing information has been sent -- there are three possible responses from the PBX. a. The PBX will return an audible ringing signal if the desired voice terminal is available, if the call can be ...

Page 15 - The following are administrable on a trunk basis:

-13- Outpulsing methods, it seizes a trunk by closing the loop and allowing current to flow. When the PBX recognizes the trunk seizure from the CO it responds by reversing the battery and ground on the Tip andRing leads. On delay-dial trunks this signal is called the delay-dial signal. On wink-start...

Page 16 - CONSIDERATIONS IN USING DID TRUNKS

The options for each trunk group are as follows: * DID Trunk Protocol *Wink start (default) -14- ● immediate start * Dial Mode * pulse (default) ● tone * Expected Number of Digits * 3 (default) *0 to 4 * Number of Digits to Add * 0 (default) * 0 to 4 CONSIDERATIONS IN USING DID TRUNKS DID trunks are...

Page 17 - WHEN TO USE DID TRUNKS; options of the LEGEND system.; Simple Tie Trunk Operation; interchangeably. This type of facility links two PBXs.

-15- WHEN TO USE DID TRUNKS DID trunks provide fast access to specific individuals. DID trunks should be considered when a customerhas sales people who work with assigned territories, service people who work with ‘assigned accounts, or any other organization seeking personal accountability. DID trun...

Page 18 - Tandem Tie Trunk Operation; talk to an outside supplier in the Los Angeles area.

-16- (There will be some Of course, these tieordinary tie trunks. In special cases, tie trunks are used to join one PBX directly to another PBX. This may occur if multiplePBXs serve a single-customer at a single location. A typical example would be a corporate headquarters consisting of several buil...

Page 19 - when the trunk group is administered, and is usually the attendant.

- 1 7 - TIE LINES: Transferring Calls The MERLIN LEGEND CS supports trunk calls that come into the system and go out on another trunk without any operator assistance. However, the transmission code in the system does not permit multiplehops, and there is no automatic routing system which can be used...

Page 20 - The transmit and control signals for each signaling type are:

-18- In order to approach a.LEGEND system implementation with tie trunks it is really only necessary to knowwhich signaling formats are supported and to determine which of these supported formats are required. TheLEGEND system with the 400EM module supports Type 1 E&M Standard, Type 1 E&M Co...

Page 21 - OFF PREMISES STATIONS

-19- OFF PREMISES STATIONS On occasion, customers need to locate telephones away from the principal area of the PBX or Key system terminal concentration. The telephone can use an off-premises or out-of-building arrangement. There is amajor difference between the two types. An off-premises telephone ...

Page 22 - System Reference Manual.

- 2 0 - When an Off-Premises telephone is connected to the LEGEND system via the 008 OPT module certain accessories must be used for grounding and protecting the system from power surges, electromagnetic interferences, and electrostatic discharges. These components are specified in Section 5 of the ...

Page 23 - OVERVIEW AND OPERATIONS; Communications System interfaces with ISDN-PRI.

-21- T-1 (DS1) SERVICE OVERVIEW AND OPERATIONS The goal of the T-1 (DS1) section is to present basic information about T- 1 networking, what it is, how itoperates, and what it means to the customer. The section does not explain how the MERLIN LEGEND Communications System interfaces with ISDN-PRI. Fu...

Page 24 - Potential Problems/Limitations

- 2 2 - service, quickly and efficiently. In the past it was necessary to establish a new circuit for virtually every application a customer wished touse. Whether it was teleconferencing, facsimile, hifi audio, video, or computer transmissions, generally a new line or trunk had to be run. It require...

Page 25 - DATA COMMUNICATIONS EQUIPMENT; channels are not a primary concern.

-23- The technology for T-1 is moving rapidly. The encoding system and components are not always upgradable to the newer innovations. ● If the customer application requires maximum network reliability, automatic dialing back-up in case of digital facility failure could prove costly. Do GBS Customers...

Page 26 - and transmits them to the DTE. The CSU has three primary uses:

- 2 4 - CHANNEL SERVICE UNIT (CSU) The Channel Service Unit (CSU) provides the interface between the 100D module and the DS1 facilities. T WO AT&T models are available for use on the Legend system: the ESF T1 CSU and the 551 T1 L1 CSU. ● Model 551-T1L1 Reg. Number G1 47226819-/DE-N The 551 T1 CS...

Page 28 - DS1 FACILITY SERVICES

- 2 6 - The following table identities the AT&T DS1 services available to customers. DS1 FACILITY SERVICES Digital Signal 1 Service Description ISDN T-1 Megacom (Megacom An outgoing x x WATS) Service domestic long- distance service used in place of WATS service. Megacom 800 Service An incoming, ...

Page 30 - ISDN

-28- Digital Signal 1 Service Station Number Identification/Automatic Number Identification(SID/ANI) Service Description A caller identification service f o r s y s t e m s w i t h display telephones, call report systems, etc. * * S I D a l l o w s t h e called s t a t i o n t o d i s p l a y t h e ...

Page 31 - SPECIAL HOTEL/MOTEL TRUNKS; OPERATION OVERVIEW; each time a guest makes a call.; MAINTENANCE AND TROUBLESHOOTING; reference guide to use when difficulty occurs.

-29- SPECIAL HOTEL/MOTEL TRUNKS OPERATION OVERVIEW In certain areas of the country there are special trunks for hotels and motels about which you should be aware. At one time they were widely used but today they are found generally in rural areas. The trunksgenerally are called HOBIC lines by teleph...

Page 32 - HARDWARE

- 3 0 - HARDWARE The Legend system hardware most directly connected with Lines/Trunks are the Control Unit Modules. The specifications for each module are presented later in this section. Also the system uses different types of lines/trunks for the different individual functions of each operating mo...

Page 36 - 91A Power supply module

-34- This section lists the LEGEND system trunk and off-premises modules and the appropriate PEC andComcodes. More complete code information can be found in Section A of the Systems Manual (555 -610- 200). Line/Station Modules PEC Comcode 100D DS1 module 61491 105461560 400 E&M module 400 GS/LS/...

Page 37 - ADMINISTRATION; appropriate forms to the NSAC.; CONSIDERATIONS; setting for the disconnect signal from the CO.

-35- ADMINISTRATION To properly administer a MERLIN LEGEND system at the time of initialization requires that care be takenduring the planning phase of the sales activity. This is especially true if the system is to connect to a number of different trunks and lines, such as DID, Tie, or ISDN. in add...

Page 38 - R E F E R E N C E S

- 3 6 - R E F E R E N C E S GBS SCAN Competitive Newsletter, “Everything You Need to Know About ISDN”, Nov/Dec 1988. MERLIN LEGEND Key System Planning Manual (555-610-112) MERLIN LEGEND PBX System Planning Manual (555-610-113) MERLIN LEGEND Data Guide (555-610- 114), Chapter 2 MERLIN LEGEND System R...