==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