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The SBC Core supports playing announcements, tones, and collecting digits.

Tone and Announcement Profile

Tones and announcements are configured by allocating a percentage of DSP cores to tones/announcements. If no transcoding is used, you may allocate up to 100% toward tones/announcements.

See  DSP Channel Densities for SBC 5000 and 7000 Series for a comparison of different DSP card configurations for SBC 5000 series and SBC 7000 series systems.

When using an external PSX, the PSX returns the tones/announcement profile and announcement or tone to be played in policy/trigger response. The SBCplays out the specified announcement/tone using the specified profile.

Announcement files are stored in the following directory:


When the SBC is configured to use an external PSX, there may be instances when hunt groups, or Automatic Call Distribution (ACD) groups, do not always operate as expected when the Tone and Announcement profile is used. A call can remain on hold even after answering the call. PSX 09.02.01R000 and later can be configured using the parameters End To End Ack and No CDR Change In End To End Ack to resolve this. End To End Ack must be enabled before enabling No CDR Change In End To End Ack flag. See PSX Manager User Guide for configuration details.

For more information on configuring tones and announcements, see following:

Tone Profile

The SBC supports a default tone package with a package ID of “1”. The default package contains the following default tone profile definitions.

  • defBusy
  • defCallWaiting1
  • defCallWaiting2
  • defCallWaiting3
  • defCallWaiting4
  • defCpeAlerting
  • defDial
  • defReorder
  • defRing
  • defSit1
  • defSit2
  • defSit3
  • fccBusy
  • fccDial
  • fccRingback

Tones are customized by provisioning tone packages and tone profiles. The tone profile feature supports tone generation methods as described in Table 1.

For details to configure tone profiles, see below:

Table : Tone Profile Generation Methods

Tone Type





Single Tone


0-3999 Hertz

(-50 to +3) dBm


Dual Tone

1, 2

0-3999 Hertz

(-50 to +3) dBm


Composite Tone

1, 2, 3, 4



  • Cadences to which each tone is applied
  • Decay time constant in milliseconds
  • Decay frequency delta in Hz/second
  • Decay tone bit map of tones against which decay/frequency rate change are applied

Modulated Tone


  • Carrier Frequency
  • Signal Frequency
  • Carrier Power
  • Signal Modulation Index


Local Ring Back Tones (LRBT)

The SBC Core is configurable to support Local Ring Back Tones as described below.

The SBC generates LRBT in the following conditions:

  • Start LRBT upon receipt of 180 without SDP, the SBC.
  • Halt LRBT upon receipt of any18x with SDP or any final response.
  • Stop LRBT without waiting for media packet arrival.

The SBC supports the following dynamic LRBT functionality related to RFC 3960:

  • Do not generate local ringing unless a 180 (ringing) response is received.
  • Generate local ringing if a 180 (ringing) is received but no incoming packets are present.
  • If a 180 (ringing) is received and incoming packets are present, play incoming packets but do not generate local ringing.

When configured to operate with an external PSX, local ring back tones are provisioned on the PSX on a per-trunk group basis. The PSX returns this information in a policy response.

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