The 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.
Announcements are customized by provisioning announcement packages using Media Profile on the . An announcement package supports provisioning of up to 16 announcement names to segment ID mapping. For more information on configuring Media Profiles, see Media Profile - CLI or Profile Management - Media Profiles.
When using an external PSX, the PSX returns the tones/announcement profile and announcement or tone to be played in policy/trigger response. The plays out the specified announcement/tone using the specified profile.
Announcement files are stored in the directory: /var/log/sonus/evlog/announcements
For more information on configuring tones and announcements, see following:
|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.
The supports a default tone package with a package ID of “1”. The default package contains the following default tone profile definitions.
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:
(-50 to +3) dBm
(-50 to +3) dBm
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
- Carrier Frequency
- Signal Frequency
- Carrier Power
- Signal Modulation Index
Local Ring Back Tones (LRBT)
The is configurable to support LRBT as described below:
The generates LRBT in the following conditions:
- Start LRBT upon receipt of 180 without SDP, the .
- Halt LRBT upon receipt of any18x with SDP or any final response.
- Stop LRBT without waiting for media packet arrival.
The supports the following dynamic LRBT functionality related to RFC 3960:
- Do not generate local ringing unless a 180 ringing response with SDP is received.
- Generate local ringing if a 180 ringing is received but no incoming media packets are present from the UAS.
- If incoming media packets are received from the UAS, play incoming packets and stop playing the tone.
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.
In a pass-through call scenario, the is prevented from selecting the preferred codec of the ingress offer to play the LRBT. The ingress offer codec may differ from the early answer codec that is used for the end-to-end cut-through, and this change in codec can cause a media glitch to the ingress user. The instead plays the LRBT with the same codec as the early answer codec that was received from egress (see the following call flow). The end-to-end cut-through also uses the codec that plays the LRBT. The codec used between early media and to play tones therefore remains consistent.
The call flow has the following configurations:
- UAC and UAS supports PCMU and PCMA
- Honor Remote Precedence is Enabled
- LRBT is enabled
In a transcode call scenario, the selects the preferred codec of the ingress offer to play the LRBT because there is no common codec between ingress and egress.
Playing Tones as Announcements
The SBC Core supports playing announcements that are stored in G.711ULaw format. The SBC Core is enhanced to support playing compressed tones directly without allocating DSP resources by playing the tones from the pre-encoded files with various combinations of tones and codec types. The tone files are created for the required tone types with different codec combinations and stored as
.wav files in the SBC. All these tones are stored with a ptime of 20 milliseconds.
The SBC Core includes the media profile
tonesAsAnnouncement which uses the following parameters to configure the announcement file to play LRBT for each codec entry:
The existing Tone Profile references the
toneType in the
tonesAsAnnouncement profile, whereas the new object
toneCodecEntry references the
codecType. With this enhancement, the user can associate default Tone Profile or can create a customized Tone Profile and assign it to the
toneType of the
toneAsAnnouncementProfile. The flag
announcementBasedTones is included in
toneAndAnnouncementProfile configuration to play LRBT without using DSP resources.
The SBC supports playing tones for seven groups of codecs. If the required tone playback falls under one of the following codecs and the flag
annoucementBasedTones is enabled, the SBC must avoid allocating DSP resources and play a tone as an announcement. If the required tone playback does not fall under one of the following codecs and the flag
annoucementBasedTones is enabled, the SBC does not fall back to the DSP mode and continues the call without playing the tones.
- G.711 (G.711ALaw and G.711ULaw)
- EVRC (EVRC, EVRC0, EVRCB, and EVRCB0)
- amrwbBandwidthEfficient (AMR-WB-BWE, 9 variants)
amrwbOctetAligned (AMR-WB-OA, 9 variants)
amrBandwidthEfficient (AMR-NB-BWE, 8 variants)
amrOctetAligned (AMR-NB-OA, 8 variants)
The SBC supports playing default ringtones with 41 different types of codec variants.
The compressed tone files are stored in the standard
.wav file format. The SBC uses the same naming convention for the compressed tone files as the announcement files. For example, in a
sDDDDD.wav file, where DDDDD is a decimal number from 1 to 65,535, the decimal number represents the segment ID of the file.
The announcement and the tone files share the 5-bit segment ID space, and thus, every file name must have a unique segment ID. The compressed tone files are stored in the same directory path as the announcement files
/var/log/sonus/sbx/announcements). The tone file is played continuously until the tone is stopped due to a trigger.
