In this section:
Overview
The Packet Service Profile supports up to four audio encoding entries, or Codecs, using ERE. The SBC Core will negotiate a Codec from the list of Codecs allowed in the Packet Service Profile. One example of a negotiation scenario occurs when a call comes into the SBC from an H.323 peer. The SBC preferred coding may be G.711, while the H.323 gateway at the far end may prefer G.729A coding because that gateway has limited bandwidth to access the IP network.
In order to properly handle a call compression negotiation such as that described above, it is necessary to examine the codec list on both the local and remote gateway to find one or more codecs that are common to both. The precedence of the resultant codecs is controlled by the local precedence setting, or the precedence of the remote peer. This provisioning directive is provided by the honorRemotePrecedence parameter.
Refer to Packet Service Profile Provisioning Examples for provisioning examples.
The PSX supports configuring up to 12 codecs in the Packet Service Profile and Preferred Packet Service Profile. The SBC supports receiving all 12 codecs from the PSX in the PSP and Preferred PSP. This applies to interworking with an external PSX (Advanced ERE deployment scenario). See Routing and Policy Management for deployment scenario details. Additionally, the SBC supports up to 12 codecs over Gateway links to SBCs and/or GSXs. An SBC-POL-RTU license is needed to enable more than four codecs.
Note
Note
Note
Avoid using both the Silence Suppression (SS) and non-SS variant of the same codec in one Packet Service Profile (PSP) because doing so can lead to extra offer-anwer handshakes and trigger a race condition while the SBC attempts to identify a common codec instead of simply transcoding the call.
Example using G.729A on the ingress trunk group, and using G.729AB on the egress trunk group to avoid this situation:
- Ingress PSP: 711, 729A
- Egress PSP: 711, 729AB
- Transcode : Conditional
- Conditions In Addition To No Common Codec : Different Silence Suppression,
- Ingress This Leg: 711, 729
- Egress This Leg: 711, 729
Audio Transparency
The SBC Core supports audio transparency in relaying unknown attributes and a subset of known attributes, such as rtpmap, fmtp, and T38 fax. The SBC also manages bandwidth for audio streams in pass-through calls. Audio transparency is controlled by the following PSP and Trunk Group parameters/flags.
Packet Service Profile:
Enable
transcoderFreeTransparencyfor the session (enable on either of the PSPs)Configure
audioTransparencysettingsEnable/disable
reserveBwForPreferredAudioCommonCodec
SIP Trunk Group:
Enable
sdpAttributesSelectiveRelayon both ingress and egress Trunk Groups that receive the relayed SDP
Refer to SBC SIP Transparency Implementation Guide for transparency implementation details.
IMPORTANT
Ribbon recommends using the Transparency Profile to configure transparency on the SBC Core for new deployments, as well as applying additional transparency configurations to existing deployments. Do not use IP Signaling Profile flags in these scenarios because the flags will be retired in upcoming releases.
Refer to the SBC SIP Transparency Implementation Guide for additional information.
Granular Control of HD Codecs in Offers or Answers
Both the SBC ERE and PSX provide control over HD codec prioritization through Packet Service Profile options. ERE functionality is described in this section. The following SBC flags are configurable in the Packet Service Profile to control HD codec prioritization:
Packet Service Profile
Command Syntax
% set profiles media packetServiceProfile <unique_profile_name>
aal1PayloadSize <0-999>
audioTransparency <unknownCodecBitRate | unknownCodecPacketSize>
codec <codecEntry1-codecEntry12> <codec>
dataCalls
initialPlayoutBufferDelay <5-50>
packetSize <10 | 20 | 30 | 40>
preferredRtpDataPayloadType <0-127>
dtls
dtlsCryptoSuiteProfile <profile name>
dtlsFlags
allowDtlsFallback <disable | enable>
dtlsSctpRelay <disable | enable>
dtlsSrtpRelay <disable | enable>
