home *** CD-ROM | disk | FTP | other *** search
- ---(OOooOO)--------BT tones and announcments----------------------------(OOo-
- ---(OOooOO)--------by force---------------------------------------------(OOo-
- ---(OOooOO)--------force007@hotmail.com---------------------------------(OOo-
-
-
- 1. SCOPE
- »»»»»»»»»»
- This document describes the supervisory tones generated by the BT
- network and gives general information about BT network announcements.
- Tones and announcements encountered on the BT network can come from
- other networks, and customer premises equipment and these are not
- covered in this document.
-
- 2. NETWORK SUPERVISORY TONES
- »»»»»»»»»»»»»»»»»»»»»»»»»»»»»»
- The supervisory tones that will be returned from the BT network are listed in
- Table 1.
-
- Table 1. Network Supervisory Tones
-
- +===============================================================================================+
- | Network Generated | Significance | Range of levels | Tone Composition| Cadence |
- | Tone | | received at BT | ( 5% except | ( 10% except |
- | | | network interface | where stated) | where stated) |
- |===================|===================|====================|=================|================|
- |Proceed Indication |Proceed to dial |0 dBm to - 27 dBm. |350 Hz |Both tones |
- |(Dial Tone) |indication |Each tone separately|plus |continuous |
- | | |3 dB lower |440 Hz | |
- |-------------------|-------------------|--------------------|-----------------|----------------|
- |Special Proceed |Proceed to dial |0 dBm to -27dBm. |350 Hz |350 Hz tone - |
- |Indication |indication when |Each tone separately|plus |0.75 s ON. |
- | |certain |3 dB lower |440 Hz |0.75 s OFF |
- | |supplementary | | |plus |
- | |services have been | | |440 Hz tone - |
- | |invoked | | |continuous |
- | | | | |or both tones |
- | | | | |pulsed at the |
- | | | | |above rate. |
- |-------------------|-------------------|--------------------|-----------------|----------------|
- |Number Busy Tone |Called Customer's |0 dBm to -37 dBm. |400 Hz |0.375 s ON. |
- |(Engaged Tone) |line in use | | |0.375 s OFF. |
- |-------------------|-------------------|--------------------|-----------------|----------------|
- |Congestion Tone |Routeing equipment |-6 dBm to -43 dBm. |400 Hz |0.4 s ON. |
- |(Path Engaged Tone)|is temporally |0 dBm to -37 dBm. | |0.35 s OFF. |
- | |unavailable | | |0.225 s ON. |
- | | | | |0.525 s OFF. |
- | | | | |Note: Shorter |
- | | | | |tone is 6 dBm |
- | | | | |higher than the |
- | | | | |longer tone. |
- |-------------------|-------------------|--------------------|-----------------|----------------|
- |Special Congestion |Precedes some |0 dBm to -37 dBm. |400 Hz |400 Hz tone - |
- |Tone |congestion | |1004 Hz |0.2 s |
- | |announcements | | |1004 Hz tone - |
- | | | | |0.3 s |
- |-------------------|-------------------|--------------------|-----------------|----------------|
- |Connection Not |Call cannot be |0 dBm to -37 dBm. |400 Hz |Continuous |
- |Admitted Indication|routed to requested| | | |
- |(Number |number | | | |
- |Unobtainable Tone) | | | | |
- |-------------------|-------------------|--------------------|-----------------|----------------|
- |Awaiting Answer |Implies that called|0 dBm to 37 dBm. |400 Hz + 450 Hz |0.4 s ON. |
- |Indication |Customers line is | | |0.2 s OFF. |
- |(Ringing Tone) |being rung | | |0.4 s ON. |
- | | | | |2.0 s OFF. |
- | | | | |or 0.35 s ON. |
- | | | | |0.22 s OFF. |
- | | | | |Then start at |
- | | | | |any point in |
- | | | | |0.4 s ON. |
- | | | | |0.2 s OFF. |
- | | | | |0.4 s ON. |
- | | | | |2.0 s OFF. |
- | | | | |Note: Cadence |
- | | | | |does not |
- | | | | |necessarily |
- | | | | |coincide with |
- | | | | |call arrival |
- | | | | |indication |
- | | | | |cadence |
- |-------------------|-------------------|--------------------|-----------------|----------------|
- |Special Information|Precedes certain |0 dBm to -37 dBm. |950 Hz ▒ 50 Hz |Each frequency |
- |Tone |announcements | |1400 Hz ▒ 50 Hz |is sent for 330 |
- | | | |1800 Hz ▒ 50 Hz |ms ▒ 70 ms in |
- | | | | |the order given |
- | | | | |and with silent |
- | | | | |periods of up to|
- | | | | |30 ms between |
- | | | | |adjacent signals|
- |-------------------|-------------------|--------------------|-----------------|----------------|
- |Call Waiting |Indicates a second |0 dBm to -37 dBm |400 Hz |0.1 ON |
- |Indication |Incoming call | | |2 - 5 s OFF. |
- |-------------------|-------------------|--------------------|-----------------|----------------|
- |Special Call |Indicates a special|0 dBm to -37 dBm. |400 Hz |0.25 s ON. |
- |Waiting Indication |second incoming | | |0.25 s OFF. |
- | |call | | |0.25 s ON. |
- | | | | |0.25 s OFF. |
- | | | | |0.25 s ON. |
- | | | | |5.0 s OFF. |
- |-------------------|-------------------|--------------------|-----------------|----------------|
- |Pay Tone |Indicates credit |0 dBm to -37 dBm. |400 Hz |0.125 s ON. |
- |(Payphones) |expiry to payphone | | |0.125 s OFF. |
- | |(and called) | | |Continues for |
- | |customer | | |11 s to 13 s or |
- | | | | |until money is |
- | | | | |inserted into |
- | | | | |the payphone |
- |-------------------|-------------------|--------------------|-----------------|----------------|
- |Acknowledgement |Follows dialled |0 dBm to -37 dBm. |1600 Hz ▒ 50 Hz |0.5 s to 1.5 s |
- |Tone |access code | | | |
- | |(e.g.144) and | | | |
- | |precedes automatic | | | |
- | |voice prompt | | | |
- | |instructions | | | |
- |-------------------|-------------------|--------------------|-----------------|----------------|
- |Confirmation Tone |Used in some |0 dBm to -37 dBm. |1400 Hz |20 s followed by|
- | |exchanges in place | | |silence |
- | |of an announcement | | | |
- | |to indicate that an| | | |
- | |interrogated | | | |
- | |service is active | | | |
- |-------------------|-------------------|--------------------|-----------------|----------------|
- |Switching Tone |Used in some |0 dBm to -37 dBm. |400 Hz |0.2 s ON. |
- | |exchanges in place | | |0.4 s OFF. |
- | |of am announcement | | |2.0 s ON. |
- | |to indicate that an| | |0.4 s OFF. |
- | |interrogated | | | |
- | |service is not | | | |
- | |active | | | |
- +===============================================================================================+
-
- 3. NETWORK ANNOUNCEMENTS
- »»»»»»»»»»»»»»»»»»»»»»»»»»
- A variety of announcements may be returned to a user during call set-up
- and clear down. Other announcements may be returned to the user during
- set-up, operation and cancellation of supplementary services and
- services other than basic access to the Public Switched Telephone
- Network (PSTN) (eg. Chargecard, 0345, 0800, 0898)
- Some announcements will be preceded by Special Information Tone.
-
- All announcements will have a mean level at the BT network interface in
- the range -14 dBm to -28 dBm and will be repeated for between 1 and 5
- cycles.
-
-
-