The following table provides the
.wav file mapping information for the application announcements:
|File Name||Announcement ID||RBT||Audio Message|
|20001||RBT_MULAW||US Ring Back Tone|
|s20002.wav||20002||RBT_ALAW||US Ring Back Tone|
|s20003.wav||20003||RBT_EVRC (interleaved mode)||US Ring Back Tone|
|s20004.wav||20004||RBT_EVRCB (interleaved mode)||US Ring Back Tone|
|s20005.wav||20005||RBT_AMRWBBE_6_6K||US Ring Back Tone|
|s20006.wav||20006||RBT_AMRWBBE_8_85K||US Ring Back Tone|
|s20007.wav||20007||RBT_AMRWBBE_12_65K||US Ring Back Tone|
|s20008.wav||20008||RBT_AMRWBBE_14_25K||US Ring Back Tone|
|s20009.wav||20009||RBT_AMRWBBE_15_85K||US Ring Back Tone|
|s20010.wav||20010||RBT_AMRWBBE_18_25K||US Ring Back Tone|
|s20011.wav||20011||RBT_AMRWBBE_19_85K||US Ring Back Tone|
|s20012.wav||20012||RBT_AMRWBBE_23_05K||US Ring Back Tone|
|s20013.wav||20013||RBT_AMRWBBE_23_85K||US Ring Back Tone|
RBT_EVRC0 (Header free packet mode)
|US Ring Back Tone|
|s20015.wav||20015||RBT_EVRCB0 (Header free packet mode)||US Ring Back Tone|
|s20016.wav||20016||RBT_AMRWBOA_6_6K||US Ring Back Tone|
|s20017.wav||20017||RBT_AMRWBOA_8_85K||US Ring Back Tone|
|s20018.wav||20018||RBT_AMRWBOA_12_65K||US Ring Back Tone|
|s20019.wav||20019||RBT_AMRWBOA_14_25K||US Ring Back Tone|
|s20020.wav||20020||RBT_AMRWBOA_15_85K||US Ring Back Tone|
|s20021.wav||20021||RBT_AMRWBOA_18_25K||US Ring Back Tone|
|s20022.wav||20022||RBT_AMRWBOA_19_85K||US Ring Back Tone|
|s20023.wav||20023||RBT_AMRWBOA_23_05K||US Ring Back Tone|
|s20024.wav||20024||RBT_AMRWBOA_23_85K||US Ring Back Tone|
|s20025.wav||20025||RBT_AMRNBBE_4_7K||US Ring Back Tone|
|s20026.wav||20026||RBT_AMRNBBE_5_9K||US Ring Back Tone|
|s20027.wav||20027||RBT_AMRNBBE_5_15K||US Ring Back Tone|
|s20028.wav||20028||RBT_AMRNBBE_6_7K||US Ring Back Tone|
|s20029.wav||20029||RBT_AMRNBBE_7_4K||US Ring Back Tone|
|s20030.wav||20030||RBT_AMRNBBE_7_95K||US Ring Back Tone|
|s20031.wav||20031||RBT_AMRNBBE_10_2K||US Ring Back Tone|
|s20032.wav||20032||RBT_AMRNBBE_12_2K||US Ring Back Tone|
|s20033.wav||20033||RBT_AMRNBOA_4_7K||US Ring Back Tone|
|s20034.wav||20034||RBT_AMRNBOA_5_9K||US Ring Back Tone|
|s20035.wav||20035||RBT_AMRNBOA_5_15K||US Ring Back Tone|
|s20036.wav||20036||RBT_AMRNBOA_6_7K||US Ring Back Tone|
|s20037.wav||20037||RBT_AMRNBOA_7_4K||US Ring Back Tone|
|s20038.wav||20038||RBT_AMRNBOA_7_95K||US Ring Back Tone|
|s20039.wav||20039||RBT_AMRNBOA_10_2K||US Ring Back Tone|
|s20040.wav||20040||RBT_AMRNBOA_12_2K||US Ring Back Tone|
|s20041.wav||20041||RBT_G722||US Ring Back Tone|
.wav files for tones other than g711 a and u law are in Sonus proprietary format.
LMSD - Tone Play Support
The SBC supports playing tones when an Alert-Info (AI) header is received in the Legacy Mobile Station Domain (LMSD) format (Alert-Info: <http:/LMSD/tone?sig-id=rt>). The SBC is enhanced to play the LRBT without using DSP resources whenever it receives 180 with Session Description Protocol (SDP) answer with AI header (Alert-Info: <http:/LMSD/tone?sig-id=rt>). The Al header, present in the 180 ringing with SDP, carries the tone package information required by the SBC to play LRBT. To support this feature, the existing LRBT framework is enhanced.