enableDtlsSrtp <disable | enable>
flags
g711T140BaudotAdapt <disable | enable>
honorRemotePrecedence <disable | enable>
mediaPacketCos <0-7>
nonRtpStream
maxNonRtpBandwidth <0-8000>
nonRtpTlsProfileName <TLS profile name>
packetToPacketControl
peerAbsenceAction <none | peerAbsenceTrap | peerAbsenceTrapAndDisconnect>
preferredRtpPayloadTypeForDtmfRelay <0-128>
qosValues
applicationDscp <0-63>
dtlsSctpDscp <0-255>
msrpDscp <0-255>
t140Dscp <0-63>
rtcpOptions rtcp <disable | enable>
secureRtpRtcp
cryptoSuiteProfile <profile_name>
flags
allowFallback <disable | enable>
allowPassthru <disable | enable>
enableSrtp <disable | enable>
resetEncDecROCOnDecKeyChange <disable | enable>
resetROCOnKeyChange <disable | enable>
updateCryptoKeysOnModify <disable | enable>
sendRoutePSPPrecedence <disable | enable>
silenceFactor <0-50>
silenceInsertionDescriptor
g711SidRtpPayloadType <0-127>
heartbeat <disable | enable>
t38
dataRateManagementType <type1LocalGenerationOfTcf | type2TransferOfTcf>
ecm ecmPreferred <disable | enable>
lowSpeedNumberOfRedundantPackets <0 | 1 | 2>
maxBitRate <2.4Kbits_s | 4.8Kbits_s | 9.6Kbits_s | 14.4Kbits_s>
numberOfRedundantPackets <0 | 1 | 2>
protocolVersion <0 | 3>
typeOfService <0-255>
videoCalls
audioOnlyIfVideoIsPrevented <disable | enable>
codecListProfile <name>
ieee8021QVLanCos <0-7>
ipv4Tos <0-255>
ipv6TrafficClass <0-255>
maxVideoBandwith <0-50000 kbps>
videoBandwidthReductionFactor <0-100>
voiceInitialPlayoutBufferDelay <1-200 ms>
Command Parameters
The Packet Service Profile parameters are described below:
Packet Service Profile Parameters
Parameter | Length/Range | Description |
|---|---|---|
| N/A | Specifies a unique identifier (name) for packet service profile. You can define any name or use Default as the parameter. |
| 0-999 | The ATM Adaption Layer Type 1 (AAL-1) payload size (default = 47). |
audioTransparency | N/A | Use this object to configure Audio Transparency settings.
NOTE: If the bandwidth is not configured, the |
| codecEntry1-codecEntry12 |
Up to 12 codec configurations are supported by the SBC for PSX, and Advanced ERE deployment scenarios (refer to Routing and Policy Management for a description of the different routing configurations). |
| N/A | Data calls pertaining to restricted or unrestricted digital data.
|
dtls | N/A | Use this object to control DTLS-SRTP and DTLS fall-back behavior in this Packet Service Profile.
NOTE: DTLS-SRTP relay is a licensed feature and requires an SRTP license to be installed on the SBC. NOTE: When a session contains DTLS-SRTP video stream or DTLS/SCTP application stream and there is no audio stream specified, the SBC allows the session when the ingress and egress Packet Service Profiles (PSP) are configured as audio pass-through. If ICE is part of session establishment in WebRTC (WRTC) scenario, the relay mechanism implemented for DTLS-SRTP and DTLS/SCTP is supported independent of ICE processing. Refer to Configuring SBC for WRTC for additional WebRTC configuration details. |
| N/A | See Packet Service Profile Flags table below for flag descriptions. |
| N/A | This flag sends the indication in a D+ response to allow text transcoding when G711, G722 and/or OPUS are selected as the codec along with T140 stream.
This flag only affects the behavior for G.711-G.711 calls for which one leg has T.140 (one m-line with T.140) with a valid port. |
| N/A | Flag to set precedence of audio encoding priority order of the local packet service profile over the remote peers audio encoding priority order when creating the priority order of the audio encodings that are common to both. Options are:
|
| 0-7 | Specifies Class of Service (COS) value to be set in the IEEE 802.1D User Priority field of media packets transmitted on a call leg that uses this Packet Service Profile. This parameter only has an effect if the network interface supports 802.1Q tagged Ethernet frames. (default = 0 which is interpreted as best effort). |
nonRtpStream | N/A | Use this object to configure options that apply to non-RTP media streams.
