IMG 1010 - Interworking from SIP to ISUP
- Kelli Higdon
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The SIP to ISUP Interworking object gives the user the ability to manipulate the interworking of the ACM (Address Complete Message) and the CPG (Call Progress Message). The SIP_SS7 Interworking object supports manipulating the ACM and CPG messages for both RFC 3398 and Q.1912.5 (03/2004). Using the SIP_SS7 Interworking object a user can also force the ACM and CPG messages to be interworked into 180 Ringing unconditional or 183 Session Progress unconditional as well. Refer to call flow diagrams for high level interworking scenarios.
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IMG EMS > Profiles > SIP (SGP) Profile > New SIP_SS7 Interworking
Maximum Objects:
1 SIP_SS7 Interworking object Pane per SIP SGP object pane
Related Topics:
IMG 1010 - Configuring SS7 Signaling - 10.5.1
ClientView Pane: Software 10.5.3 SP5+
ClientView Pane: Software 10.5.0 - 10.5.3 SP4.3
ClientView Pane (before 10.5.0):
Field Descriptions:
The field options vary depending on which selection is made. Tables below display the cardinality when selecting each option within the individual fields. The mappings below are based on RFC 3398 and Q.1912.5 (03/2004).
ACM Mapping Procedure/ACM Mapping Condition
An ACM message is sent in certain situations to indicate that the call is in progress in order to satisfy ISUP timers, rather than to signify that the callee is being alerted.
The Address Complete Message (ACM) mapping is dependent on both the ACM Mapping Procedure field and the ACM Mapping Condition field. Below is table displaying the ACM Mapping Procedure, ACM Mapping Condition and the 183 Session Progress or 180 Ringing message transmitted from IMG. Click in the ACM Mapping procedure field and select option from drop down menu. Once the ACM Mapping Procedure has been configured, Click in the ACM Mapping condition field and a Select Multiple Items box appears. To select multiple choices, hold the <CTRL> key down and click on each choice. Below are the selections:
ACM Mapping Procedure | ACM Mapping Condition | 18x message sent to SIP |
Default (RFC 3398) | Default | 183 Session Progress |
don't care BCI/CPS no indication "00" | 183 Session Progress | |
don't care BCI/interworking encountered "01" | 183 Session Progress | |
don't care OBCI (in-band info) "01" | 183 Session Progress | |
don't care cause code | 183 Session Progress | |
ACM to 180 Ringing unconditional | Not Applicable | 180 Ringing |
ACM to 183 Progress unconditional | Not Applicable | 183 Session Progress |
Q.1912.5 ACM procedure | CPS = subscriber free + cause is not interworked | 180 Ringing |
CPS = subscriber free + cause is mapping 180 | 183 Session Progress |
If multiple items are selected and the Called Party Status (CPS) parameter comes in with an "01" subscriber free the message sent out on the SIP side will be the 180 Ringing message.
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When Default (RFC 3398) is chosen the mapping of ISUP messaging will follow the rules set up using RFC 3398.
CPG Mapping Procedure
The Call Progress message (CPG) is sent in either direction during the set-up or active phase of the call, indicating that an event, which is of significance, and should be relayed to the originating or terminating access, has occurred.
