In this section:
Specifies the list of Flags for both H323 and SIP Trunk Groups
To View and Edit Flags
On SBC main screen, go to Configuration > System Provisioning > Category: Trunk Provisioning > Ip Signaling Profile > Common Ip Attributes > Flags. The Flags window is displayed.
H323 Flags
On the Flags window, choose the Ip Signaling Profile as DEFAULT_H323 to view the flags for H323 Trunk Group.
Common Ip attributes - Flags H323 Main Field
The Edit Flags window is displayed:
Trunk Provisioning - Common Ip Attributes H323 Flags
DEFAULT_H323 Flags Parameter
Parameter | Description |
|---|---|
| This flag is deprecated and unused.
Specifies whether to add P Charging Function Address Header flag or not. The options are:
|
| Enable flag to perform audio codec change (e.g. G.711 fax fallback) using empty Terminal Capability Set (TCS). When disabled, Unable to show "metadata-from": No such page "_space_variables" performs audio codec change using request mode.
|
Clearmode For Data Calls | This parameter is used to enable the clearmode function for data calls. When enabled, the SBC 5000 series enables clearmode. When disabled, the SBC 5000 series provides legacy G.711 behavior. The options are:
|
Disable Constrained Capacities | Set this flag to present a full TCS to its peer during call setup or media modification. When disabled, Unable to show "metadata-from": No such page "_space_variables" presents only the selected codec in the TCS, and follows up with a full TCS after media establishment.
|
Disable Media Lock Down |
This flag is deprecated and unused. If SBC offers both pass-thru and transcode codecs, the The options are:
|
Include G729With G729a When Offer Psp Has G729a | Use this flag to control whether the H.323 Service Group includes G.729 along with G.729A in the network offer when the Unable to show "metadata-from": No such page "_space_variables" offer Packet Service Profile has G.729A.
|
Minimize Relaying Of Media Changes From Other Call Leg All | This flag is deprecated and unused. The advertised Sonus SIP SDP is described as a set of capabilities that the SBC can receive. The SBC by default issues a Modify Offer ( re-INVITE, UPDATE) whenever it detects a change in receive capabilities. In certain scenarios, the Modify Offer can be perceived as redundant. Enabling
|
Send Empty Tcs | Enable flag to send empty TCS to the peer to restart the peer’s forward channel in case there is an address update in the direct media case.
|
Terminal Portability Interworking | Controls Terminal Portability Interworking service between ISUP and SIP. When enabled, Terminal Portability Interworking service is enabled. When disabled, Terminal Portability Interworking service is disabled. The service enables a terminal to be moved from one socket to another or a call to be moved from one terminal to another within one call while the call is active. The options are:
|
Send RTCP Port In SDP | When enabled, SBC 5000 series adds the attribute,a=rtcp:<rtcpPort> to the audio and video m lines in the outgoing SDP (Rtcp port mentioned will be SBC RTP port + 1). When disabled, SBC 5000 series does not add the attribute a=rtcp:<rtcpPort> to the audio and video m line in the outgoing SDP. The options are:
|
Use PSX Routefor Registered Invite | This flag is deprecated and unused. Enable flag to route
|
From Header Anonymisation | This flag is deprecated and unused. Use this flag to anonymize the FROM header of
|
Contact Transparency For Is Focus Media Tag | This flag is deprecated and unused. Enable flag to transparently pass Contact header in outgoing message when "isFocus" parameter is received in Contact header. |
Support SCSCFRestoration Procedures | This flag is deprecated and unused. SBC acting as P-CSCF rejects a request with 504 (Server Time-out) response carrying MIME body of type
|
SIP Flags
On the Flags window, choose the Ip Signaling Profile as DEFAULT_SIP to view the flags for SIP Trunk Group.