|
| N/A | Use this object to define the packet-to-packet control parameters. See Packet to Packet Control Parameters table below for details. |
| N/A | Specifies the action to take when
|
preferredRtpPayloadTypeForDtmfRelay | 0-128 | Specifies the preferred RTP payload type in the RTP header of audio packets for this encoding. (default = 128). This parameter is only used for 8 kHz clock rate. DTMF payload type of each subsequent clock rate (16 kHz, 24 kHz, etc.) is incremented by 1. NOTE: Using the default value of "128" for NOTE: If NOTE: The SBC uses the For wideband (16 kHz) DTMF, the SBC uses the next available payload type (to the configured |
qosValues | N/A | Use this object to configure the Quality of Service (QoS) DSCP value for this Packet Service Profile.
|
| N/A | Use this object to specify Real Time Control Protocol (RTCP) options for the call. RTCP is used to report network traffic congestion data. Various actions (for example call disconnect) may be taken when congestion threshold settings are exceeded. See RTCP Options Parameters table below for details. |
| N/A | Specifies whether secure RTP Real Time Control Protocol (SRTP) is enabled for the call:
|
| N/A | Use this flag to allow audio encoding order preference in outgoing messages only.
|
| N/A | The percentage of call time that silence is expected. This parameter is used to reduce expected call bandwidth. (range: 0-50 / default = 40). |
| N/A | Use this object to define the Silence Insertion Descriptor (SID) attributes.
|
| N/A | Use this object to specify T.38 data rate attributes using following parameters:
|
| 0-255 | Use this object to set the six most significant bits of the "Type of Service" byte in the IP header. Default value is 0. |
| N/A | Use this object to define video call parameters.
|
| 1-200 | Use this parameter to configure the initial playout buffer delay value (in milliseconds). Select a value just slightly greater than the maximum expected packet jitter across the network.The value must be in increments of 1 ms. (default = 10). NOTE: Using a value above 50 ms is not recommended during normal operation. |
SBC Core Behavior For T.38 version=0, the SBC supports four bit rates: 2.4 Kbps, 4.8 Kbps, 9.6 Kbps and 14.4 Kbps. The SBC normalizes the T.38 bit rate that it receives in the SDP from the peers. External PSX Provisioning Another configuration related to T.38 Max Bit Rate handling for non-Direct Media calls is the PSX "Use Max Bit Rate Only" object, with the following considerations:T.38 Max Bit Rate Handling for Non-Direct Media Calls
Consequently, the SBC uses the minimum value of: route-configured bit rate and peer's bit rate after normalization.
Examples:
Codec
Command Syntax
% set profiles media packetServiceProfile <unique_profile_name> codec <codecEntry1-codecEntry12> <codec name>
Command Parameters
Note
SBC-POL-RTU license is needed to enable more than four codecs.
Codec Parameters
| Parameter | Description |
|---|---|
codecEntry1 <codec name> | Codec entry with a priority of "1" |
codecEntry2 <codec name> | Codec entry with a priority of "2" |
codecEntry3 <codec name> | Codec entry with a priority of "3" |
codecEntry4 <codec name> | Codec entry with a priority of "4" |
codecEntry5 <codec name> | Codec entry with a priority of "5" |
codecEntry6 <codec name> | Codec entry with a priority of "6" |
codecEntry7 <codec name> | Codec entry with a priority of "7" |
codecEntry8 <codec name> | Codec entry with a priority of "8" |
codecEntry9 <codec name> | Codec entry with a priority of "9" |
codecEntry10 <codec name> | Codec entry with a priority of "10" |
codecEntry11 <codec name> | Codec entry with a priority of "11" |
| Codec entry with a priority of "12". |
For each codecEntry ID, choose a Example default codec names are:
| |
Flags
Command Syntax
% set profiles media packetServiceProfile <unique_profile_name> flags
HDCodecPreferred <disable | enable>
MatchOfferedCodecGroupIfNbOnly <disable | enable>
allowAudioTranscodeForMultiStreamCall <disable | enable>
allowMidCallSSRCModification <disable | enable>
digitDetectSendEnabled <disable | enable>
disallowDataCalls <disable | enable>
dscpPassthrough <disable | enable>
forceRoutePSPOrder <disable | enable>
generateAndSignalSSRCAndCname <disable | enable>
interworkDtmfWithoutTranscoding <disable | enable>
preferNBPassthruOverHDTranscode <disable | enable>
reserveBwForPreferredAudioCommonCodec <disable | enable>
ssrcRandomize <disable | enable>
ssrcRandomizeForSrtp <disable | enable>
t140Call <disable | enable>
useDirectMedia <disable | enable>
validatePeerSupportForDtmfEvents <disable | enable>
Command Parameters
Packet Service Profile Flags
| Parameter | Description | ||||||||||||||||||||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
HDCodecPreferred | Enable flag to set HD codecs as preferred codec over non-HD codecs even if transcoding is required. When flag is disabled, continue with existing PSP/IPSP behavior.
