Reviews Telephony

Telephone Tone Frequencies

Telephone Tone Frequencies

The Low Tone is a generic tone used with numerous interruption patterns for the precise tones listed under:

Line Busy Tone
Reorder
Reverting Tone
No Circuit Tone
No Such Quantity
Vacant Code
Group Busy Tone
Deposit Coin Tone
Vacant Place Tone
Dial Off-Regular Tone
Hassle Tone
Dial Jack Tone
Dial Check Sign
Class of Service

Low Tone is 480 Hz and 620 Hz at -24 dBm0/frequency. On some methods manufactured earlier than 1974, Low Tone was 600 Hz modulated at 120, 133, 140, or 160 Hz at 61 – 71 dBrnC.

Excessive Tone

The Excessive Tone is a generic tone used with numerous interruption patterns for the precise tones listed under and described beneath their very own titles:

Partial Dial Tone
Everlasting Sign
Coin Return (Check) Tone
Coin Return Tone
Quantity Checking Tone
Intercepting Loopback Tone
Warning Tone
Order Tone
Station Ringer Check
Class of Service

Excessive Tone is 480 Hz at -17 dBm0. On some methods manufactured earlier than 1974, Excessive Tone was 400 Hz or 500 Hz at 61 – 71 dBrnC.

Dial Tone

Dial Tone is shipped to a buyer or operator to point that the receiving finish is able to obtain dial pulses or DTMF alerts. It’s utilized in all varieties of dial workplaces when the client’s or operator’s dials produce dial pulses. Usually, dial tone signifies that all the needed quantity could also be dialed. Nevertheless, there are some instances the place the calling celebration should await a second dial tone or the place an operator, after dialing an preliminary group of digits, should anticipate a second dial tone earlier than the remainder of the quantity could be dialed. Some dialing switchboards are organized to allow listening for dial tone between sure digits.

Dial Tone is 350 Hz and 440 Hz held regular at -13 dBm0/frequency.

Audible Ring Tone

Audible Ring Tone is a ringing indication that the calling celebration intercepts to imply that the referred to as line has been reached and that the ringing has began. Additionally it is used on calls to operators (particular service, lengthy distance, intercepting, and so forth.) in the course of the “awaiting-operator-answer” interval.

Audible Ring Tone is 440 Hz and 480 Hz for two seconds on and four seconds off at -13 dBm0/frequency.

Line Busy Tone

The Line Busy Tone signifies that the referred to as buyer’s line has been reached however that it’s busy, being rung, or on everlasting sign. When an operator applies a line busy sign, it’s typically referred to as a busy-back tone.

Line Busy Tone is a Low Tone that’s on and off each .5 seconds.

Reorder

The Reorder Tone signifies that the native or toll switching or transmission paths to the workplace or gear serving the referred to as buyer is busy. This sign might point out a situation akin to a timed-out sender or unassigned code dialed. Both a buyer or an operator interprets it as a reorder sign.

Reorder on an area name is Low Tone for .Three seconds on and .2 seconds off. Reorder on a toll name is Low Tone for .2 seconds on and .Three seconds off. In No. 5 crossbar, No. 1/1A ESS, No. 2/2B ESS switching gear, and No. 1 step-by-step workplaces utilizing the Exact Tone Plan, the temporal sample is zero.25 second of low tone and zero.25 second off.

Alerting Tone

The Alerting Tone signifies that an operator has related to the road (emergency interrupt on a busy line throughout a verification name).

Alerting Tone is 440 Hz on for two seconds after which on once more for .5 seconds each ten seconds.

Recorder Warning Tone

When recording gear is used, the Recorder Warning Tone is related to the road to tell the distant social gathering that the dialog is being recorded. The tone supply is situated inside the recording gear and the get together making use of the recording gear to the road can’t management it. The regulation requires this tone and it’s recorded together with the speech.

Recorder Warning Tone is a .5 second burst at 1400 Hz each 15 seconds.

Recorder Related Tone

The Recorder Related Tone informs the client that his/her name is related to a recording machine and that he/she ought to depart a message, dictate, and so on. It’s to be distinguished from the recorder warning tone, which warns the client that his/her 2-way dialog is being recorded.

Recorder Warning Tone is a .5 second burst at 440 Hz each 5 seconds.

Reverting Tone

The identical sort of sign as line busy tone is used for the Reverting Tone in all techniques. In No. 5 crossbar methods, a second dial tone is usually used when a calling get together identification digit is required. The Reverting Tone informs the calling subscriber that the referred to as social gathering is on the identical line and that he/she ought to hold up whereas the road is being rung.

Reverting Tone is Low Tone on and off each .5 seconds at -24 dBm0/frequency.