Common Ip Attributes - Flags Sip Main Field
The Edit Flags window is displayed:
Trunk Provisioning - Common Ip Attributes SIP Flags
The following fields are displayed:
Call Transfer Flag Parameters
Parameter | Description |
|---|---|
Add Path Service Route | Enable this flag to allow Unable to show "metadata-from": No such page "_space_variables" to add 2 Path headers in REGISTER request towards the Core (SBC acting as P-CSCF or IBCF) (Create Service Path Header must be enabled) OR to add 2 Service-Route headers in 200 OK response for REGISTER towards the P-CSCF (SBC acting as IBCF) (Create Service Route Header must be enabled).When
The options are:
|
Add PCharging Func Addr | Specifies whether to add P Charging Function Address Header flag or not. The options are:
|
Call Holding Interworking | Controls Call Hold Interworking service between ISUP and SIP. When enabled, the Unable to show "metadata-from": No such page "_space_variables" has Call Hold Interworking. When disabled, Call Hold Interworking is disabled. The service converts an ISUP call hold to an SIP call hold, or vice-versa. Call holds are invoked by ISUP or SIP/ H.323 endpoints. When disabled, call hold indications are dropped.The options are:
|
ClearMode for Data Calls | This parameter is used to enable the clearmode function for data calls. When enabled, the Unable to show "metadata-from": No such page "_space_variables" enables clearmode. When disabled, the Unable to show "metadata-from": No such page "_space_variables" provides legacy G.711 behavior.The options are:
|
Create PCharging Vector | Controls whether a P-Charging-Vector header is created in outgoing SIP messages. When this parameter is enabled, the Unable to show "metadata-from": No such page "_space_variables" creates a new PCharging-Vector header in the outgoing message. When disabled, the Unable to show "metadata-from": No such page "_space_variables" does not create a new P-Charging-Vector header. Creating P-Charging-Vector headers is supported in INVITE and REGISTER messages. It is also supported in SUBSCRIBE, OPTIONS, and NOTIFY messages when received from the same direction as the REGISTER message.The options are:
|
Create Path Header | Controls whether the The options are:
|
Create Service Route Header | Controls whether the
When The options are:
|
Customized Session Timer Behavior | Specifies the session timer behavior expected by the remote peer. When enabled, the remote peer expects customer-specific session timer behavior. When disabled, the remote peer expects the standard session timer behavior. The options are:
|
Disable Also Header | Specifies whether to use the Also header. When enabled, the The options are:
|
Disable Host Translation | To enable/disable host name translation is disabled. This applies to all URL style headers that require transparency and defines the processing that The options are:
|
Disable Media Lock Down | If SBC offers both pass-thru and transcode codecs, the The options are:
|
Disable Refer To Uri Parameters | By default, parameters in the SIP URI Refer-To header are passed through to the outgoing INVITE. When enabled, this function is Disabled. When disabled, the URI parameters are copied to the Refer To field in the outgoing INVITE. The options are:
|
Discard Received Reason Header | Specifies whether to use the cause code in the Reason header received from the remote peer. When enabled, the Unable to show "metadata-from": No such page "_space_variables" ignores the cause code in the received Reason header. When disabled, the Unable to show "metadata-from": No such page "_space_variables" uses the cause code in the received Reason header. The options are:
|
Do not Include Ss Attribute In Re Invite | Specifies whether the Unable to show "metadata-from": No such page "_space_variables" sends silence suppression to the remote peer. When enabled, the Unable to show "metadata-from": No such page "_space_variables" does not send silence suppression (no a=silenceSupp is sent) in the SDP to the remote peer. When disabled, and when silence suppression is off, the Unable to show "metadata-from": No such page "_space_variables" sends a=silenceSupp:off in the SDP to the remote peer. Note that a=silenceSupp:on is never sent to the remote peer in the Sonus implementation when silence suppression is on. The options are:
|
Enable Default PUIProcedures | Specifies whether to enable the Default PUI Procedure flag or not. The options are:
|
Enable Dial String Handling | This flag is primarily used to enable/disable transparency of dial string (i.e username) received in request URI of INVITE message. Transparency does not occur, however, if PSX/ERE returns globalized or non-private called address. SBC performs dial string identification based on RFC 4967. The options are:
|