When enabled, the following behavior is exhibited:
Codec selection priority from Answer message:
NOTE: This flag only applies when the SBC is configured with an external PSX. NOTE: If NOTE: The flag | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| Enable this flag to allow the SBC to send only NB in outgoing offer if only NB is received in the ingress offer. Otherwise, do nothing. While sending the offer, this flag becomes is ignored if either HD-only or (HD+NB) is received in incoming offer. If this flag is disabled, the SBC uses existing behavior.
NOTE: The flag | ||||||||||||||||||||||||||||||||||||||||||||||||||||
allowAudioTranscodeForMultiStreamCall | Use this flag to specify whether or not to allow audio transcoding when a session contains other media streams, such as a video stream. Options are:
| ||||||||||||||||||||||||||||||||||||||||||||||||||||
| Enable this flag so that in call hold/resume scenarios the SBC modifies the SSRC and associated attributes after the call resumes. The SBC sends both the previous and updated SSRC in SDP signaling and includes the new SSRC iin RTP/RTCP streams. Options are:
Note: You must enable the Note: If you enable the IP Signaling profile common IP attributes flag | ||||||||||||||||||||||||||||||||||||||||||||||||||||
digitDetectSendEnabled | Enable this flag to allow digit detection for pass-through calls on digits sent to the network.
NOTE: Enable this flag to allow interworking without DSP resources for this Packet Service Profile. INFO: See Digit Detect Send Enabled Settings for KPML table below to understand which PSP leg to enable this flag for the desired KPML functionality. | ||||||||||||||||||||||||||||||||||||||||||||||||||||
disallowDataCalls | Enable flag to disallow data calls.
| ||||||||||||||||||||||||||||||||||||||||||||||||||||
dscpPassthrough | When enabled on both the Ingress and Egress call leg, the DSCP value in the IP header of the media packets is transparently passed through the system. Once media is received from the peer, any value set in the
| ||||||||||||||||||||||||||||||||||||||||||||||||||||
| Enable this flag to send the outgoing offer in the same order as egress route Packet Service Profile irrespective of HD/NB priorities.
NOTE: If this flag is enabled, HDCodecPreferred flag does not affect the ordering of outgoing offer. NOTE: The flag | ||||||||||||||||||||||||||||||||||||||||||||||||||||
generateAndSignalSSRCAndCname | Enable this flag to generate an SSRC value and associated attributes and include them in SDP signaling and RTP/RTCP streams. Options are:
Note: This flag takes precedence over the Packet Service Profile | ||||||||||||||||||||||||||||||||||||||||||||||||||||
interworkDtmfWithoutTranscoding | Enable flag to interwork DTMF with out-of-band RFC2833 without the use of transcoding (DSP resources).
NOTE: If | ||||||||||||||||||||||||||||||||||||||||||||||||||||
mediaLockDownForPassThrough | This flag is deprecated. | ||||||||||||||||||||||||||||||||||||||||||||||||||||
policeOnHeaviestAudioCodec | When enabled, the SBC reserves the worst case common codec bandwidth on trunk groups and interfaces, but polices on maximum bandwidth for all codecs from Offer or Answer in a pass-through call.
NOTE: This configuration applies to all pass-through calls. It works independently from the Audio Transparency feature and | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| Enable this flag to allow the SBC to choose NB-NB pass-through over HD-HD transcoded call. When disabled, the SBC prefers HD-HD transcoded call over NB-NB pass-through.
NOTE: This flag is valid only if NOTE: The flag | ||||||||||||||||||||||||||||||||||||||||||||||||||||
reserveBwForPreferredAudioCommonCodec | By default, the SBC reserves the worst case common audio codec bandwidth for pass-through calls on trunk groups and IP interfaces, and polices the same bandwidth. Use this flag to reserve the bandwidth associated with the preferred common codec and police on the worst case codec. This flag applies to both known and unknown codecs, and can be used independently or in conjunction with Audio Transparency feature.