The SBC supports generating LRBT when:
- The flag
acceptAlertInfo is enabled on the egress TG.
- The provisional response is 180 ringing with SDP and the tone flavor is normal.
- The P-Com.DropEarlyMedia header is not present in the original INVITE.
- The SDP answer is received in 180 or in a previous provisional response (183).
- The 180 contains an AI header having sig-id = “rt” only (bt/ct does not play tone).
- The flag
announcementBasedTone in the
toneAndAnnouncementProfile associated with the ingress TG is enabled.
The SBC supports fallback to LMSD inter-working state, if the flag
acceptAlertInfo is enabled and the playing tone is failed. If the flag
acceptAlertInfo is not enabled, the SBC continues to process the call without playing a tone.
LMSD - Playing Tones Using Lock Down Preferred Codec
The SBC plays tones using the “lock down" preferred codec when the following flags are enabled:
The codec that is used for playing tone towards the ingress leg is based on whether the session is established as pass-through or transcoded. If the SBC receives SDP answer from the egress peer, the selected codec is the egress peer's preferred codec. However, the ingress peer's preferred codec is used to play the tone, if the session outcome is transcoding.
The SBC plays tones when it receives 180 responses with SDP for the egress peer preferred codec. When the 180 response is received without SDP from the egress peer, the SBC plays LRBT based on the existing LRBT implementation using the ingress peer preferred codec.
LMSD - Handling UPDATEs for the Tones
The SBC is enhanced to stop playing LRBT upon receipt of any of the following messages:
- UPDATE message with different SDP
- subsequent 183 with SDP
- 200 OK with or without SDP
For more information on Tone and Announcement feature, refer to:
Alert-Info and P-Early Media Headers Interworking
The SBC supports the following AI to PEM interworking functionality using the flag
- Interworking between a network supporting AI header (based on the Legacy Mobile Station Domain (LMSD) format) to a network supporting PEM header. The SBC supports interworking irrespective of the existence of a provisioned tone on the SBC.
- Interworking between a network that does not support PEM header to a network that supports PEM header. For example, the ingress network supports PEM header; however, the egress network does not.
- Interworking between networks that support PEM headers.
Tone playing is not dependent upon AI and PEM headers interworking.
When a tone is configured on the SBC,
- If the flag
aiToPemInterworking is disabled, the SBC plays tone based on the LMSD format. For more information, refer to Tones and Announcements.
If the flag
aiToPemInterworking is enabled, the SBC supports interworking between AI and PEM headers. The SBC plays tone when it receives AI header with sig-id=rt in the 180 provisioning response (either first 180 response or subsequent 180 response) from the Mobile Switching Center (MSC) (CDMA network).
When all the tone playing criteria are fulfilled, the SBC inserts PEM header as SENDRECV (PEM: SENDRECV) and sends it towards the ingress network.
When the SBC fails to play tone, the SBC inserts PEM header as INACTIVE (PEM: INACTIVE) and sends it towards the ingress network.
When tone is not configured on the SBC; and the IPSP flag
acceptAlertInfo is enabled on the egress TG, and the INVITE message is received with PEM: SUPPORTED,
P-Early Media to Alert-Info Header Interworking
The SBC supports interworking between a network supporting PEM header to a network supporting Al header. To support this functionality, the flag
aiToPemInterworking is used in the IP Signaling Profile. The SBC performs PEM to AI interworking once the 180 response is received with PEM header, while forwarding 180 response. If the peer does not explicitly provide early media authorization using a PEM header in 180 response with SDP answer, the SBC monitors the RTP traffic from the egress TG and performs a cut-through if RTP is received from the egress. To support this functionality, the flag
monitorRTP is added to the SIP Trunk Group.
In case of PEM to AI interworking, the PEM must be supported on the egress leg.
Interworking between PEM and AI Headers
The SBC supports PEM to AI interworking when PEM header is supported on the Trunk Group towards which 180 provisional response message is received and
acceptAlertInfo flag is enabled on the Trunk Group towards which 180 provisional response message is sent.
PEM to PEM Interworking
The SBC supports PEM to PEM interworking when PEM header is supported on the Trunk Group towards which 180 provisional response message is received and PEM is supported on the Trunk Group towards which 180 provisional response message is sent.
