3,143,601 9 intercept office equipmeit proceeds from o-utpulser 130 on a multifrequency basis, the directory number identity bein.- registered in regl'ster 93. Should identifier 120 fail for aiay reason to identify the caued directory number, an information digit indicat- 5 ing this is registered in outpulser 130 in the same manner as when identifier 120 fails to identify a cauing line directoiy num@ ber. In this instance onlv the information digit is transmitted to the intercept o@ice to call in an intercept operator who must request the number dialed by 10 the cahing party. Upon complet@on of the transmission to the intercept office outpulser 130 releases and outpulser link circuit 140 disconnects from intercept trunk 50. Release of outpulser 130 renoves the ground fro.7n lead AB, thereby 15 releas-in.- relay MF and restorin.- the connect,'@on throu-,h front contacts TT(5) betnveen ring and tip busses 15 and 16 and the intercept office throigh trunk finder switch T-F and outgoing intercept trunk circuit $0. Tne release of relay Nff completes a circuit from ground through back 20 contact NIF(7) thereof, front contact MFI(2) and the winding of relay TT to battery. Relay TT operates in this circuit and locks throu-h its own front contact T--P(7), conductor 17 and contact ITR(L) to ground. The transmission path forward from trunk 50 through trunk finder 25 switch Tk- is maintained, upon the release of outpulser 130 and relay AIF, by a direct-current circuit bridging the tip and rin- connections to terrrinals 78. This circuit may be trace'd through back contacts MF (11) and MF (3), front contact MFI(L) and inductor 58. V,/hen relay TT op- 30 erates, an alternate maintaining circuit is completed through front contact TT(5) in parallel with the abovementioned front contact of relay LMFI. The circuit through the front contact of relay TT maintains the transniission path forward to the intercedt office until the call- @ 5 in.- party disconnects. Operation of relay TT disconnects the locking circuits for relays RRI and ITP-1, thereby releasing the lock;ng circuits for relays SP and MFI. Release of relay !TR-1 opens contact I-,, R(l) tra-@isfer-ring the holdin.- ground 40 for relay TT to the sleeve lead holdin.- ground in connector switea L'-. This circ-,iit may be traced from battery throu,@h the winding o-f relay TT, front contact T-i (7), co,-iductor '7, back contact !TR-1(1), conductor P4, sleeve lead terminal of ter@ninals 10, contact K, in- 45 ductor 7 to ground. -.Oelay TT, therefore, remains ener,-@ed under control of the calling pqrty. VAen the callin- party disco-riiiects, contact K opens to release relay TT. lih.- appeara-iice of the sleeve lead holding @round on busy conductor 17, as above-traced, also maintains ir,- 50 tercept trunk 50 in the busy condition for the duration of 'che cail. When relay TT operates upo-n the release of the iden tificat-lon apparatus, front co-@itacts T-L (2) and TT(4) thereof complete the transmission path from the callin r5 pai:',y to the intercept o@-lice. This circuit is comple@ed from the ring and tip tenninals of connector switch terminals 10, ttirou.-h coriductors 12 and 13, windings of relay IT@R-1, rir,,- and tip busses 15 and 16, front contacts i-T(2) and TT(4), capacitors 35, back contacts MF(l) 60 and MF(3), terminals 78 of tr-,ink fmder switch TF, and outgoing intercept trunk circuit '00 to the intercept office. Closure of this set of frori@L contacts of relay TT al. 10 con.nects diode 30 across the rin.- and tip busses 15 and iL6 to trip ringing without providin.- a direct-cu-rrent super- 5 visory path. This prevents the callin.- party from being charged 'Lor the call. the For tl-@-- above description it was assumed that called directory number corresponded to a single-party line, or to a rLTi.@ party on a two-party line. It will be i-O evident, however, that the operation of the present circuit is substantially similar to that described above where theintercepted caU is to a directory nurnber correspondin.@ to a tip parly, exce-pt that relays TR and TRI are operated rather than relays RR and RRI. Thus, a tip 75 10 party indication is provided to the outpulser over lead T when relay TRI operates to connect ground to lead T through front contact TRI(3) and back contact SP(3). V@'hat has been described herein, therefore, is a siinple and econoinical intercept circuit arran.-ement which is operative in conjunction wilh existing number identification circuilry at the local office to automatically identify the directory number of an intercepted call and to transmit the ider-itified number to a central intercept office. It is to be utiderstood, however, that the particular arrangements describ-.d above are merely illustrative of the application of the principles of my invention. Numerous other arrangements may be devised by those skilled in the art without departing from the spirit and scope of the invention. What is clai.-ned is: 1. A telephone switchin- system comprising a local o!%ce including a calling line and a called line each havin.- distinct directory numbers, identification equipm. ent at sa;d local office operative to identify the directory number of said callin.@ line, switching means responsive to the directory number of said called line for establishi-ig co-@inen-tiC>ps to sa;d called line, nieans for intercepting calls to said called line, an-I means under control of said :@ntereepting means for op@-rating said identification equipmeint to idertify the directory number of said called line instead of said callir@g line. 2. A telephone switching system in accordance with claim 1 further comprising an intercept operator trunk and means for transi'erring said called line directory number to said incereept operator 'Lrunk. 3. A te!et)hone sys,em iii accordance with claim 2 further cor-nprising swilehing means under control of said identific . ation eqdipment and said interce_t)ting means for connecting said cared line to said intercept operator trunk. 4. A telei)hone sw;tchi-.ig system comprising a local office, a plurality of lines at said local office each having a corresponding directory number, identifying equipment at said local ofece including translator means and means responsive to a call from a calling one of said lines for connecting said translator means to said calling line to 'dent@fy the directory number thereof, an intercept office, means for intercepting calls to a called one of said lines at said local office, means coupled to said intercepting means and operative incident to the interception of a call for connecting said identifying equipment to said called line, mea-iis for operating said translator means to identify the dircelory number of said called line instead of the directory number of a calling line, means operated by said tr,,nsiator means for re,-istering iden@ified directory number's, and means for transmitting said called line dire.