NOTE: This flag is active for a call when both the PSPs have this flag enabled. If this flag is disabled in any of the PSPs, the flag is not applied. | ||||||||||||||||||||||||||||||||||||||||||||||||||||
ssrcRandomize | Enable this flag to generate a new synchronization source (SSRC) using a random value along with a new timestamp on a new RTP stream whenever reactivating a resource (due to a change in codec or some other event). SSRC randomization reduces the probability of collision in large groups and simplifies the process of group sampling that relies on a uniform distribution of SSRCs. This flag also affects medial behavior following a switchover.
Options:
| ||||||||||||||||||||||||||||||||||||||||||||||||||||
ssrcRandomizeForSrtp | Enable this flag to determine how the SBC handles SSRCs in SRTP media flows. When enabled, the SBC:
When disabled, the SBC relays the SSRC for pass-through media flows it receives from the peer.
| ||||||||||||||||||||||||||||||||||||||||||||||||||||
t140Call | Enable flag to allow text media calls using T.140 codec.
NOTE: The SBC does not validate, prioritize, or purge any codec or attributes received for the text media. Any required validation is performed by the endpoints. Refer to Text Codecs for additional details of text codec support. Behavior of Audio+Text Call:
For a text only call:
| ||||||||||||||||||||||||||||||||||||||||||||||||||||
useDirectMedia | Enable flag to use direct media as needed.
| ||||||||||||||||||||||||||||||||||||||||||||||||||||
| Flag to validate peer support for DTMF events. Enable this flag for all peer devices that support RFC 4733.
|
Digit Detect Send Enabled Settings for KPML
Use the following table for guidance in setting the Digit Detect Send Enabled flag on each PSP leg to achieve the desired Key Press Markup Language (KPML) functionality. Refer to KPML DTMF Support section on the page DTMF and RTP Relay for feature details. Digit Detect Send Enabled Settings for KPML
Info
Ingress PSP Egress PSP KPML Subscription Leg Enable Enable Egress / Ingress Disable Enable Egress / Ingress with stream reverse Enable Disable Ingress / Egress with stream reverse Disable Disable None
Packet to Packet Control
Command Syntax
% set profiles media packetServiceProfile <unique_profile_name> packetToPacketControl codecsAllowedForTranscoding otherLeg <amr | efr | evrc | g711a | g711u | g722 | g726 | g729 | g7221 | g7222 | g7231 | ilbc | l16 | opus | t38> thisLeg <amr | efr | evrc | g711a | g711u | g722 | g726 | g729 | g7221 | g7222 | g7231 | ilbc | l16 | opus | t38> conditionsInAdditionToNoCommonCodec applyFaxToneTreatment <disable | enable> different2833PayloadType <disable | enable> differentDtmfRelay <disable | enable> differentPacketSize <disable | enable> differentSilenceSuppression <disable | enable> honorAnswerPreference <disable | enable> honorOfferPreference <disable | enable> transcode <conditional | determinedByPspForOtherLeg | only | transcoderFreeTransparency>
Command Parameters
Packet to Packet Control Parameters
| Parameter | Description |
|---|---|
codecsAllowedForTranscoding | Use this parameter to specify codecs allowed for transcoding, and which leg to apply them to.
Codec list: amr | efr | evrc | g711a | g711u | g722 | g726 | g729 | g7221 | g7222 | g7231 | ilbc | l16 | opus | silk | t38 |
conditionsInAdditionToNoCommonCodec | The SBCperforms transcoding when any of the specified conditions are met, including no common codec on ingress and egress legs.
|
transcode | Transcode options:
NOTE: If using Transcoder Free Transparency option " NOTE: Transcoder Free Transparency takes precedence over Packet Service Profile flags when enabled on either the ingress trunk group or egress trunk group PSP leg allowing the SBC to bypass transcoding and codec policies that result in removing/deleting codecs. |
NOTE: The SBC, when configured with the appropriate codecs, transcodes for differences in the codecs. Use ‘transcode conditional’ option to allow the SBC to transcode for certain conditions in addition to differences in codecs. For example, if the codecs are the same on both legs and this option is selected, by applying additional settings for the particular call scenarios, the SBC will trigger transcoding for those scenarios, such as:
- Transcode for DTMF differences. For example, when both legs have same codec, but one uses in-band for DTMF and the other RFC 2833.