Deposit Coin Tone

The Deposit Coin Tone, despatched from a Group Dial Workplace to a post-pay coin phone, informs the calling social gathering that the referred to as celebration has answered and that the coin ought to be deposited.

Deposit Coin Tone is a gentle Low Tone.

Receiver Off-Hook Tone

The Receiver Off-Hook Tone causes off-hook clients to exchange the receiver on-hook on a everlasting sign name and to sign a non-PBX off-hook line when a switchboard operator operates the ringing key.

Receiver Off-Hook Tone is 1400 Hz, 2060 Hz, 2450 Hz, and 2600 Hz at zero dBm0/frequency on and off each .1 second. On some older area division switching techniques, Receiver Off-Hook was 1400 Hz, 2060 Hz, 2450 Hz, and 2600 Hz at +5 VU on and off each .1 second. On a No. 5 ESS, this continues for 30 seconds and on a No. 2/2B ESS, this continues for 40 seconds. On another AT&T switches, there are two iterations of 50 seconds every.

Howler

In older workplaces, this Howler tone informs a buyer that their receiver is off-hook. Nevertheless, the Receiver Off-Hook Tone has outmoded it.

The Howler Tone was a 480 Hz tone incremented in quantity each second for ten seconds till it reaches +40 VU.

Partial Dial Tone

Partial Dial Tone notifies the calling social gathering that he/she has not commenced dialing inside a pre-allotted time, measured after dial tone receipt (everlasting sign situation), or that he/she has not dialed sufficient digits (partial dial situation). This can be a sign to hold up and dial once more.

Partial Dial Tone is a gentle Excessive Tone.

No Such Quantity a.okay.a. “Cry Child”

The No Such Quantity Tone tells the calling celebration to hold up, examine the referred to as quantity, and dial once more. In trendy techniques, calls to unassigned or discontinued numbers may even be routed to a machine announcement system, corresponding to 6A or 7A, which verbally provides the required message. In some older workplaces, customers might be routed to an intercepting operator. In some workplaces, the reorder tone is returned on this situation.

No Such Quantity is 200 to 400 Hz modulated at 1 Hz, interrupted each 6 seconds for .5 seconds.

Vacant Code

The Vacant Code Tone is utilized in crossbar methods to point that the dialed workplace code is unassigned. In step-by-step areas, this sign known as vacant degree tone. For operator-originated calls, two flashes precede the verbal announcement. In trendy methods, recorded verbal bulletins are used for this service.

Vacant Code is Low Tone for .5 seconds on, .5 seconds off, .5 seconds on and 1.5 seconds off.

Busy Verification Tone (Centrex)

The Busy Verification Tone is a Centrex function that permits the attendant to name and be related to a busy Centrex station inside the attendant’s buyer group. The busy verification tone is utilized to each events of the connection to tell them of the attendant’s intrusion. No tone is utilized if the station referred to as for busy verification is idle.

Busy Verification Tone (Centrex) is 440 Hz at -13 dBm0 for 1.5 seconds after which once more for .Three seconds each 7.5 to 10 seconds. On a No. 1/1A ESS, Busy Verification Tone (Centrex) is 440 Hz at -13 dBm0 for 1.5 seconds after which once more for .Three seconds each 6 seconds.

There’s additionally a TSPS Busy Verification tone, which is 440 Hz at -13 dBm0 for two seconds after which on once more for .5 seconds each 10 seconds.

Name Ready Tone

Name Ready is a particular service that permits a busy line to reply an incoming name by flashing the switch-hook. Audible ring (as an alternative of line busy) is utilized to the calling line and the Name Ready tone is utilized to the referred to as line. (In order that solely the referred to as get together hears the tone, the connection is momentarily damaged and the opposite celebration to that connection experiences a second of silence). Flashing the switch-hook locations the prevailing connection on maintain and connects the client to the ready name.

The Name Ready Tone is 2 bursts of 440 Hz at -13 dBm0/frequency for .Three seconds plus or minus ten % each ten seconds.

Affirmation Tone

The Affirmation Tone acknowledges receipt by automated gear of data needed for particular providers. It’s at present used for:

  1. Velocity Calling – dialed quantity has been recorded
  2. Name Forwarding – dialed quantity has been recorded and repair is activated
  3. Name Forwarding – service is deactivated

Affirmation Tone is 350 Hz and 440 Hz at -13 dBm0/frequency on for .1 second, off for .1 second, then on for .Three seconds.