End To End Bye | Controls whether the Unable to show "metadata-from": No such page "_space_variables" will issue an end-to-end BYE on the side initiating the disconnect, depending on the receipt of a BYE from the other leg. When enabled, for SIP-SIP calls the Unable to show "metadata-from": No such page "_space_variables" does not issue the 200 BYE on the side initiating the disconnect until the 200 BYE is received from the other leg. When disabled, for SIP-SIP calls the Unable to show "metadata-from": No such page "_space_variables" issues the 200 BYE on the side initiating the disconnect regardless of whether a 200 BYE is received from the other leg. The options are:
|
End To End Re Invite | |
End To End Update | |
End To End Prack | |
Include Ip Ports in From And To Headers | When enabled, port numbers are included with IP addresses in the From and To headers of SIP messages. When disabled, port numbers are not included with IP addresses. The options are:
|
Include Reason Header | When enabled, the Unable to show "metadata-from": No such page "_space_variables" includes the Reason header in 18x, 4xx, 5xx, Cancel, and Bye messages in the forward direction. It is provisioned on the egress trunk group. The options are:
|
Include Ss Attribute In Initial Invite | Specifies whether the Unable to show "metadata-from": No such page "_space_variables" sends the SS attribute in the initial Invite to the remote peer. When enabled, the a=silenceSupp:off is sent in the Initial Invite SDP to the remote peer when Silence Suppression is OFF. When disabled, a=silenceSupp is not sent in the Initial Invite SDP to the remote peer. Note that a=silenceSupp on is never sent to the remote peer in the Sonus implementation when Silence Suppression is ON. The options are:
|
Include Transport Type In Contact Header | When SBC is configured for PSX/ePSX, this flag is used by the PSX SIPE to control inclusion/exclusion of the Transport Type parameter in the Contact headers of 3XX responses. When enabled, the PSX SIPE includes the Transport Type parameter in the Contact headers of 3XX responses. When disabled, the PSX SIPE does not include the Transport Type parameter.
When SBC is configured for ERE, this flag is used by the SBC to control inclusion/exclusion of the Transport Type parameter in the Contact headers of SIP requests and backward 2xx messages when the selected transport is not UDP. The options are:
|
Insert Peer Address As Top Route Header | When enabled, the Unable to show "metadata-from": No such page "_space_variables" SIPE inserts the IP address of the next hop in the top route header of the egress INVITE. This is required when the Unable to show "metadata-from": No such page "_space_variables" is acting as a IMS BGCF proxy. It is also used to support SIPconnect compliance for direct inward dialing. The options are:
|
Map Cause Location | Specifies whether to enable the Map Cause Location flag or not. The options are:
|
Map Suspend Resume Event In PSvc Info Header | Controls whether the Unable to show "metadata-from": No such page "_space_variables" maps the suspend/resume event in the P-Svc-Info header of SIP messages. When enabled, the Unable to show "metadata-from": No such page "_space_variables" maps the suspend/resume event in the P-Svc-Info header. When disabled, the Unable to show "metadata-from": No such page "_space_variables" does not map the suspend/ resume event in the P-Svc-Info header. The options are:
|
Map Uui In PSig Info Header | Specifies whether the Unable to show "metadata-from": No such page "_space_variables" maps the UUI parameter and includes it in the SIP P-Sig-Info header. When enabled, the Unable to show "metadata-from": No such page "_space_variables" maps and includes the UUI parameter. When disabled, the Unable to show "metadata-from": No such page "_space_variables" does not map or include the UUI parameter. The options are:
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Mime Cause Precede Reason Header Cause | When enabled, the cause value is mapped from the MIME body of the incoming message based on the Q.1912 standard. When disabled, the cause value is mapped from the Reason header based on the RFC3398 standard. The options are:
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Minimize Relaying Of Media Changes From Other Call Leg All | The advertised Sonus SIP SDP is described as a set of capabilities that the SBC can receive. The SBC by default issues a Modify Offer ( re-INVITE, UPDATE) whenever it detects a change in receive capabilities. In certain scenarios, the Modify Offer can be perceived as redundant. Enabling When enabled, the SBC suppresses modify offers that have no changes to the “common codecs” that impact the end-user experience. “Common codecs” are codecs that exist both in the initial offer and answer. Changes to common codecs imply changes to DTMF, packetization time, codec specific FMTP attributes and data-path-mode. Refer to the Examples below. The options are:
|
