==Phrack Inc.== Volume One, Issue Eight, Phile #3 of 9 ^ ^/ + \ / + \%PLP%>>>>>>>>>>>>>>>>>>PLP<<<<<<<<<<<<<<<<<<%PLP%%---% %---%% P % The Executioner % P %% h % % h %% a % and the % a %% n % % n %% t % PhoneLine Phantoms! % t %% o % - - - % o %% m % % m %% s % Present: The City Wide Centrex % s %%---% %---%[PLP]>>>>>>>>>>>>>>>>>>PLP<<<<<<<<<<<<<<<<<<[PLP] The CWC (City-Wide Centrex) feature provides multiple location largebusiness customers with centrex features, attendant features, and dialingcapabilities that are transparent across geographic locations and areindependent of the configuration of the #1AESS switches providing the service.Historically, centrex customers have been somewhat limited to the bounds of theservicing switch. Customers could be built across switches, but withlimitations. Multiple locations could be arranged to share some features incommon only when placed in a centrex complex served by a single switch.Obviously, for this to be feasible, the locations had to be geographically neareach other. The CWC feature expands the concept of the centrex group byallowing a multi-located business to function as a single centrex arrangementcalled a CWC group. Although each customer location remains a part of its ownswitch with its own individual capabilities, it now functions as part of theCWC group. Selected centrex features that were defined to operate within thebounds of a serving switch centrex group are now redefined to operate withinthe bounds of the CWC group. The outer boundary of the CWC cannot exceed theboundary of the LATA due to LCCIS constraints. The CWC feature provides a comprehensive communications package for amultiple location centrex customer. Some advantages are: o Extension to Extension (Intercom) dialing. o Concentration of private facilities access at one location. o Elimination of dedicated facilities between locations within the CWC group. o Transparency of feature operation across switches.Use of CCIS trunks to replace tie trunks results in the need for fewer totaltrunks and trunk groups. Remote access reduces the total number of customertrunks required and centralizes customer facilities at one location. Allswitches need LCCIS so that information can be passed between locations.===================Intercom Dialing=================== Intercom dialing gives the customer the ability to dial extension numbers(intercom) to other locations. This is done either by dialing the interlocationintercom number or by a speed call code which contains an interlocationintercom number. The customer has the option of routing these interlocationintercom calls via simulated private or public facilities. After determiningthe intercom number dialed is in location, the originating office routes thecall to that location. The call is identified in the centrex customer's digitinterpreter tables as an interlocation intercom call and normal interofficecall processing determines routing. A decision is made as to whether simulatedfacilities are used for routing the call based on the location identificationof the called line. If needed, a simulated facility is seized. This isdetermined by a distant line status request on the called line at the end ofdialing. The originating offices sends information to the terminating officeidentifying the call as interlocation intercom call. The CWC group andlocation identifier of the calling party are also sent. This is done by usingthe RCLDN (retrieval of calling line directory number) to transmit thisinformation. The terminating office recognizes as incoming call as such. If thetwo-way simulated private facilities are used, the count on facilities at theterminating office is incremented. The use of 2 way simulated pricatefacilities for a call is based on the location identifier of the calling lineand whether simulated private facilities were used on the outgoing side.============================Centrex Attendant Console============================ The tie trunks are replaced by CCIS trunks, therefore some changes arerequired in the use of the attendant console. The changes are as follows: o Busy Verification and attendant call through tests are not applicable since there will no longer be specific trunks dedicated to the customer. o The existing trunk group busy lamps are replaced with busy lamps for the simulated facilities between locations. The digit interpreter table entry at each remote location contains the"Dial 0" DN for the attendant. This is done to process interlocation intercomcalls which terminate to the attendant. If the attendant console uses a centrexdata link, the line equipment assigned to the DN should specify the callindicator lamp to be used. A different DN should be used for each location ifseparate call indicator lamps are desired for calls from each location. Thiscall indicator lamp flashes at the intragroup rate of 120ipm (interruptions perminute) to indicate interlocation intercom calls. The RCLDN primitive is used to transmit information for intercom dialingbetween locations. In addition, the RDLS priminitive is used to provide CWCinformation to obtain the CWC group and location identifier of the called line.The originating, incoming, and CCIS incoming registers are used to saveinformation at both he originating and terminating offices. These registersinclude the CWC group, CWC location identifier, a CWC call type, and anindicator whether simulated facilities were used at the originating.===========================Remote Access to Private== Facilities =========================== Remote access to private facilities allows the CWC customer to accessphysical private trunks and simulated facilities at a single location. Thisallows customers to consolidate their private facilities at one location. Thenumber of trunks required is reduced. Any station can access these facilitiesby dialing the same access code as the main location. If a station dials theaccess code for a private facility, the call is routed to the main locationusing the same facility as an interlocation intercom call. It is then routedout from the main location. The CWC feature does not allow the customer to usethe ACOF (Attendant Control of facilities) feature from a remote location. Thetypes of private facilities which are accessible are: o Tie Trunks o FX (Foreign Exchange) o CCSA (Commmon Control switching arrangement) o ETS (Electronic Tandem Switching) o WATS (Wide Area Telecommunications system) o FRS (Flexible Route selection) o EEDP (expanded electronic tandem switching dialing plan) The CCIS