Additional sections:
In this section:
199 Early Dialog Termination Support
The SBC acting as P-CSCF or IBCF in IMS deployment scenario supports 199 response code for early media termination using the support199OptionTag flag configurable from the egress IP Signaling Profile. If enabled, SBC includes Option tag in Supported Header for the 199 Extension.
On the other hand, when SBC receives a progress response for INVITE, SBC checks for the response code received from the core; and if the response is 199, SIPSG consumes the response and does not relay to ingress trunk group.
For example, a User Agent Client (UAC) might receive multiple 18x responses from different destinations creating multiple early sessions, when a downstream entity forks the request. The forking entity, on receipt of final response from one of the forked branch, it can use 199 response code (i.e. if the UAC supports 199) to indicate the termination of that particular early dialog. The forking SIP entity might wait for ‘best response code’ and hence cannot send a final response upstream yet. A 199 early session termination indication will help the UACs to release any resources associated with corresponding early session immediately.
The following MMTel supplementary services use 199 response code:
- Communication Completion Services (CCNR in particular)
- Customized Alerting Tones (CAT)
See Supplementary Services topic for a list of MMTel supplementary services.
The CLI syntax to enable the support199OptionTag is shown below:
% set addressContext <address context name> zone <zone name> sipTrunkGroup <TG name> signaling support199OptionTag <disabled|enabled>
MMTel Transparency Support
Event Transparency
SBC transparently passes the following content types associated with the specified MMTel services:
| Service Name | Method | Event Name | Content Type |
|---|---|---|---|
CDIV | SUBSCRIBE | comm-div-info | application/comm-div-info-filter+xml |
CDIV | NOTIFY | comm-div-info | application/comm-div-info-ntfy+xml |
CCBS | SUBSCRIBE (O-AS subscribes to T-AS if the user is Busy) | Call-Completion | |
CCBS | NOTIFY (O-AS subscribes to T-AS if the user is Busy) | Call-Completion |
application/call-completion |
CCBS | Publish (If the CCBS service fails, O-AS sends Publish with closed as state to T-AS) | Presence | application/pidf+xml |
Message Body Transparency
SBC transparently passes the following content-types associated with the specified MMTel services:
| Service Name | Request/Response | Content-Type |
|---|---|---|
CCBS | 486 Response | Message/externalbody |
AOC | INFO,BYE, and 200 OK for INVITE, 18x Response INVITE, 200 OK for BYE | vnd.etsi.aoc+xml |
CW | INVITE | application/vnd.3gpp.cw+xml (MIME Body) |
MCID | INFO | application.vnd.etsi.mcid+xml |
| CRS | INVITE | application/vnd.3gpp.crs+xml |
| CUG | INVITE | application/vnd.etsi.cug+xml |
| USSD | INVITE, INFO, BYE | application/vnd.3gpp.ussd |
Header Transparency
SBC transparently passes Recv-Info and Info-Package headers to support MMTel Services.
Overview
Content Tools