- Transcode for Silence Suppression differences.
- Transcode for Packet Size differences.
- Transcode for RFC2833/4733 Payload differences. For example, when codecs are the same on both legs, but one side uses 101 as the Payload Type for DTMF and the other uses 102.
- Transcode always.
honorAnswerPreference vs. honorOfferPreference
| HOP Flag State | HAP Flag State | SBC Behavior |
|---|---|---|
| enable | disable | The SBC selects a codec order of precedence in the offered SDP, irrespective of whether it is a pass-through or transcoded codec (if transcoding is defined for that codec). The SBC as part of media lock-down may send a re-INVITE to egress peer. Note that the preference on the answer side is given to a pass-through codec. |
| enable | enable | The SBC gives preference to HAP over HOP in case of conflict. The Honor Remote Preference (HRP) flag on the answer leg decides the preference order. Based on that preference list, the SBC selects a codec with highest preference from answer SDP that can be used even if it requires transcoding. Note that this may cause the selection of a codec on the other side leg not to be honored. This happens in case of a pass-through call. |
| disable | enable | The SBC gives preference to answer codec order that is created based on HRP flag. The most preferred codec is chosen as received in the answer SDP, irrespective of whether it is a pass-through or a transcoded codec (if transcoding is defined for that codec). |
RTCP Options
Command Syntax
% set profiles media packetServiceProfile <unique_profile_name> rtcpOptions rtcp <disable | enable>
enableRTCPForHeldCalls <disable | enable>
generateRtcpForT140IfNotReceivedFromOtherLeg <disable | enable>
packetLossAction <none | packetLossTrap | packetLossTrapAndDisconnect>
packetLossThreshold <0, 400-32767>
rrBandwidth <100-4000>
rsBandwidth <100-3000>
rtcpMux <disable | enable>
rtcpXr <disable | relay | relayOrTerminate>
terminationForPassThrough <disable | enable>
Command Parameters
RTCP Options Parameters
| Parameter | Length/Range | Description |
|---|---|---|
rtcp | N/A | Enable flag to use RTCP for the call.
NOTE: The below attributes are only available to configure RTCP once this flag is enabled. |
enableRTCPForHeldCalls | N/A | If this flag is enabled, the SBC ignores the configured RR/RS values in the Packet Service Profile (PSP) and sends RR/RS = 0 in the offer/answer, plus disables RTCP when the call is active. When the call is HELD, and a re-INVITE is sent, the SBC uses the configured values in the PSP for RTCP bandwidth and enables RTCP. When the call is RESUMED, the SBC again disables RTCP by sending RR/RS=0 in the re-INVITE.
|
generateRtcpForT140IfNotReceivedFromOtherLeg | N/A | The SBC generates RTCP for T140 media streams if RTCP is not received from peer.
Note: To enable this parameter, ensure that the For more information, refer to Text Over IP (ToIP) and TTY Support. |
packetLossAction | N/A | Packet loss action to take when packet threshold is exceeded:
|
packetLossThreshold | 0, 400-32767 | Enter a value to specify the packet loss threshold value to trigger a packet loss action (default = 0). This parameter is required if RTCP is enabled. When set to “0”, no packet loss inactivity detection is performed. See Command Examples below for an example configuration. This setting can be used in conjunction with |
rrBandwidth | 100-4000 | <rrBandwidth value> – The RTCP bandwidth allocated to active data senders (default = 250). |
rsBandwidth | 100-3000 | <rsBandwidth_value> – The RTCP bandwidth allocated for receivers (default = 250). |
rtcpMux | N/A | Enable this flag for the ingress or egress Packet Service Profile for the SBC to use RTCP-Mux on the respective call leg. When the SBC Core triggers the RTP interception on an RTCP-Mux call (for example, lawful intercept), the SBC forks the RTP and RTCP streams to a single port towards the mediation server. If the intercept is performed in an RTCP-Mux session, the stream sent towards the mediation server is also multiplexed with RTP and RTCP sent over the same port.