Indication of Camp-On

The attendant camp-on service permits an digital switching system Centrex attendant to carry incoming calls to busy strains. Every time the attendant releases his/her speaking connection from the loop concerned within the camped-on name, the referred to as buyer hears the indication of camp-on tone if the client has subscribed to the indication of camp-on choice. The client might get this tone a number of occasions because the attendant reconnects and releases from the loop in response to timed reminders from the console.

Indication of Camp On is 440 Hz at -13 dBm0 for one second each time the attendant releases from the loop.

Particular Dial Tone

Particular Dial Tone is used with Three-Approach Calling, Centrex station dial switch, and Centrex convention (station or attendant) providers. The consumer on an present connection flashes the switch-hook, receives particular dial tone, and dials the third social gathering’s quantity to be added to the connection.

Particular Dial Tone is 350 Hz and 440 Hz at -13 dBm0/frequency for .1 second on, .1 second off, .1 second on, .1 second off, .1 second on, .1 second off, after which on regular.

Precedence Audible Ring (AUTOVON)

The Precedence Audible Ring Tone replaces regular audible ring for precedence calls inside the AUTOVON community.

Precedence Audible Ring is 440 Hz and 480 Hz at -16 dBm0/frequency on for 1.65 seconds and off for .35 seconds.

Preemption Tone (AUTOVON)

The Preemption Tone is offered to each events of a connection that a precedence name from the AUTOVON community preempts.

Preemption Tone is 440 Hz and 620 Hz at -18 dBm0/frequency regular for anyplace from three to fifteen seconds.

Knowledge Set Reply Again Tone

The Knowledge Set Reply Again Tone is heard when manually initiating a knowledge name. It usually happens shortly after the beginning of audible ringing and signifies that the distant knowledge set has answered. The info set on the calling finish ought to then be put into the info mode.

Knowledge Set Reply Again Tone is 2025 Hz regular at -13 dBm.

Calling Card Service Immediate Tone

The Calling Card Service Immediate Tone informs the client that his/her bank card info have to be keyed in. The primary 60 milliseconds of this composite tone is 941 Hz and 1477 Hz, which is the DTMF ‘#’. This tone will launch and DTMF will dial pulse converter within the connection.

Calling Card Service Immediate Tone is 941 Hz and 1477 Hz at -10 dBm0/frequency at -Three Transmission Degree Level for 60 milliseconds then 440 Hz and 350 Hz at -7 dBm0 for .940 seconds exponentially decayed from -10 dBm per frequency at -Three Transmission Degree Level at time fixed of .2 seconds.

Class of Service

Class of Service alerts are used at a toll board working as an “A” board to determine the calling buyer’s class or service. The indication could also be excessive, low, or no tone.

Class of Service is a single burst of both Excessive Tone or Low Tone for .05 to 1 seconds.

Dial-Regular Transmission Sign

The Dial-Regular Transmission Sign is a second dial tone returned to an operator between digits indicating that he/she might dial the rest of the quantity. For instance, when an operator reaches a link-type Group Dial Workplace by way of a step-by-step workplace after dialing a routing code, he/she should pause till an idle hyperlink on the Group Dial Workplace returns dial tone. This technique of operation isn’t really helpful or thought-about normal.

Dial-Regular Transmission Sign is a gentle Low Tone.

Dial Jack Tone

Dial Jack Tone is used as a start-dial sign to inform a DSA operator that the connection reached via a dial jack is able to obtain dialing.

Dial Jack Tone is a gentle Low Tone.

Order Tone

Excessive tones despatched over interposition, native interoffice, or toll trunks point out:

  1. to the originating operator that the order ought to be handed
  2. to the receiving operator that an order is about to be handed

For Name Announcement and Automated Show Name Indicator, the tone serves perform two solely.

  1. Single-order tone – This can be a comparatively lengthy (zero.5 second) sign that signifies that the originating operator ought to cross the workplace identify and quantity.
  2. Double-order tone – This sign is 2 brief spurts in fast succession and signifies that the operator ought to cross solely the specified quantity.
  3. Triple-order tone – This sign is three brief spurts in fast succession and signifies that the operator ought to move the workplace identify solely and wait for an additional order tone.
  4. Quadruple-order tone – This sign is 4 brief spurts in fast succession and signifies that the operator ought to move the town identify solely and wait for an additional problem. It’s utilized in guide toll tandem (additionally referred to as zip tones or trunk task tones).

Single-order tone is one .5 spurt of Excessive Tone.
Double-order tone is 2 brief spurts of Excessive Tone.
Triple-order tone is three brief spurts of Excessive Tone.
Quadruple-order tone is 4 brief spurts of Excessive Tone.