-tory ndmbers only to said intercept office. 5. A telephone switching system comprising a pluralioj of subscriber 1-ines having individual directory number desig ations, some o@j' sdd subscriber lines being unavailable for use, means for re,-istering directory number designations, number network and identifier means associated with said subscriber lines and operative to selectively provide said individual directory nurnber desianations to said reg:stering means, intercept trunk means including means fo'r detectin.- a call to one of said unavailable subscriber lines, means responsive to said detecting means for operating said number network and identifier m.-ans, th-- operation tuereof providing the individual directory ni,-@nber designation of said one unavailable subscriber line to said registering means, a called line directory nun-iber register, and means operative in conjunction with said intercept trunk means for transferring the directory number designation of said one unavailable line from said registering means to said called line directory number re-,ister. 6. A telephone switching system including a local office having a plurality of lines assigned distinctive directory numbers, identifying equipment at said local office, first circuit means for connecting said identifying equipment to

a calling one of said lines to identify the directory number of said calling lines, and means for intercepting calls to prede.termined ones of said lines, said switching system being characterized by @econd circuit means connecting said intercepting means to said identifying equiprnent in response to a call to one of said predetermined lines, and means including said identifying equipment operative incident to the connection fnereto of said intercepting means for identifying the directory number of said one of said predetermined lines instead of a calling one of said lines. 7. A telp-phore switching system in accordance with claim 6 being further characterized by an intercept offic@e ,and means for transmitting the directory number of said one predetermined line to said int6rcept office. 8. A telephone switchirig system in accordance with claim 6 being further characterized by said first and second circuit means being in a mutual lockout relationship. 9. In a telephone switching system, -the combination comprising a calling line and a called line, said called line being unavailable for receiving caus, line number identification equipment located at the same office as said called line, means under the control of said line number identification equipment for outpulsing identified line ntimbers, an intercept position including means to record called line numbers, means for interceptin@. calls to sp-id called line, means operated by said intercepting means for connecting said called line with said line number identification equipment, means for operating said line number identification equipment to identify the number of said called line and to provide said caued line number to said outpulsing means, means operated by said interceptin,@ means for connecting said registerin@ means in said intercept office with said outpulsing means, and means operative after the outpulsing of said called line number to said registering means for interconnecting said intercept office and said callidg line, said interconnection being maintained under the control of said calling line. 10. A tolephon-. switching system comprising a local office, a plurality of line terminals in said local office each having a corresponding number designation, identifying equipment at said local office including meeins for registering the di-,its of a line tern-iinal number designation, an intercept office including means for registering cared line number designations, means for intercepting calls to selected ones of said line terminals, means responsive to said intercepting means for connecting said identifying equipment with a called one of said selected line terminals to register the number designation of said cajled line terminal, means under the control of said intercepting 3,143,601 means and said registering- means -to transmit the- digits of said called line terminal number designation to said intercept office, and means operative upon the completed operation of said transmit means for connecting said intercept office with said called line terniinal. I 1. A telephone switehing system according to claim 10 wherein some of said plurality of line terminals are associated with two party lines, each party line having a distinct number designation, said intercepting means comlo prising means for identifying the called party line on an intercepted call to one of said plurality of line terminals assoc'ated wit-h two party lines and means for providing the party line idetitification to said identifying equipment. 12. In a telephone switching system, a local office, a i.5 plural-ity of lines in said local office each having a corresponding directory number, means for marking a calling one of said lines, means for intercepting and maxking a called one of sa@id lines, line identification equipment 'Lor detecting a ma@-ked one of said lines, means under the control of said deecting means to register the director number corresponding to a marked line, mea-iis operative to transmil directory numbers registered in said register means, an intercept office, means responsive to said intercepting and markin.- means for providing a transmission 25 co-ii-tiect@'on between said intercept office and said transmit means, and means for disconnecting said transmit m-,ans from said int,-rcept office and for connecting said intercept office to said calling one of said lines upon the complet,-d operation of said transmit means. 30 13. In a telepho-@ie switching system, a plurality of lines eacil having a correspondin.- directory number, means for marking a calling one ol' said lines, means for intercepting and riiarking a called one of said lines, line ident,'.fieation equipment including means for detecting a 35 marked one of said lines and means under the control of said detecting means to identify the directory number of a rnarked one of said lines, a first outgoing trunk circuit, a second outgoing trunk circuit, means under control of a calling line for connecting said lirie identification equip40 ment to said first outgoing trunk circuit, means under control of said intercepting means for connecting said line identification equ4pment to said second outgoing trunk circuit, and switching means controlled by said line identification equipment and said intercepting means for con45 necting said called line to said second outgoing trunk circuit, No references cited.