Refer to SDP Support for additional RTCP Mux details. NOTE: This flag is only applicable for SIP Trunk Groups. |
rtcpXr | N/A | Specifies control of RTCP-XR block processing and statistics collection.
|
| N/A | Use this flag to specify RTCP termination behavior for pass-through calls.
|
Note
The SBC calculates the packet loss rate as (number of packets lost/number of packets expected) x 100.
For every incoming call leg:
- The SBC periodically (approximately after every 512 expected packets) calculates the packet loss rate.
- The SBC also periodically (approximately after every 10 seconds) checks if the packet loss rate of the call is above the configured value for the parameter
Packet Loss Threshold. - If the SBC detects that the loss rate has exceeded the threshold, it reports the difference to higher layer of services within the software stack.
Command Examples
To configure RTCP options:
% set profiles media packetServiceProfile PSP-1 rtcpOptions rtcp enable
% set profiles media packetServiceProfile PSP-1 rtcpOptions packetLossAction packetLossTrap
% set profiles media packetServiceProfile PSP-1 rtcpOptions packetLossThreshold 10000
% commit
% show profiles media packetServiceProfile PSP-1
rtcpOptions {
rtcp enable;
packetLossThreshold 10000;
packetLossAction packetLossTrap;
}
To configure PSP to transcoderFreeTransparency on both legs:
% set profiles media packetServiceProfile PSP_INT packetToPacketControl transcode transcoderFreeTransparency % set profiles media packetServiceProfile PSP_EXT packetToPacketControl transcode transcoderFreeTransparency
To configure audioTransparecy feature on both legs:
% set profiles media packetServiceProfile PSP_INT audioTransparency unknownCodecBitRate 124 % set profiles media packetServiceProfile PSP_EXT audioTransparency unknownCodecBitRate 124 % set profiles media packetServiceProfile PSP_INT audioTransparency unknownCodecPacketSize 10 % set profiles media packetServiceProfile PSP_EXT audioTransparency unknownCodecPacketSize 10 % set profiles media packetServiceProfile PSP_INT flags reserveBwForPreferredAudioCommonCodec enable % set profiles media packetServiceProfile PSP_EXT flags reserveBwForPreferredAudioCommonCodec enable
To allow secure RTP plus relaying of SRTP audio and video streams and SCTP packet streams, and then to set the DSCP value in the Differentiated Services Field of the IP header for DTLS/SCTP packets that egress the SBC.
% set profiles media packetServiceProfile DEFAULT dtls dtlsFlags enableDtlsSrtp enable dtlsSrtpRelay enable dtlsSctpRelay enable
% set profiles media packetServiceProfile DEFAULT qosValues dtlsSctpDscp 100
% commit
% exit
> show table profiles media packetServiceProfile DEFAULT dtls
dtlsFlags {
allowDtlsFallback enable;
enableDtlsSrtp enable;
dtlsSrtpRelay enable;
dtlsSctpRelay enable;
}
> show table profiles media packetServiceProfile DEFAULT qosValues
msrpDscp 100;
dtlsSctpDscp 100;
To avoid possible interoperability issue in deployments with Kandy Link WebRTC gateways, the Packet Service profile assigned to the trunk group facing the Kandy network should enable the flags that generate and modify SSRC values. Refer to Generate or Replace SSRC Values for Calls Toward a Kandy Link WebRTC Gateway.
For example, use the following commands to configure the flags, in the DEFAULT Packet Service profile, that enable generating SSRC values and allow modification of SSRC values in call hold/resume scenarios. You must enable the generateAndSignalSSRCAndCname flag first.
% set profiles media packetServiceProfile DEFAULT flags generateAndSignalSSRCAndCname enabled % set profiles media packetServiceProfile DEFAULT flags allowMidCallSSRCModification enabled % commit
To configure the SBC to generate RTCP for T140 media streams if it does not receive RTCP from peer:
% set profiles media packetServiceProfile INGRESS rtcpOptions rtcp enable generateRtcpForT140IfNotReceivedFromOtherLeg enable % commit % set profiles media packetServiceProfile INGRESS flags t140Call enable % commit % set profiles media packetServiceProfile INGRESS qosValues t140Dscp 63 % commit
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