| ==Phrack Inc.== | |
| Volume Two, Issue 12, Phile #8 of 11 | |
| BUSY LINE VERIFICATION PART II | |
| WRITTEN BY PHANTOM PHREAKER | |
| This file is meant to be an addition to the first file that was included | |
| in Phrack Inc. Issue XI. It is assumed that the reader has read and understood | |
| the previous file. Most of this information will be taken from Bell System | |
| Publications so you don't have to worry about it being incorrect. | |
| First off, I'd like to correct a minor error included in the first file. I | |
| use the format 'KP+0XX+PRE+SUFF+ST' to show the MF routing that is used. This | |
| is not correct AT&T syntax though, the correct format is KP+0XX+NXX+XXXX+ST. | |
| This is minor detail, but some people are very picky. | |
| The Verification Network | |
| ------------------------ | |
| In a TSPS office, a verification circuit is associated with a 4-wire | |
| OutGoing Trunk (OGT) and a 3-way/4-wire bridging repeater arrangement. This is | |
| the circuit that does the speech scrambling. The speech and other tones (like | |
| busy and re-order) are frequency shifted, but are still recognizable by a TSPS | |
| operator. | |
| TSPS verification trunks are connected via dedicated lines to incoming | |
| verification trunks in a toll office. The toll office provides either a link | |
| to an outgoing trunk and dedicated facilities to another toll office, or an | |
| outgoing toll connecting trunk and dedicated facilities to an incoming | |
| verification trunk in a local office. Each toll office has ways to check the | |
| security of verification trunks. In electronic toll offices (ESS offices), two | |
| independent office data translations provide security of the trunk. Electro- | |
| mechanical toll offices (Such as a CrossBar Tandem (XBT)) use an electrical | |
| cross-office check signal or a segregated switching train to control trunk | |
| connections. Verification trunks relay supervisory signals (such as answering | |
| supervision) to TSPS from the line being verified. Also, if verification | |
| trunks are busy, the TSPS operator will receive a re-order. | |
| The functions of the VFY key | |
| ---------------------------- | |
| When the operator presses the VFY key, several checks are made upon the | |
| number that has been entered. These are: | |
| A Check to see if the line is within the verification network accessible | |
| by that particular TSPS. If the line is not, the VFY key will flash. | |
| A check to see if the owner of the line wishes BLV to be possible or not. | |
| If the line is something like a police emergency line, then the VFY key will | |
| flash, similar to the first check. | |
| Important TSPS keys | |
| ------------------- | |
| When the VFY lamp lights steady (doesn't flash), indicating the process is | |
| acceptable, the operator puts the calling customer on hold and accesses an | |
| idle loop on the operator position. The ACS (Access) lamp lights steady if a | |
| verification trunk is available at that time. Then, the operator presses the | |
| ST key which sends out the complete number to be verified, in MF. The | |
| verification circuit activates, and the operator listens for scrambled speech | |
| and also watches the CLD (Called) lamp on her console. The CLD lamp is lighted | |
| when the operator loop was accessed, and will remain lit if the line being | |
| verified is on-hook. The operator has two ways of seeing if the line is in | |
| use, by listening, and by watching the CLD lamp. If the CLD lamp light goes | |
| out, then the line is off-hook. | |
| If a successful BLV/EMER INT is performed, the operator presses the REC | |
| MSG MSG (Record Message) key, which completes the verification. If the EMER | |
| INT lamp is lit, the charges for the interrupt and the verification are | |
| automatically billed. If the VFY key is pressed twice, it indicates the | |
| verification should not be billed. This could be due to a customer error or a | |
| customer disconnect. | |
| Charging capabilities | |
| --------------------- | |
| A customer can pay for a BLV/EMER INT in several ways. They can have the | |
| charges put on their phone bill, if they are calling from their home, they can | |
| bill the charges to an AT&T Calling Card, or pay directly from a coinphone. | |
| Details of the BLV/EMER INT function are recorded on AMA tape, which is later | |
| processed at the RAO (Revenue Accounting Office). | |
| The classes of charge are as follows: STATION PAID, which means exactly | |
| what it says, STATION SPECIAL CALLING, in cases where billing is handled by a | |
| Calling Card or third number billing, and NO AMA, in unusual billing cases. | |