No Content Disposition | Specifies the Content Disposition header format in SIP messages expected by the remote peer. When enabled, the remote peer expects no Content Disposition header. When disabled, the remote peer expects the standard SIP message format, which includes the Content Disposition header. The options are:
|
No Port Number5060 | This parameter is used by the Unable to show "metadata-from": No such page "_space_variables" to control whether port number 5060 is sent to the remote peer in the Request-URI of PRACK, ACK, and BYE messages. When enabled, the outgoing SIP URI does not include the port number 5060 (sip:user@host). In addition, the Unable to show "metadata-from": No such page "_space_variables" only sends out the Record-Route and Route headers of SIP request and response messages with the port number it receives, such that if the Unable to show "metadata-from": No such page "_space_variables" does not receive a port number in Record- Route headers, the Unable to show "metadata-from": No such page "_space_variables" does not send out a port number in the Record- Route and Route headers. When disabled, the outgoing SIP URI includes the port number 5060 (sip:user@host:5060). In addition, if the Unable to show "metadata-from": No such page "_space_variables" does not receive a port number in the Record-Route headers of SIP request and response messages, the Unable to show "metadata-from": No such page "_space_variables" inserts port number 5060 into the outgoing Record-Route and Route headers. The options are:
|
No Userinfo In Contact Header | Specifies the Contact header format in SIP messages expected by the remote peer. When enabled, the remote peer expects no userinfo component in the Contact header URI. When disabled, the remote peer expects the standard format of the Contact header, which includes the userinfo component. The options are:
|
Only Selected Codec In Session Refresh | When this flag is enabled, the SDP in a session keep-alive re-INVITE message will only include the currently-selected codec for the call. When disabled, the SDP in a session keep-alive re-INVITE message will be identical to that in the last offer. See example below.
Example: --> The SBC sends an INVITE including Codec-A and Codec-B <-- An 18x message is received identifying Codec-B. --> The SBC sends a keep-alive reINVITE depending upon the flag setting:
The o-line of the SDP will be identical to that in the last offer. |
P Called Party IDSupport | Specifies whether to enable the P Called Party ID Support flag or not. The options are:
|
P Chg Msg Info | When enabled, the Unable to show "metadata-from": No such page "_space_variables" adds a P-ChgMsg header to a SIP INFO or a 183 Session Progress (which it selects depends on the call state). The P-ChgMsg header contains the interworked ISUP CHG with TLEC information. When disabled, this function is disabled. The options are:
|
Publish IPIn Hold SDP | Enable flag to include the SBC's IP address in the SDP on-hold. The options are:
|
Reject Refer | When enabled, the Unable to show "metadata-from": No such page "_space_variables" rejects SIP REFER messages from the peer and responds with a 405 Method Not Allowed message. The options are:
|
Replace Host On Via Header | This flag will replace the IP address of the top most via header on the outgoing request with IP address or hostname present in the top most via header received. When enabled, this flag replaces the IP address of via header on the initial outbound INVITE or REGISTER with the address received in the via header of the incoming request. When disabled, the Unable to show "metadata-from": No such page "_space_variables" defaults to B2BUA behavior where the VIA header contains the local SIP signaling address. The options are:
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Send RTCPBandwidth Info | Enable flag to send the RR and RS bandwidth information, as well as "b=RR:" and "b=RS:" in the SDP offer.
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Re Query Psx On Register Refresh | When enabled, the Unable to show "metadata-from": No such page "_space_variables" will re- query the Unable to show "metadata-from": No such page "_space_variables" when it receives a register refresh message, which may result in a new or updated result for the register relay. When disabled, the Unable to show "metadata-from": No such page "_space_variables" does not re-query the Unable to show "metadata-from": No such page "_space_variables" on a register refresh. This setting must be made on the ingress trunk group profile facing the registered endpoint.The options are:
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Validate Access Nw Info Header | Specifies whether to forward the P- Access-Network-Info header when the network-provided parameter is present. The options are:
|
Restrict History Info Header | Restricts the History InfoHeader Flag, depending on the Privacy header or Privacy URI header parameter values. The options are:
|
Route Using Recvd Fqdn | Enable flag to use the FQDN received in contact header of Refer-To/3xx for routing.
