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As described in Feature F-5230, the H.223 and H.245 protocols are used between multimedia endpoints over a circuit switched network. These protocols are utilized after a successful call between two endpoints that indicates the call is for multimedia. Feature F-5698 gives the IMG the ability to detect an incoming SS7/ISDN multimedia call based on a specific octet contained in the SS7/ISDN setup message. If the call is considered an audio call, the message will be interworked as a normal ISDN/SS7 to SIP call. If however, the call is considered a multimedia call, a proprietary SIP Header can be added indicating it is a multimedia call and the added header will be interworked to the SIP side. The feature is enabled through a new header added to the SIP Headers object. Refer to the information below.
Call Flow Diagram
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As displayed in Call Flow diagrams above, the following is true:
Both the audio call and the multimedia call are routed to the same endpoint.
A special SIP proprietary header is added to the INVITE message indicating the incoming SS7/ISDN setup message is for multimedia (H.223 and H.245 is set in the User Information Layer 1 Protocol codepoint).
The INVITE for the audio call has no special header, -or- it can contain a header indicating the call is not for multimedia.
Call Trace
CALL> 14:23:59.936 CALL(SS7) (00:00001:00)
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14:24:00.076 CALL(SS7) (00:00001:00) SENT ANM to (0x809:0x1012:500)
Configuration
Before being able to configure the IMG to interwork the SIP Proprietary header between SS7 or ISDN and SIP, the following objects must first be configured. Configure these initial objects before proceeding to the procedure below.
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The procedure below describes how to configure the IMG . In the procedure below the incoming side is ISDN and the outgoing side will be SIP since the feature supports a call going from ISDN to SIP. If call flow is SS7 to SIP, the procedure would be modified for SS7 signaling, but the basic configuration will all be the same.
Create ISDN Signaling and ISDN Channel Group (Incoming Channel Group)
Right click on the IMG Name object (Physical Node) and select New Signaling. The Signaling object is a container object for all signaling on the IMG. No more configuration is needed within this object. Refer to IMG 1010 - Signaling Object topic for more information on this object
Right click on the Signaling object and select New ISDN. A ISDN D-Channels object will get created. This is a container object and no configuration is needed here. Refer to the IMG 1010 - ISDN Signaling Pane topic for more information on this object.
Right click on the ISDN D-Channels object and select New ISDN D-Channel. Configure the D-Channel in this object. Refer to the IMG 1010 - ISDN D Channel topic for more information on configuring this object.
Right click on IMG EMS and select New Routing Configuration. A Routing Configuration Pane will appear. Refer to the IMG 1010 - Routing Configuration Object topic for more information on this object.
Right click on Routing Configuration and select New Channel Groups. A Channel groups container object is created. This object will allow multiple channel groups to be created beneath it. Refer to the IMG 1010 - Channel Groups topic for more information on this object.
Right click on the Channel Groups Object and select New Channel Group. A Channel Group Object will appear. Enter a name for this channel group and set the Signaling Type to ISDN. In this example, the channel group was labeled ChGrp_ISDN. Refer to the IMG 1010 - Channel Group topic for more information on configuring this object.
Right click on the ISDN Channel group just created and select New ISDN Group. Select a D-Channel from drop down menu in the ISDN D channel field. Refer to the IMG 1010 - ISDN Group topic for more information on configuring this object.
Right click on the ISDN Group object just created and select New ISDN Circuits. Select which spans/channel will be utilized in this ISDN circuits group. Refer to the IMG 1010 - ISDN Circuits topic for more information on configuring this object.
Create SIP SGP and SIP Headers objects
Configure SIP Header object to enable X-DialogicMultimedia:yes/no data field. Once configured, and depending on the selections made, the IMG will add a SIP Proprietary Header to the outgoing SIP network.
Right Click on the Profiles object and select New SIP SGP. Once SIP SGP pane is created, change the SIP Profile ID field to something other than 0 by selecting a different ID from the drop down menu. This will allow user to edit the SIP SGP Profile. Refer to topic for more information on configuring this object.
Right Click on the SIP SGP Profile object and select New SIP Headers. In the SIP Headers object that appears select one of the choices in the drop down menu of the field X-Dialogic Multimedia Call. In this procedure, Multimedia call and Audio call was selected from drop down menu. See screen capture below. Refer to topic for more information.
Create SIP Signaling Stack
Configure the SIP signaling stack on the IMG.
Right click on the Signaling object and select New SIP. Refer to the IMG 1010 - SIP Signaling Object topic for more information on configuring this object.
Create SIP Channel Group
Right click on Channel Groups object created earlier and select New Channel Group. Set the Signaling Type field to SIP and enter a name for this channel group. Refer to IMG 1010 - Channel Group topic for more information on configuring a SIP Channel Group.
Create External SIP Gateway
The gateway being created is the SIP endpoint on the SIP network that the IMG will be communicating with. Follow procedure below.
Right click on IMG EMS and select New External Network Elements. No configuration is accomplished here. The External Network Element pane is a container object to multiple external entities in the network. Refer to IMG 1010 - External Network Elements topic for more information.
Right click on the External Network Elements object and select New External Gateways. Again, no configuration is accomplished here. Refer to IMG 1010 - External Gateways object for more information.
Right click on External Gateways object and select New External Gateway. Enter a name to identify this gateway, modify the Gateway Signaling Protocol field to display SIP, and enter an IP address in the Gateway IP Address field.
Within the SIP Profile field of the External Gateway object, select the SIP SGP created above for the X-DLGCMultimedia: Data feature. See screen capture below. Refer to the IMG 1010 - External Gateway topic for more information.
Point SIP Channel group to gateway created
The SIP Channel group created above must point to the external gateway just created.
Right Click on the SIP Channel group created above and select New IP Network Element. In the IP Network Element field, select from drop down menu the gateway created above. Refer to the IMG 1010 - IP Network Element topic for more information on this object. See screen capture below
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Route SIP Channel group to ISDN Channel group
At this point the feature has been configured and both the ISDN and SIP channel groups have been configured. Using routing information, configure the routing so the ISDN channel group and SIP channel group created route to each other.
Additional Information
This feature is supported from SS7 to SIP -or- ISDN to SIP.
The feature in NOT supported in SIP to SS7 nor is it supported from SIP to ISDN. If the IMG receives the proprietary SIP header, it will not be recognized and not interworked.
For ISDN, the User Information Layer 1 Protocol codepoint can be found in the Low Layer Compatibility IE and/or in the Bearer Capability IE. Both IE's are present in the SETUP message.
For SS7, the Low Layer Compatibility IE can be found in the Access Transport parameter. The Bearer Capability IE is equivalent to the User Service Information parameter. Thus, the User Information Layer 1 Protocol codepoint can be found in the Low Layer Compatibility IE in the Access Transport parameter, and it can be found in the User Service Information parameter. These two parameters are present in the SS7 IAM message.
The feature is disabled by default and can be configured under the SIP Headers object in ClientView. The field is labeled X-Dialogic Multimedia Call.