| Also, for BLV/EMER INT calls that originate from a hotel, TSPS can send | |
| charges to HOBIS (Hotel Billing Information System), HOBIC (Hotel Billing | |
| Information Center), or a TTY at the hotel. | |
| AMA records for BLV/EMER INT are recorded in basically the same format | |
| that normal calls are recorded. The only difference is that a numeric data | |
| group is added. The leftmost digit in the data group is a 1 if only a BLV was | |
| done, but it is a 2 if both a BLV and an EMER INT were done. In case of an | |
| aborted BLV, the billing record is marked 'No charge'. | |
| Inward Operator differences | |
| --------------------------- | |
| When an Inward operator does BLV/EMER INT, the class of charge is always | |
| NO AMA, because billing is handled at the local TSPS site. Inwards also do not | |
| use the REC MSG key when a TSPS would, they use the VFY key in it's place. | |
| The Speech scrambling technique | |
| ------------------------------- | |
| The speech scrambling technique that exists to keep the customers privacy | |
| intact is located in the TSPS console, and not in the verification trunks. The | |
| scrambling technique can only be deactivated by an operator pressing the EMER | |
| INT key, or a craftsperson using the console in a special mode. When the | |
| scrambler is deactivated by an operator doing an EMER INT, the customer hears | |
| an alerting tone (as mentioned in the first BLV file) made up of a 440Hz tone. | |
| This tone is initially played for two seconds, and then once every ten seconds | |
| afterwards until the operator presses her Position Release (POS RLS) key. | |
| Operator trouble reporting | |
| -------------------------- | |
| When operators have trouble in handling a call, they can enter trouble | |
| reports that are technically called 'Operator keyed trouble reports'. These | |
| cause messages to be printed on the maintenance TTY and on the trouble report | |
| TTY channel. There are different trouble codes for different things, such as | |
| trouble with the speech scrambler, trouble in the verification network, or | |
| trouble in collecting charges from a customer. | |
| In my area there are 20 such TSPS trouble codes. These are done in MF. | |
| They are entered with the KP TRBL (Key Pulse Trouble) key followed by a two | |
| digit trouble code followed by an ST. A trouble code for beeper trouble could | |
| be entered as KP TRBL+62+ST, and speech scrambler trouble could be KP | |
| TRBL+89+ST. Some of the other reasons for trouble codes are: Crosstalk, No | |
| ring, Noisy, can't hear, improper supervision toward the called and calling | |
| parties, cutoff, positions crossed, coin collecting trouble, third re-order, | |
| distant operator no answer, echo, data transmission, no answer supervision, ST | |
| key lit for more than 4 seconds, and others for person-to-person and | |
| station-to-station completed collect calls. | |
| Maintenance and traffic measurements | |
| ------------------------------------ | |
| These reports can be output from a maintenance or engineering and service | |
| data TTY, daily or hourly. Each daily report contains data for the previous | |
| day. Some traffic counts are as follows: | |
| Total Verification attempts, VFY key depressions, VFY key depressions when | |
| the requested number is out of TSPS range, VFY key depressions in which the | |
| requested number wasn't verifiable, BLV trunk seizures which pass an | |
| operational test, and EMER INT attempts. Other traffic counts include the | |
| measurements for usage of BLV trunks, the amount of time BLV trunks were | |
| unavailable, and the number of times BLV trunks were seized. | |
| I hope this file has helped people further understand how the BLV system | |
| works. If you haven't read part I, get a copy of Phrack Inc. Issue XI and read | |
| file #10. | |
| As said earlier, most of this information comes directly from Bell System | |
| Publications and so it should be viewed as correct. However, if you do find | |
| any errors then please try to let me know about them so they can be corrected. | |
| Suggested reading | |
| ----------------- | |
| TSPS Part I: The console-Written by The Marauder, LOD/H Technical Journal | |
| Issue No. 1, file #4 | |
| Busy Line Verification-Phrack Issue XI, file #10 | |
| Busy Verification Conference Circuit-Written by 414 Wizard | |
| Verification-TAP issue 88, Written by Fred Steinbeck | |
| Acknowledgements | |
| ---------------- | |
| Bell System Technical Journal, Vol. 59, No 8. | |
| Bell Labs RECORD periodical | |
| And the following people for contributing information in some form: | |
| Mark Tabas, Doom Prophet, The Marauder | |