Pr @ United States Patent Office 3@143,601 P a t e n t e d A u g . 4 , 1 9 6 4 3,143,6 01 ALTT OMATIC NIJNM--'@R LNTI-QRCEPT IDENTIFICA TION SYSTEIM Amos E. Joel, Jr., South Orange, N.J., assignor to Ben 5 Telep hone Laborator@es, Incorporated, New York, N.Y., a corporation of New York Ffied Sept. 20, 1962, Ser. No. 224,984 13 Claims. (Cl. 179-1-7) This invention relates to automatic telephone switchin.@ 10 system s and more particularly to arrangements for iriprovin .- call intercept service in such systems. ,la automatic telephone switchin- systems it is desirable to minimize both the necessity and the time required for operat or assistance in the handling of caus. Occasionally, 15 a call cannot be completed to the number dialed by the caring party because that number has been discontinued or changed, or is otherwise unavailable for completion of the caR in the normal manner. Where the number dialed by the cauin.- party does not exist or has been discon- 20 tinued, arran.-ements are known for intercei)tin- and extendin g the call to a recorded announcement . machine which provides suitable instructions to the cauing party. Some caU situations, however, do not lend themselves to a uniform recorded announcemerit, but rather require 25 individ ual service. An example of such a situation is where the cared party has recently changed to a new director y number and the old directory number has not been reassigned. Existing telephone practice provides for the interception and routing of such caus to manual 30 interc ept operators who must request the number dialed by the calling party, refer to a changed number directory to determine the new number, and inform the cahing party thereof. The practice of requiring th,- operator to req-,iest the 35 numbe r dialed by the cahing party has several inherent disadv anta,-es, one of which is the cauing party confusion which can result from the appearance of the intercept operat or on the line requesting the number dialed. 7his often leads to the cauing party initiafly relatin@ his own 40 direct ory number to the operator rather than that of the cal'ied party and, accordingly, requires additional operator assistance time in the handling of the call. Further misun derstandin- develops where diaeng or switching equipi rient irre.@ularity results in reaching an intercepted 45 numbe r in error. Under present telephone practices, the interc ept operator has no way of knowing whether the interc epted number reached by the calling party correspond s to the number which the callin@ party attempted to reach. Therefore, it is desirable to provide circuitry 50 at the local office responsive to cahs to intercepted numbers to identify and forward the niimbers automatically to the intercept operator. Autom atic identification of intercepted numbers minimizes the time required for operator assistance, not only 55 in that it precludes the necessity for the operator requesti ng the numbcr dialed, but further in that the opportun ity for cauing party confusion is eliminated. Moreo ver, the identity of the intercepted number may be includ ed advantageously in th@- info.-mation related by 60 the intercept operator to the cauing party to eliminate any misunderstanding due to dialing or equipment irregula rities, thus improving the service to the customer Am additional advantage accruing from the automatic 65 identifi cation of intercepted numbers is that it provides a convenient method for maintaining a count of the calls to these numbers. This allows an efficient determination to be made ivhen the volume of calls to an intercepted numbe r has reduced to a level sufficient to permit reas- 70 signm ent of the number. Heretofore, reassig=ents have been made on the basis of general operating experience 2 without reference to the number of calls made to the individual number. Accordingly, it is a general object of this invention to improve telephone intercept service and to reduce the amount of operator assistance required in handling intercepted calls. More particularly, it is an object of this invention to provide a simple, compact and economical intercept circuit arrangement for automatically identifying the directory number of an intercepted call and for transmittinthe number to a central intercept office or operator's position. In certain automatic telephone switching systems in present use, such as those of the crossbar type, the number dialed by the caliing party is re.-istered in the terminating eq-aipment at the called party local ofhce. The called number itiformation remains registered in the terminating equ@.pment until the calling party connection is extended to the line terminals corresponding to the number dialed. If the called -iumber is arranged for intercept, therefore, the identity of the number may be obtained directly from the terminating equipment number regi-ters and forwarded to an intercept operator. A suitable intercept circuit arran,@ement for use in such switching systems is described in 0. Myers Patent 2,968,700, granted January 17, 1961. However, in other telephone switching systems, such as those of the step-by-step and pa-@el type, the dialed number informaton is not registered in the terminating office equipment, but rather is used and discarded in establishin.