- When the SBC is not configured to play tone:
- if the SBC receives 180 response with PEM header, while forwarding 180 response, the SBC relays the received PEM header towards ingress.
- if the SBC does not receive PEM header, the SBC inserts PEM header based on the SDP direction in 180 provisional response while forwarding 180 response towards ingress.
- if the SBC does not receive PEM header and the flag
monitorRTP is enabled, the SBC forwards 180 response without PEM and monitors RTP.
- When the SBC is configured to play tone:
- if the SBC receives an inactive PEM, the SBC inserts PEM sendrecv while forwarding 180 response towards ingress.
- if the SBC does not receive PEM and the flag
monitorRTP is enabled, the SBC inserts PEM sendrecv provided any of the previous provisional response did not receive PEM while sending 180 response towards ingress.
- if the SBC receives PEM with sendrecv/sendonly, the SBC does not play tone and relays the received PEM header towards ingress.
The SBC monitors the RTP packets when all or either of the following conditions are met.
- when the SBC sends an INVITE with PEM=supported and an early media SDP answer (in any 18x response) is received without PEM header.
- when the flag
defaultGatingMethod is set as
none. For more information on the flag
defaultGatingMethod, refer to SIP Trunk Group - Media - CLI.
Playing Tone Locally
The SBC is enhanced to play LRBT locally without considering PEM header. To achieve this functionality, the flag
withOrWithOutSdp is added to the
The SBC plays tone locally when it receives:
- first 180 response without SDP and PEM header or with PEM=inactive.
- first 180 response with SDP and PEM=inactive.
- first 180 response with SDP is received without PEM header.
- subsequent 180 responses without SDP and PEM header and the previous provisional response does not contain PEM header (even during an RTP monitoring).
- subsequent 180 responses without SDP with PEM=inactive.
- subsequent 180 responses with SDP and without PEM header or PEM=inactive and the previous provisional response does not contain PEM header (even during an RTP monitoring).
- The SBC does not play tone when 180 without SDP and PEM is received when a previous 18x response had PEM=sendrecv/sendonly.
- The flag
withOrWithOutSdp is not available for Forced and Dynamic LRBT flavors.
SBC does not Stop Playing Tone when UPDATE is Received from the UAS
The SBC is enhanced to continue playing the ringback tone after receiving an UPDATE message from the User Agent Server (UAS), rather than stopping the tone. The SBC then monitors the egress leg, stops the tone, if it receives an RTP packet or 200 OK message and opening the audio path in both directions. The UAS sends an UPDATE message, a codec upgrade, or a media hold. If the UPDATE message is due to a codec upgrade, the SBC continues playing the ringback tone using the new codec. If the SBC is not configured to continue playing the ringback tone after UPDATE, the caller may hear a very short ringback tone followed by a long period of silence until the final response is received. To achieve this functionality, the flag
monitorRtpOnEgressUpdate is added to the
egressIpAttributes of the IP Signaling Profile.
The SBC supports early media authorization in UPDATE, 200 OK to UPDATE, and PRACK messages towards the Trunk Group that supports PEM.
- if PEM is received, the data path mode is set based on intersection of the SDP direction attribute and PEM header received.
- if PEM is not received in the egress UPDATE, the SBC relays the UPDATE towards the ingress without PEM.
- if PEM is not received in 200 OK (UPDATE), the SBC does not add PEM header. It only adds PEM header in the 200 OK if UPDATE is received from the ingress with PEM: inactive or without PEM and the SBC is configured to play the tone.
- The SBC receives and processes:
UPDATE without PEM and forwards UPDATE without PEM header, when SBC is not playing tone.
UPDATE without PEM and forwards UPDATE with PEM=sendrecv header, when SBC is playing tone (when RTP monitoring is configured).
- if UPDATE is received on a leg, on which tone is being played, UPDATE is locally handled and tone is played with the new codec.
- The SBC receives and processes:
- 200 OK to UPDATE with PEM and relays 200 OK to UPDATE with PEM header.
- The SBC processes the PEM header received in:
- PRACK message and relays PRACK with PEM header.
- PRACK message and if PRACK message is received without PEM header, the SBC relays PRACK without PEM header.
- The SBC is configured to play tone:
- if UPDATE is received without PEM or PEM:inactive from egress, the SBC inserts UPDATE with PEM:sendrecv towards ingress.
- if UPDATE is received with sendrecv/sendonly/recvonly, the SBC relays UPDATE with PEM towards ingress.