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Sdp Oline Only Compares | When enabled, the Unable to show "metadata-from": No such page "_space_variables" checks only the o- line when comparing SDPs. When disabled, the Unable to show "metadata-from": No such page "_space_variables" checks the entire SDP body when comparing SDPs. The options are:
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Send All Allowed Codecs For Late Media Invite Or Re Invite | When enabled, the Unable to show "metadata-from": No such page "_space_variables" sends all allowed codecs in the Offer SDP to a late media Invite or Re-Invite. When disabled, the Unable to show "metadata-from": No such page "_space_variables" sends the codec selected in the Offer SDP to a late media Invite or Re-Invite. The options are:
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Send Direct Media Info In Sdp Attribute | Used by the Unable to show "metadata-from": No such page "_space_variables" to enable encoding direct media information in signaling. When enabled, the Unable to show "metadata-from": No such page "_space_variables" sends direct media information in the SDP attribute X-dmi. When disabled, the Unable to show "metadata-from": No such page "_space_variables" does not send direct media information. The options are:
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Send Ptime In Sdp | This parameter takes effect only when the parameter, Unable to show "metadata-from": No such page "_space_variables" sends a=ptime in the SDP. When disabled, the Unable to show "metadata-from": No such page "_space_variables" does not send a=ptime in the SDP. The options are:
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Session Timer Refresh Update | This flag controls the session timer refresh method with SIP peers. When enabled, the Unable to show "metadata-from": No such page "_space_variables" sends UPDATE messages. When disabled, the Unable to show "metadata-from": No such page "_space_variables" resends INVITE messages. The options are:
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Set Accept Header To Application Sdp Only | Specifies the Accept header format in SIP messages expected by the remote peer. When enabled, the remote peer expects a short Accept header format that contains the application/ SDP value only. When disabled, the remote peer expects the standard Accept header format containing all of the standard parameters. The options are:
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Set Oline Dash | Specifies the SDP O-Line format in the SDP of SIP messages expected by the remote peer. When enabled, the remote peer expects an O-Line format in which the username component is set to a "-" (dash). When disabled, the remote peer expects the standard O-Line format containing all of the O-Line parameters, including the username. The options are:
|
Set Session Version Zero | Controls the session version in the outbound SDP. When enabled, the Unable to show "metadata-from": No such page "_space_variables" sets the session version to zero in the o-line of the outbound SDP. When disabled, the Unable to show "metadata-from": No such page "_space_variables" assigns a session version randomly. The options are:
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Set Sline Dash | Specifies the SDP S-Line format in the SDP of SIP messages expected by the remote peer. When enabled, the remote peer expects a short S- Line format that contains a dash only (s=-). When disabled, the remote peer expects the standard S-Line format containing all of the S-Line parameters. The options are:
|
Skip Psx Query For Refer | Skips the PSX query for Refer flag. The options are:
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Store Path Header | Controls whether a Path header received in an incoming SIP message should be stored/cached locally on the Unable to show "metadata-from": No such page "_space_variables" . When enabled, the received Path header is stored. When disabled, the received Path header is not stored. The options are:
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Store Service Route Header | Controls whether a Service-Route header received in a 200-class response to a REGISTER request should be stored/ cached locally on the Unable to show "metadata-from": No such page "_space_variables" . When enabled, the received Service-Route header is stored. When disabled, the received Service-Route header is not stored. The options are:
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Terminal Portability Interworking | Controls Terminal Portability Interworking service between ISUP and SIP. When enabled, Terminal Portability Interworking service is enabled. When disabled, Terminal Portability Interworking service is disabled. The service enables a terminal to be moved from one socket to another or a call to be moved from one terminal to another within one call while the call is active. The options are:
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Send Rtcp Port In Sdp | When enabled, Unable to show "metadata-from": No such page "_space_variables" adds the attribute,a=rtcp:<rtcpPort> to the audio and video m lines in the outgoing SDP (Rtcp port mentioned will be SBC RTP port + 1). When disabled, Unable to show "metadata-from": No such page "_space_variables" does not add the attribute a=rtcp:<rtcpPort> to the audio and video m line in the outgoing SDP. The options are:
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Store PCharging Func Addr | Specifies whether to store the P Charging Functional Address or not. The options are:
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Store PCharging Vector | When this flag is enabled, the SBC stores the P-Charging-Vector (PCV) received in requests. When the response is forwarded back, the stored PCV is inserted and sent. If the SBC receives the PCV when this flag is disabled, the SBC ignores the PCV and does not log the CDR. The options are:
Example of SBC acting as IBCF: |
Create PVisited Network Id | Specifies whether to create the P visited network ID or not. The options are:
|
Lock Down Preferred Codec | Enable this flag to maintain the most preferred codec of the leg on which it is enabled even if it requires transcoding. This feature also suppresses the re-INVITE triggered on the leg (on which it is enabled from the SBC) due to a MODIFY offer received from the other leg as part of mid-call codec modification.