- the connection to the cahed party line terminals corresponding to the dialed number. If the number is arranged for intercept, the connection is extended through the line terminals to an announcement machine or to a manual intercept oi)erator. Inasmuch as the number dialed is not registered in the tern-linating office equipment, it cannot be forwarded therefrom to the intercept operator in the man--ier taught by the above-identified Myers patent. Of course, translatlon circuitry could be provided at each local office to translate the location of intercepted line terminals into the corresponding directory nlimbers and circuitry could be provided )'Or registering a--id forwarding these numbers to the ;ntercept onerator, but this would clearly be uneconomical in view of the small percentage of line terminals within a local of.'Ice which are arran.-ed for intercept at any one time. It is, therefore, another object of the Dresent invention to make maximum use of the existing circuitry at the local office to pro,,,ide for the identification and transmission of intercepted called directory numbers without requiring separate and additional translation and registration circuitry therefor. The above and other objects are attained in an illustrative embodiment of the present invention wherein improved intercept service is provided through the advantageous utilization of a portion of the identification equ,:pment provided at the local oflice for billing purposes. This identification equipment normally functions only on an outgoing billed call to identify the calling party's diectory number and to outpulse the number to a message accountin- office. Heretofore, this equipment has served no function with regard to calls incoming to parties at the local office. However, in accordance with the principles of the present invention, the identification equipment is arranged in conjunction with intercet)t circuitry to function both to identify callin.- party directory numbers on outgoin.- billed calls an'd, also, to identify called party directory numbers on intercepted incoming calls. The dialed directory number of the called party is employed in the normal manner by the local office switching equipment to establish the callin,@ party connection to the appropriele line terminals corresponding to the called

3,143,601 3 4 number. if the number is arranged for intercept service, the call is detected by intercept circuitry which seizes the identification equipment at the local office and initiati@,@s a connection throlgh to the intercept office. The called number sleeve terminal is marked by a si,-nal 5 which is directed through the identification eqlipment to identify and register tiae digits of the called number. 'vvheh the coriiplete called number has been re.-istered, it is transmitted to the intercept office. The identification equipment is then released, ringing is tripped in a manner 10 so as to prevent charging the calling party for the ca.1, and the callin.@ party connection is extended frorn the called ntimber line terminals to the intercept office. This - connection remaiiis under control of the calling party until he has received suitable instructions from the - intercept 15 office as to the current statlis of the called number. The intercepted number may be included advantageously in -the message to the calling party. Accord:n,-Iy, a feature of my invention relates to automatic equipment for intercepting calls to changed and 20 discontinued directory numbers, particularly in step-bystep and panel type switchin- system, for identifying the directory number of the intercepted call, and for forwarding the d;@rectory number to a central intercept office, Another feature of my invention relates to intercept 25 circuitry operative in conjunction with message accounting number identification equipment located at the tele phone local office to provide the directory number of an intercepted call to an intercept operator position. A further feature of my invention relates to circuitry 30 for employing local office number identification equip, ment both to identify calling line numbers for billing pur, poses an dto identify called line numbers for - intercept purposes. According to one aspect of the foregoing fea, ture means are provided for seizing the local office call, 35 ir@- line identification equipment incident to the comple, tion of an intercept call connection to identify the directory number of the called line. These and other objects and features of the present inventiorl may be better understood upon consideration of 40 the following detailed description and the accompanying drawing which, when FIG. 1 is arranged to the left of FIG. 2, shows an illustrative embodiment of an - automatic number intercept identification system in accordance with the principles of the present invention. 