The Call Progress message (CPG) mapping is dependent on both the CPG Mapping Procedure field and the CPG Mapping Condition field. Below is table displaying the CPG Mapping Procedure, CPG Mapping Condition and the 183 Session Progress or 180 Ringing message transmitted from IMG. Click in the CPG Mapping Procedure field and select option from drop down menu. Once the CPG Mapping Procedure has been configured, Click in the CPG Mapping condition field and a Select Multiple Items box appears. To select multiple choices, hold the <CTRL> key down and click on each choice. Below are the selections:
CPG Mapping Procedure | CPG Mapping Condition | 18x message sent to SIP | |
Default (RFC 3398) | Default | CPG (event indicator = alerting) | 180 Ringing |
CPG (event indicator = progress) | 183 Session Progress | ||
CPG (event indicator = in band info) | 183 Session Progress | ||
CPG (event indicator = progress) | Not Interworked to SIP | ||
CPG (event indicator = in band info) | Not Interworked to SIP | ||
CPG to 180 Ringing unconditional | Not Applicable | 180 Ringing | |
CPG to 183 Progress unconditional | Not Applicable | 183 Session Progress | |
Q.1912.5 CPG procedure | Default | CPG (event indicator = alerting) | 180 Ringing |
CPG (event indicator = progress) | Not Interworked to SIP | ||
CPG (event indicator = in band info) | Not Interworked to SIP | ||
CPG (progress) | Map to 183 | ||
CPG (in band info) | Map to 183 | ||
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If multiple items are selected and the Called Party Status (CPS) parameter received is an "01" subscriber free, the message sent out on the SIP side will be the 180 Ringing message.
Max Forward Value
The Max-Forwards value is an integer in the range 0-255 indicating the remaining number of times this request message is allowed to be forwarded. This count is decremented by each server that forwards the request. The default value is 70. Select from drop down menu 0-255.
Max Forward Hop Counter Interworking
By enabling the Hop Counter / Max Forward Interworking field, the IMG will now map the Hop Counter parameter in the IAM message to the Max Forward Header field in the SIP INVITE. Refer to IMG 1010 - Hop Counter / Max Forward Interworking topic for more information on how this feature functions.
Disable (Default)- The Max Forwards header parameter in the SIP Invite WILL NOT be mapped to the Hop Counter parameter in the SS7 IAM message. Also, the Hop Counter parameter in the SS7 IAM message WILL NOT be mapped to the Max Forwards header parameter in the SIP Invite.
Enable- The Max Forwards header parameter in the SIP Invite WILL be mapped to the Hop Counter parameter in the SS7 IAM message. Also, the Hop Counter parameter in the SS7 IAM message WILL be mapped to the Max Forwards header parameter in the SIP Invite.
REL Diagnostic field to Reason-Extension
When a call is released on the SS7 side, information is then sent to the SIP side regarding why the call was released. The Diagnostic field information embedded in the SS7 REL message can be configured to be interworked into the reason-extension parameter of the SIP Reason Header's Field in the SIP BYE, CANCEL, 4xx, 5xx, 6xx messages. The selections below either enable or disable this functionality. Refer to the IMG 1010 - SS7 Diagnostic byte to Reason Header IW topic for more information on this feature.
Disable (Default)- When an SS7 Release message is received which contains the Diagnostic Field value x offered, it will NOT be interworked to the SIP side.
Enable- When an SS7 Release message is received which contains the Diagnostic Field value x offered it will be interworked into the Reason Header's reason-extension parameter that is sent in the BYE, CANCEL, 4xx, 5xx, and 6xx Reason Header field.
Location Number IW
Enable- SIP P-Access-Network-Info and the SS7 location number parameter of the IAM message are interworked (per 3GPP TS 29.163 specification).
Disable- SIP P-Access-Network-Info and SS7 location number are not interworked.
For SS7 to SIP call interworking, the outgoing SIP call only supports the P-Access-Network-Info with access-type="GSTN" and gstn-location parameter format.
For incoming SIP call, the P-Access-Network-Info header with access-info="operator-specific-GI" and operator-specific-GI parameter format is also supported.
The Location Number IW parameter can also be supported for cases where the ISUP content is contained within a MIME attachment as per SIP-T or SIP-I.
Nature Of Address
The value for nature of address.
Possible values: 0 to 127*
Numbering Plan Indicator
The value for numbering plan indicator.
Possible values: 0 to 7*
Screening Indicator
The value for screening indicator.
Possible values: 0 to 3*
*The values only apply to SS7 location number when SIP P-Access-Network-Info header with access-info="operator-specific-GI" and operator-specific-GI parameter are present.
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