direct signalling messages are used to communicate between theremote and main locations during the digit collection and analysis of out-goingcalls. Once the voice path has been established, a CCIS banded signallingmessage transmits the digits collected. A remote access register is used tostore information retrieved during the processing of the signal requests. Thisregister belongs to the OR (Originating Register) pool at the main location. The remote location is responsible for digit collection and transmissionof collected digits. A remote access data CCIS direct signalling messagetransmits the digits from the remote to the main location, which returnsinstructions for the next action to be performed. The following items are sentfrom the remote to the main location: o The digits collected. o The FRL(facility restriction level) of orig. line. o A FRL present indicator o A customer changeable speed call indicator. o A call forwarding over private facilities indic. o An add-on indicator. o The CC location identifier of remote location. o The remote access register # of the main location. o An abandon remote access request indicator. The main location analyzes the information transmitted and returns thenext set of instructions to the remote location. The full analysis of a callmay require several direct signalling messages with information saved from theprevious direct signalling messages. This is required to process the currentdirect signalling message being saved in the remote register. The informationgathered is used to establish the voice path for the call. Upon receipt of adirect signalling request, processing is done in accordance with the functionindicated in the remote register. The types are as follows: o Translate access code o Translate prefix digit o "1+" dialing check o Check for possible account code o Complete account code received o 3 digit translation o 6 digit translation o 10 digit translation o Analyze authorization code o FRS 3 Digit translation o CCSA translation o Abandon call After processing at the main location is complete, the remote accessregister is set up to identify the next type of function. Then, the mainlocation returns a CCIS remote message to the remote location. The informationreturned from the main location is always in the same format and is saved onthe OR.===========Features=========== The CWC group is allowed many features, here is a list of them.1. Call Forwarding Variable: Users can forward their calls to remote stations located in another office by dialing the access code and the intercom number of the CWC station.2. Call Forwarding Busy Line: Provides for the forwarding of calls to any interlocation station within the CWC group upon encountering a busy station.3. Call Forwarding Don't Answer: Provides for the forwarding of calls that are not answered within a predetermined number of ringing cycles.4. Call Transfer: Allows the station user to transfer any established call to any other station within the CWC group with the following constraints. o Dropback rules do not permit 2 outgoing trunks to be involved in the final 2 party connection. However, 2 outgoing trunks can be involved in a 3 way conversation. o On interoffice calls involving a fully restricted station, flash capability is allowed. However, the controller is not permitted to connect the fully-restricted station to any other station, either in dropback or a 3 way conversation. Cross network call transfer transparency requires that each location beprovided the Call Transfer-Individual or Call Transfer-Individual-All callsfeature. The CTO (call transfer outside) option may be provided.5. Call Waiting feature provides a burst of tone when the called party is busyon another call. The types of Call Waiting features and CWC interactions are: o Call Waiting Originating: allows a CWC calling station to direct a call waiting tone toward a busy station within the same CWC group. o Call Waiting Intragroup: gives call waiting tone to a called party which has call waiting terminating on all intragroup calls. o Dial Call Waiting: Allows originating CWC station users to invoke call waiting on CWC intragroup calls by dialing an access code followed by the extension number of the station to be call waited.6. Distinctive Ringing/CW Tone: Allows a CWC station user to determine thesource of a call incoming to the station. This is done by associating adistinctive ringing or tone pattern with the incoming call based on its source.Interlocation CWC calls receive intragroup treatment.7. Message Desk Service: Provides centralized and personalized call coverage ormessage answering capabilities which can serve the needs of all CWC locations.The Call Forwarding Variable and Call Forwarding Busy Line/Don't Answer featureare needed of forwarding calls from stations within the CWC group.8. LASS (Local Area Signalling Service): Provides the called party with callmanagement and security services. Local CCIS is required for multiple-officegrouping within a LATA for intercom calls. The following features comprise theLASS offering : o Automatic Recall: Enables a station user to place a call to the LCDN (Last Call Directory Number) currently associated with the users fone. The LCDN can either be the last party called by the station user or the last party to call the station user. o Distinctive Alerting: Allows the station user to prespecify a set of numbers which activate a distinctive ring or distinctive call waiting tone. The CWC extension numbers can be entered on the screen list. When the user receives a call from one of these numbers, the phone if idle, will ring with a special distinctive ringing pattern. If a call waiting customer's line is busy, a special tone notifies the customer of the impending call. o ICLID: provides the number which is calling the station user. (Explained in other files) o Selective Call Forwarding: (Explained in other file) o Selective Call Rejection: Provides the user with the capability of not being alerted by calls from a specified set of numbers. The user inputs the numbers to be rejected from the station set. These numbers are specified either directly (dialed in) or as the number of the last call received. The CWC extensions are allowed on the screen list.============================================================(C) 1986 The Executioner and The Egyptian Lover and PLP ============================================================This file is based on the AT&T document for the CWC.
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