45 The illustrative embod-.Ment of the present invention is depicted in a telephone system of the step-by-step type represented schematically in the drawing. The subscriber stations 100, 102, and --104 and line circuits 101 are of -the usual type employed in such telephone systems; and 50 line finder switch LF, selector swi-'Ch LS and - connector sv,,itch LC are of the well-known two-motion step-by-step type. These switches ,,re each represented in the drawing by a s-tt of briiihes and one or more sets of terminals, all other switch elements and associated apparatus and con- 55 neciioiis thereto being omitted. A clear and - cornplete description of the structure and operation of such switches is found in "Automatic Telephony" by Sniith and Camp- - bell, 2jid edition, oages 53 through 67. Reference may also be had to Patent 2,210,068, granted to T. L. Di- 60 mond, August 6, 1940, for a description of a line finder switch of the step-by-step type. The invention is not, however, limited in its application to the particular system shown but is generahy applicable to all - automatic teleplione systems having cal]ing line directory nii-ber 65 identification apparatus. The rumber-identification,apparatus employed in the illustrative embodiment comprises number network 110, ide-iitifier, 120, outplilser 130, outpulser link 140, and outgoin,@ trunk 150, all of xhich are depicted in block dia- 70 gram form inasmuen as their details and i nterconnection may be f6tind in the copending application of H. D. -Cahill and C. H. Dagnall, Jr., Serial No. 658,384, ffled May 10, 1957, now Patent No. 3,071,650, issued January 1, 1963. The sleeve leads associated with subscriber stations 100, 75 19 102 and 104 are connected by individual conductors 105, 106 a,@id 107, respectively, to corresponding coordinate points in the resistive grid arrangement (not shown) in number network 110. The directory number significance of each @leeve lead is identified in terms of vertical and horizor@tal busses attached to the coordinate point in number network 110 to which the sleeve lead is connected. Cor@nceLed to number r@etwork 110 is identifier 120 which includes detector circuits that scan the horizontal and vertical busses in number network 1110 to find the ones thereof that are connected to the sleeve lead of the calling I;ne to be identified. Outpulser 130, vihich is connected to identifier 120, comprises circ-aitry for registering and checking the directory number digits representing the call-'@.-l-, line and circuitry for out-ouising the nuinber digits, along with an inforriation digit, on a multifrequency basis. Outpulser link IL40 provides the interconnection fac@lities betweeq outgoing trunk 150 and outpulser 130. Briefly, the operation of the identificalion apparatus in identifying the directory nu-mber of a calling line and forwarding the nui-p@ber to an accounting center for billing purposes is as follows: when a calling party, e.g., subscribe@ station 100, initiates a call for which the station is to be bill,-d by centralized automatic message accountin.- (CAMA) equipment, the automatic switching apparatus operates as usual under control of the calling station's dial to extend the tip, ring and sleeve leads of the cql'iing station through line finder switch LP and through one or more selector switches LS to an outgoing trunk -150. At the same time t)arty information is passed to trunk 11-70. The call proceeds in the normal i'aswon untfl the dialed number has been transmitted through otitgoing trunk 150 to a sender (not shown) at the CAMA office. At that point a request from the CAMA office for identification of the calling line directory number brihgs the identification apparatus into operation. Outgoing trunk 150 recognizes the identification request from the CAMA office and establishes connections through preferencing circuitry in outpulser link 140 to an idle outpulser 130. Trunk 150 passes the party information to outpulser 130. By means of connecting facilities within itself, outpulser 1130 seizes an identifier 120 and passes the party information thereto. Identifier 120 registers the party information and con-iiects the number network 110. Thereupon, outgoing trunk 150 marks the calling Ene sleeve lead by superimposing an alternating-current identification signal on the sleeve lead holding groiind toward line circuit 101. The identification signal finds its way back through the switchin@- train over the sleeve lead of the callin.- line and along conductor 105 to number network 110. The signal thus appears on the horizontal and vertical busses uniquely corresponding to the directory number of the calling line, where it is detected by identifier 120 and transferred to digit registers in outpulser 130 in two-out-of-five coded form. A single information digit is also registered in outpulser 130 to indicate certain conditions, e.g., whether identification was successful or whether the assistance of a CAMA operator is required. Assuming identification to be successful,- identifier 120 is released and outpulser 130 proceeds to oupulse the information digit followed by the calling line directory number digits to the CAMA office on a multifrequency pulsing basis. Outpulsing is preceded, as is customary, by a key pulse signal which prepares the multifrequency receiving equipment in the CAMA office for receiving the multifrequency pulses. Outpulser 130 is then released and outgoing trunk 150 completes the transmission path with talking battery and supervision toward the calling party and with trunk supervision toward the CAMA office. If identification of the calling line directory number is un@uccessful, only thecorresponding information digit is outpulsed and outpulser 130 releases itself. The present invention contemplates the advantageous utilization of such directory number identification apparatus, in conjunction with intercept circuitry, to@function