This flag must be enabled in conjunction with When this flag is enabled, the flag “ |
Send Only Preferred Codec | Use this flag to send a single preferred codec in an Answer for an Initial Offer or Re-Invite.
|
Suppress Min Se If Not Received | When The options are:
|
Use PSX Routefor Registered Invite | Enable flag to route
|
From Header Anonymisation | Enable this flag to prevent the FROM header of
|
No Service Route Hdr For Emergency Registration | Enable this flag to deny SBC from adding Service-Route headers for emergency registrations even if
|
Insert PAccess Network Info | Enable flag to construct and send PANI with received location info.
|
Contact Transparency For Is Focus Media Tag | Enable flag to transparently pass Contact header in outgoing message when "isFocus" parameter is received in Contact header. |
Support SCSCFRestoration Procedures | SBC acting as P-CSCF rejects a request with 504 (Server Time-out) response carrying MIME body of type
|
Insert UEFlow Info | Enable flag to send P-UE-Flow-Info header towards core.
|
Accept Alert Info | Enable flag for SBC to process the URI specified in the Alert-info header received in the 180 ringing message and use the tone specified in the Alert-Info header as the Local Ring Back Tone to play. When this flag is enabled, the tones processed override any incoming tones in the media stream. For example, when Accept Alert-Info is enabled, the SBC plays the tone specified in the Alert-info header of 180 ringing message overriding the inband tones included in the 180 ringing message.
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Make the required changes and click Save at the right hand bottom of the panel to save the changes made.
Call Flow Examples
Call Flow Examples for 'Disable Media Lockdown' Flag
Example1:
In the following call flow, the Modify Offers (in green) are suppressed if the Minimize Relaying Of Media Changes From Other Call Leg flag is enabled:
Ingress Peer |
| SBC |
| Egress Peer |
G711U | -> | SBC offers G711U as pass-through codec and G729A as a transcode option by reserving a DSP channel | -> | G711U,G729A |
G711U | <- | SBC releases the DSP channel resulting in a G711U pass-thru call | <- | G711U |
|
| Receive capabilities of SBC have changed as a codec G729A was removed and the DSP channel de-allocated. | -> | G711U |
|
|
| <- | G711U |
Example 2:
The messages (in green) can be suppressed if the Disable Media Lock Down field is enabled.
Ingress Peer |
| SBC |
| Egress Peer |
G711U | -> | SBC offers G711U as pass-through codec and G729A as a transcode option by reserving a DSP channel | -> | G711U,G729A |
G711U | <- | SBC releases the DSP channel resulting in a G711U pass-thru call | <- | G711U,G729A |
|
| Receive capabilities of SBC have changed as a codec G729A was removed and the DSP channel de-allocated. | -> | G711U |
|
|
| <- | G711U |
Ingress Peer |
| SBC |
| Egress Peer |
G711U | -> | SBC offers G711U as pass-through codec and G729A,G726 as transcode options by reserving a DSP channel | -> | G711U,G729A,G726 |
G711U | <- | Transcode G711-G729A call. Egress codec is locked down to G729A | <- | G729A,G726 |
|
| Receive capabilities of SBC have changed to G729A due to transcode. | -> | G729A |
|
|
| <- | G729A |
Example 3:
Scenario in which Disable Media Lockdown field can not suppress the media lock down messages (in green).
The codecs configured at Egress route PSP are G711U, G726, G729A with HRP disabled.