Intercepting Loopback Tone

An Intercepting Loopback Tone despatched from an intercept operator to the ‘A’ board operator in guide workplaces signifies that an intercept operator has accomplished the decision and that the ‘A’ ought to disconnect from the circuit. The completion of intercepted calls on this method is not really helpful.

Intercepting Loopback Tone is a gentle Excessive Tone.

Quantity Checking Tone

The Quantity Checking Tone is usually used at DSA switchboards in No. 1 crossbar and a few step-by-step areas to confirm the calling line’s verbal identification.

Quantity Checking Tone is a gentle Excessive Tone. On some older methods, Quantity Checking Tone was a gentle 135 Hz tone.

Coin Denomination Tones

Coin Denomination tones allow the operator to find out the quantity deposited in coin telephones.

Coin Denomination Tones for the previous Three slot payphones have been:

Nickel – One faucet of 1050 Hz and 1100 Hz (bell)

Dime – Two faucets of 1050 Hz and 1100 Hz (bell)

Quarter – One faucet at 800 Hz (gong)

Coin Gather Tone

A Coin Acquire Tone over a coin recording-completing trunk informs the originating toll operator that the native operator or coin management circuit has collected the cost.

Coin Acquire Tone is a gentle Low Tone.

Coin Return Tone

A Coin Return Tone over a coin recording-completing trunk informs the originating toll operator that the native operator or coin management circuit has returned the change when the connection is just not accomplished (additionally referred to as coin refund tone).

Coin Return Tone is a single .5 to 1 second burst of Excessive Tone.

Coin Return (Check) Tone

Coin Return (Check) Tone tells an operator in a dial central workplace that a tester has accomplished a name to his/her place over a coin trunk.

Coin Return (Check) Tone is a single .5 to 1 second burst of Excessive Tone.

Group Busy Tone

Low tone on trunk jack sleeves at twine switchboards point out the Group Busy Tone. Absence of the tone tells the operator that there’s no less than one idle trunk in a gaggle.

Group Busy Tone is a gentle Low Tone.

Vacant Place Tone

The Vacant Place Tone is utilized to all simple trunks terminating in a vacated place in guide workplaces.

The Vacant Place Tone is a gentle Low Tone.

Dial Off-Regular Tone

Dial Off-Regular Tone is returned to an operator after he/she has accomplished a name right into a step-by-step workplace and after the calling social gathering has answered to remind him/her to revive the dial key.

Dial Off-Regular Tone is a gentle Low Tone.

Everlasting Sign

A buyer line that isn’t in use, which reveals a gentle off-hook situation is routed to a everlasting sign trunk. Excessive tone, superimposed on battery, is provided via a resistance lamp to the trunk’s ring. Everlasting Sign informs an operator or different worker making a verification check that the road is briefly out of service. An intermittent floor can also be utilized to the ring of the phone methods left within the maintain situation. Typical causes for the road situation are:

  1. No dialing inside the allowed ready interval.
  2. A handset is off-hook.
  3. Low insulation resistance or different line hassle.

In some workplaces, if three or extra digits are dialed however not an entire phone quantity or code, the decision is launched and dial tone is returned.

Everlasting Sign is a gentle Excessive Tone.

Warning Tone

A Warning Tone warns an operator that the circuit he/she is related to just isn’t in regular working situation. Examples:

  1. An operator at an Automated Show Name Indicator place plugs within the flawed jack.
  2. An operator at a sender monitor place plugs right into a sender supervisory jack whereas the sender is beneath check.

A Warning Tone is a gentle Excessive Tone.

Hassle Tone

A Hassle Tone that an operator or check individual at a B place in a guide workplace applies to the jack sleeve of a line or trunk in a calling a number of tells different operators the road or trunk is in hassle (additionally referred to as plugging up code tone).

A Hassle Tone is a gentle Low Tone.

Service Observing Tone

The Service Observing Tone signifies that the trunk to which it’s utilized is being service-observed.

The Service Observing Tone is a gentle 135 Hz.

Proceed to Ship Tone (Worldwide Direct Distance Dialing)

The Proceed to Ship Tone informs the operator that an abroad sender has been seized and the handle info (KP-CC-CC-ST) ought to be transmitted.

The Proceed to Ship Tone is a gentle 480 Hz at -22 dBm0.

Centralized Intercept Bureau Order Tone

Centralized Intercept Bureau Order Tone tells the centralized intercept bureau operator that a name has reached the place.

The Centralized Intercept Bureau Order Tone is a .5 second burst of 1850 Hz at -17 dBm0.

ONI Order Tone

ONI Order Tone tells the ONI operator that a name has reached the place.

The ONI Order Tone is 700 Hz and 1100 Hz at -25 dBm for .095 to .25 seconds.

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