5 both to identify the calling line directory ntimber on outgoing CAMA-billed calls and to identify the direc-tory number of caued lines on interce-oted calls. The operation of the identification apparatus in identifying call;n,- line directoi-y numbers for bihin- purposes is unchanged from that described briefly above and in greater detail in the above-mentioned Cabill-Dagnall patent. The manner o" gaining access to the identification apparatus and the operation thereof in identifyin,@ and forwarding to a central intercept office the directory number of an intercepted call is described in detail below. However, initially it may be noted that the idenlifica@' ,@On apparati-is operates on a oneat-a-time basis,. and thus access to the iden@Lification apparatus for intercept identification purposes and access thereto for calliii.@ line identification purposes must be in a mutual lockout relationship. In the illustrative embodiriient described below, th-.s is hand'ied wi:-@h a miniin-tim of additional circuitry by havirig both identificatiop- s-' tuations app.-ar the same to the identificatioa apparatus, atiy use of the identiicatiori apparaLLs therefore busyin-. th-- equipment to all ot,ier requests durh-ig the use thereof, whe',her for intercept or for billing purposes. More part:@cil-larly, as described -in the aboveide-.i@,if-ed Cahill-Dagnall patent, outpulser ILnk 140 comprises a plurality of trunk preference relays (noL shown) connected in a prefere-.ice chain arrangemenl. Each outgoin@ trunk circuit l@-;'3 is co@irected to an ind-tvidual one Of the trunk prei'ereice relays. In a similar manner, in the illustrative embodiment of the present invertion, i--iidividual trunk preference relays are provided in the preferenc-- chain arrangem@-nt in outpulser link 140 for each 'lia.,:y intercept 'Lrw-ik 50. Thus, both outgoing tr-unk aux., circui'LS 150 atid a-axiliary interceot truqk circu-its 50 appear the saric to the identification equipme-.it, and no more than one triink circuit at a time can ga:.n access thereto. Before proceeding with a descriptioil of the intercept circuitry and the operation thereof in conjunction with the above-described ideriti.acation equipment to identi.Ly called line - iiuriibers o-ii inlei-cepted calls, it might b@- well to briefly consider the op-.rat:lon of the i'ilus@rative 'Lelephone sys@em on ai incomin.- call. Each subscriber sta0 @ft -ig tion is c nnected throu terniinals of a main distributii fra.me MDF to an indi-vdual set of terml-ials, such as terminals I'@4, in conne-ctor switch LC. The individual sets ol. terminals of coinector sw;tch LC eacii have permane.-itdire@-tory number significance, ard a particular directory number is thus assigncd to asubscr:@ber station via cross connee'L,'@ons at ma,@-il distributin@. frame MDF. On a ca,'tl to subscriber station 100, for exarrple, tb-e automatic te'iephone switcil@---g eci,,ii-oment respotids to the dialed direc,Ory nur-,lber correspoliding thereto to co-.i-icet the calling li.--e to the connector switch LC having access to set of terminals 11. Connector switch LC mak-es a busy test of the called line and, i@l the line is idle, tb-e calling line covineelion is extended throi,--,@ia set of terminals 11 a-@id trl-e cross co--mections at frawe MDF to sdbscriber station 100. A ringing circu@.t -@'S connected to tne tip and rL-i.@ leads of th-- cailc,-i line and a coiatact K of the line connector LC is c'.osed 10 ground th-- sleeve lead of the cailed line as an indication to subsequent calls that the line is busy. (Conventioiially, ground -is directly applied by contact K, @-owever, as will h--reinaft---r be pointed out in relation to the invention, it is desirable that this ground b-. prw.,ided to contact K over an inductor 7.) V,I,Ijaen the called s-,lbscr-iber sta-,ion 100 answers, ringing is tripped and the cotiversat@on path completed; however, the sleeve lead ground remains for the duration of the call uni:,l tne caliir.@ party discoiinects. Subscriber statioq .104 is similarly assigned a particular directory number via cross connections at.Lrame MDF to terminals 10 in co-mector s-,vitch LC. Now assume, for -ourroses o-@9 de.-crib,.n.- the present inventio-ii, that sub@-criber stal;on '.04 has receptly changqd to a new direclory nu@nber. Thus the cross connections 3,143,601 6 at frame MDF between subscriber station 104 and set of terminals 10 are disconnected, and subscriber station 104 is connected to a dlfferent set of terminals which correspond to the new directory number. Set of terminals 10 i-.i connector s,,vitch LC no longer corresponds to the directory number of subscriber station 104, but retains its identity with the old directory number of steion 104. For some indeterm;nate per:iod of time after the directory number cha-ilge, persons un-"nformed of the chan@-e Will 10 conLL-iue 'Lo attempt to reach subscriber station 104 by dialing the old directory nut-nber. During at least a part of th:ls period of time the old directory number, and thus set of terminals 10, will not be reassigned to a different subscriber station. It is therefore necessary, as dis15 cussed abo-ve, to ;ntercept calls to the old directory number corres-,3o-ilding to terminals 10 apd to inj'orm the calling party of the new directory number of subscriber station 104. For this purpose, auxiliary intercept trunk 50 is pro20 v.;ded to intercept calls to predetermined directory numbers and to extend the connection from the calling line throu.