Ingress Peer |
| SBC |
| Egress Peer |
G711U | -> | SBC offers G711U as pass-through codec and G726,G729A as transcode options by reserving a DSP channel | -> | G711U,G726,G729A |
G711U | <- | Transcode G711-G726 call. Egress codec is locked down to G726 | <- | G729A,G726 |
|
| Receive capabilities of SBC have changed to G726 ( i.e. HRP is disabled). Since, the codec selected by SBC is different from Peer’s preferred codec (G729), though the flag DML is enabled SBC sends a Modify Offer to lockdown to G726. | -> | G726 |
|
|
| <- | G726 |
Call Flow Examples for 'Minimize relaying of Media Changes From Other Call Leg All' Flag
Example1:
The re-INVITEs (in green) are suppressed if the Minimize Relaying Of Media Changes From Other Call Leg flag is enabled.
Ingress Peer |
| SBC |
| Egress Peer |
G711U | -> | SBC offers G711U as pass-through codec and G729A as a transcode option by reserving a DSP channel | -> | G711U,G729A |
G711U | <- | SBC releases the DSP channel resulting in a G711U pass-thru call | <- | G711U |
|
| Receive capabilities of SBC have changed as a codec G729A was removed; send Modify Offer to Peer to advertise the latest set of capabilities | -> | G711U |
|
|
| <- | G711U |
Example2:
SBC suppresses a Modify Offer from the ingress peer. The offer changes the maxptime from 10 to 20ms. An increase in maxptime can be suppressed – a device that advertises a maxptime of 20ms can also receive 10ms packets.
Ingress Peer |
| SBC |
| Egress Peer |
G711U 10ms | -> |
| -> | G711U 10ms |
G711U | <- |
| <- | G711U |
Re-INVITE (G711U 20ms) | -> | Suppress the re-INVITE if minimize media is enabled and respond to ingress peer; else forward the re-INVITE to egress | -> | G711U 20ms |
G711U | <- |
| <- | G711U |
Conversely, irrespective of the state of the Minimize Relaying Of Media Changes From Other Call Leg flag All field cannot suppress a change of maxptime from 20ms to 10ms.
Ingress Peer |
| SBC |
| Egress Peer |
G711U 20ms | -> |
| -> | G711U 20ms |
G711U | <- |
| <- | G711U |
Re-INVITE (G711U 10ms) | -> |
| -> | G711U,10ms |
G711U | <- |
| <- | G711U |
Example3:
A change of data-path-mode from sendrecv to sendonly ( HOLD request) can also be suppressable. The rational is that SBC can always ignore the media received from the peer and continue to send it media.
Ingress Peer |
| SBC |
| Egress Peer |
G711U sendrecv | -> |
| <- | G711U sendrecv |
G711U | <- |
| -> | G711U |
Re-INVITE (G711U sendonly) | -> | Suppress the re-INVITE if minimize media is enabled and respond to ingress peer; else forward the re-INVITE to egress | <- | G711U sendonly |
G711U | <- |
| -> | G711U |
Conversely, SBC irrespective of the state of the Minimize Relaying Of Media Changes From Other Call Leg flag, cannot suppress a change of data-path-mode from sendonly to sendrecv.
Ingress Peer |
| SBC |
| Egress Peer |
G711U sendonly | -> |
| -> | G711U sendonly |
G711U | <- |
| <- | G711U |
Re-INVITE (G711U sendrecv) | -> |
| -> | G711U sendrecv |
G711U | <- |
| <- | G711U |
Call Flow Examples for 'Relay Data Path Mode Change From Other Call Leg' Flag
Example1:
When Minimize Relaying Of Media Changes From Other Call Leg flag is enabled, and when Relay Data Path Mode Change From Other Call Leg is disabled:
Ingress Peer |
| SBC |
| Egress Peer |
G711U,G729A sendrecv | -> |
| -> | G711U,G729A sendrecv |
G711U | <- |
| <- | G711U |
Re-INVITE (G711U sendonly) | -> | Suppress the re-INVITE and respond to ingress peer. Discard media received from the egress peer |
|
|
G711U | <- |
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Example2:
When the Minimize Relaying Of Media Changes From Other Call Leg flag is enabled, and when Relay Data Path Mode Change From Other Call Leg is enabled:
Ingress Peer |
| SBC |
| Egress Peer |
G711U,G729A sendrecv | -> |
| -> | G711U,G729A sendrecv |
G711U | <- |
| <- | G711U |
Re-INVITE (G711U sendonly) | -> |
| -> | G711U sendonly |
G711U | <- |
| <- | G711U |
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