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- ==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
- ===============================================================================
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