-h to a central intercept office or intercept operator's position. Auxiliary intercept trunk 50 further functions advantageously in conjunction with the number identifica25 tion apparatus provided at the local office for billing purt)oses to identify and to forward the identity of the calfed directory number to the intercent office or operator's posit-ion. As illustrated in the @rawing, intercept trunk 50 mav serve a plurality of directory numbers for 30 which it is desired to intercept calls directed thereto. Each such directory number is arran,@ed for intercept by disconnecting any subscriber station equipment from the connector switch terminals corresponding to the directory number. The conncctor switch terminals are then con35 nected to individual intercept re'@ays, such as relays ITR-1 and --LTR-n, in auxiliary intercept trunk 50. Connector switch terminals 10 are arranged for intercept, fo.- example, by connecting the tip and ring lead connections thereof v-.n, conductors 12 and 13 through individual 40 windir@gs of -intercept relay ITR-1 to tip bus 15 and ring bus 16, respectively, in intercept trunk circuit 50. When relay ITR-1 is normal, the sleeve lead connection of terminals 10 is connected via cond-actor 14 throu.-h a back contact ITR--I(I) to busy conductor 17. When 45 relay ITR-1 is operated, conductor 14 is connected throu.-h j'ront contact ITR-1(2) to sleeve bus 18. A plural;ty of intercept trunks such as trunk 50 are individually connected via their respective tip and ring busses to sets of terminals in banks of trunk finder switch 50 TF. Trunk fLTider switch TF may be similar to line finder switch LF, and is represented in the drawing by a set of brushes and a set of terminals all other switch elements and associated apparatus and c@nnections thereto being omitted. Trunk finder switch TF is provided to 55 concentrate the intercepted traffic over a smaller group of trunks, e.g., outgoinintercept trunk 80, to the central ;ntereept office or operator's position conimon thereto. The operation of tt-le present automatic number intercep, @dentiiication arrangement will be fully understood 60 from consideration of a typical call from a party attempting to reach subscriber station 104 by dialing the old directory nurri-ber correspondin- to terminals 10 in connector switch LC. Under control of the calling party's dial the switching equipment extends the calling party 65 connection to connector switch LC. A busy test is made of terminals 10, and assuming auxiliary intercept trunk 50 connected thereto to be idle, the tip, rin.- and sleeve leads to the callin,@ party are exter@ded through terminals 10 to tr-unk 50. Connector switch LC connects a rin@ ing circuit to the tip and ring leads and closes contact K io to ground the sleeve lead. Assuming the directory number dialed to correspond to a single-party line or to the ring party of a two-party line, therefore, the ringing source is applied to the ring lead and ringing ground is 7,5 applied to the tip lead as shown in the drawing. The

7 ringing signal on the ring lead is continued over conductor 13 through the lower winding of intercept relay ITR-1 to ring bus 16 and operates alternatin-,current relay RR, the path therefor be:ing corlpleted from ring bus 16 through a back contact TT(3) and the winding of relay RR to @yound. Intercept relay ITR-1 is not opera@ed by the alternating-current ringin- si,@nal through its lower winding. The ground applied throu,-h contact K (FIG. I 1) to the sleeve lead busies terminals 10 for any subsequ-,nt calls to the directory number correspondinthereto unt,.1 10 the present caring party disconnects. The operation of relay RR completes an obvious path from ground through a front contact RR(l) and the winding ol@ relay RRI to battery, thereby operatinrelay RR1. In operating, relay RRI locks up to the sleeve 1.5 lead ground through a circuit including front contact RR'.(4), back contact TT(6) ' conductor 17, back coiitact ITR-1(1), conductor 14 and the sleeve lead connection of terminals 10. Operation of relay RRI comd!etes a circuit from battery through front contact RRI(l), 20 back contact TT(l), tip bus 15, Llie upper w,'@nding of relay ITR-1, conductor 12 and the tip lead connection of terminals 10 to the ringing ground. This operates intercept relay ITR-1 which transfers the connection of conductor 14, and thus the sleeve lead of the cared num- 25 ber, from busy conductor 17 to sleeve bus 1,8 through a front contact ITR-1 (2). Operation of intercept relay ITR-1 operates relay !TR which grounds busy conductor 17 through front contact ITR(l). Contact ITR(L) operates to ground busy con- 30 ductor 17 upon the energization of any of the interceot relays in trunk 50, such as rela@,s ITR-1 and ITRN. Busy conductor 17 is connected th,-ough back contacts of the other intercept relays, such as intercept relay ITR-N, to the sleeve lead terminals in co-mector switch 35 LC of other directory numbers arranged for intercept. The ground on conductor 17, therefore, busies intercept trunk 50 to calls directed to these other directory nur@ibers darin.@ the use thereof for the call intercepted at terminals 10. Further, operation of intercept relay 40 RFR-IL transfers the locking circuit for relay RRI from the sleeve lead holding ground to the busy conductor ground through contact ITR(1). Seizure of the number identification apparattis for identification of the directory number of the intercepted call 45 is initiated by the operation of relay RRI. Battery is applied through front contact RRI(7), back contact SP(8) and start lead ST to outpulser link circuit 140. Lead ST is connected to the windin.- of a trunk preference relay (not shown) individual to trunk circuit 50 50 in outpulser link circuit 140. Assuming that no other intercept trunk circuit and that no other outgoing trunk circuit 150 is seekin-, an outpulser at this time, the trunk preference relay individual to trunk circuit 50 operates to effect the seizure of an idle outpulser 130. Leads SP, R, T and A-B are extended from intercept trunk circuit 5,5 50 throu.-h outpulser link circuit 140 to outpulser 130. At this time party line identification is passed to outpulser 130. Since it was assumed that the called directory number was a single-party line, or a ring party on a two-party line, relay RR and relay RR1 operated as 60 described above. Operation of relay RRI connects ground through front contact RRI(3) and back contact SP(3) over lead R to outpulser 139. The ground on lead R operates a relay (not shown) in outpulser 130 to register the party inforr.,iation. 65 Upon proper registration of the pa:.-ty information, outpulser 130 grounds lead SP to trunk circuit 50 to complete a circuit through back contact SP(-) and the winding of relay SP to battery. Relay SP operates in this cir70 cuit and locks through front contact SP(5) thereof and front contact RRI(5) to ground. In operating, relay SP disconnects its winding and battery from lead SP and connects ground thereto through a winding of relay SPI. Operation of relay SP also disconnects -ground from lead 75 R to outpulser 130 and battery from lead ST to _outpulser link circuit 140. The connection of ground to lead SP is recognized by outl)tilser 130 that relay SP has o _perated. Outpulser 130 then alters several internal connections and applies battery to lead SP to complete a circuit through front contact SP(6), the winding of relay SPI, and front contact RRZ(5) to ground. Relay SPI operates in this circuit. Outpulser 130 then makes a test to insure that the call has not beei. abandoned b-,fore con@iecting to identifi--r 120. For this purpose, a circuit is closed from battery in outpulser 130 through lead R, inductor 57, back c6ntact MF(5), front contact RRI(2), front contact SPI (I) and lead T back to ground in outpulser 130. If the call is abandoned by the calling party before this point relay RR1 will be released, opening the circuit just traced. Assuming that the circtiit is complete outpulser 130 connects to identifier 120 and, in doin.@ so, removes battery from lead SF, releasing relay SPI. The party Une identification is passed by outpulser 130 to identifier 120, which makes the proper connections to nurnber network 110. The n-,ir@iber identification apparatus is now ready to identify the called line directory number on the intercepted call. With rclay SPI released, a circuit is conipleted from b,,ittery through a w-Anding of relay TN, back contact SPI(2), front contact SP(l), back conlact MF(6) and lead R to ground in outpulser 130. Rel,,ty TN operates in this circuit and closes a eir--uit from battery through front contact RRI (7), front contact TN (2) and lead T to outi)uiser 130. Toile oscillator 75 (FIG. 1) is rendered effec'Live by identifier 120 through the connection of ground to lead 77, and the operation of relay TN connects tone supplied by oscillator 75 through front contact TN(l) to sleeve bus 13. The tone on sleeve bus 18 is directed throu.-h front contact ITR-1(2) to conductor 14, and thence along lead 105 to number network 110. Inductor 7 in connector switch LC insures that the tone signal on conductor 14 will be directed along lead 105 to number network I'@10. The tone signal thus appears on the horizontal and vertical busses in number iietwork 110 uniquely corresponding to the directory number associated with s6t of terminals 10. The tone is detected by identifier 120 to identify the called directory number and to transfer the number to digit registers in outpulser 130. AfLer checking to see that all of the directory number digits have been identified and registered, outpulser 130 releases identifier 120 and disconnects ground from lead R to intercept trunk circuit 50. Relay TN is thereby released, disconnecting the tone signal from sleeve bus 18 and disconnecting battery from lead T to outpulser 130. Outpulser 130 detects the removal of battery from lead T and prepares itself for transniitting the identified directory number of the intercepted call to the central intercept office. To prepare intercept trunk 50, outpulser 130 grounds lead AB to complete a circuit through front contact SP (7) and the winding of relay MF to battery. Relay W operates in this circuit to connect leads R and T to the set of terniinals 78 of trunk finder switch TF. Operation of relay MF also completes an obvious circuit operating relay MFI, which locks through front contact MFI (3) thereof and front contact RRI (6) to ground. Outpulser 130 now closes a direct-current path across leads R and T, completing a circuit through front contacts MF(2) and MF(4) to operate trunk finder switch TF in the normal manner. Brushes in trunk finder switch TF connected to a trunk to the intercept office, such as outgoing intercept trunk 80, find the terminals 78 associated with intercept trunk 50 and complete the connection between trunk 50 and outgoin-, trunk 80. The outpulsing circuit is then complete from outpulser 130 through leads R and T, front contacts MF(2) and MF(4), terminals 78 of trunk finder switch TF and outgoing intercept trunk circuit 80 to a multifrequency receiving circuit 92 at the intercept office equipment. Transniission of the identified directory number of the intercepted cafl to the