Message Waiting Indicator
The IMG 2020 can accept an incoming SIP NOTIFY request (outside of a subscription) which has the parameters Event type = message summary and Content Type = application/simple-message-summary and interwork these messages into an SS7 network using TCAP messaging. SIP uses the SIP Specific Event Notification (Notify) as a mechanism to transport the MWI message through IP and the IMG 2020 then inter-works the Notify message along with its Event Package Name simple-message-summary to the SS7/outgoing side. The IMG 2020 then receives a response from the SS7 network and inter-works this response to the SIP network and sends the response out in the 200 OK message. This feature supports RFC 3842 section 5.2 only. The MWI feature is supported in both ANSI and ITU protocol.
Diagram
Call Flows
Call Trace
Configuration
Initial Configuration
Before configuring, the IMG 2020 must have an initial configuration created on it. Follow the Basic Configurations procedure before proceeding onto configuring the MWI feature.
Configure SIP Profile
Configure a SIP Profile that allows a Notify message to be sent without a Subscribe message.
Create a SIP Profile. Right click on the Dialogic object and select New Profiles. The Profiles object is a parent or container object and no configuration is needed here.
Right click on the Profiles object and select New SIP Profile. The first profile that gets created is a Default SIP Profile and cannot be modified. Disregard this profile.
Right click on the Profiles object just created again and select New SIP Profile. Either enter a Name into the name field that identifies this profile or accept the default entry. Refer to the SIP Profile - SGP topic for more information on configuring each of the individual fields.
Right click on the SIP Profile object just created and select New Advanced Settings. Within the field labeled Allow NOTIFY w/o Subscription, select Allow from the drop down menu. Refer to the SIP Profile - Advanced Settings topic for more information on configuring each of the individual fields.
Create SIP Signaling Stack
Right click on the IMG 2020 physical node and select New Signaling. The Signaling object is a parent or container object and no configuration is needed here. Refer to the Signaling topic for more information on this object.
Right click on the Signaling object created and select New SIP. In the IP Address field, select from the drop down menu which IP address will be used for SIP signaling. Refer to IMG 1010 - SIP Signaling Object topic for more information.
Create SIP Channel Groups
Right click on the Dialogic object and select New Routing Configuration. The Routing Configuration object is a parent or container object and no configuration is needed here. Refer to the Routing Configuration topic for more information.
Right click on Routing Configuration and select New Channel Groups. The Channel Groups object is a container object also and no configuration is needed. Refer to the Channel Groups topic for more information.
Right click on Channel Groups object and select New Channel Group. Either enter a name that identifies this channel group or accept the default entry. In this example the Channel Group was labeled SIP_MWI_ChGrp.
Select SIP from the drop down menu of the Signaling Type field. Refer to Channel Group topic for more information on configuring this object.
Create an External Gateway
The SIP Channel group needs to communicate with an external SIP entity. Create an external network element and then an external gateway that the SIP channel group will transmit messages to. Follow procedure below to communicate with a remote gateway.
Right click on the Dialogic object and select New External Network Elements. The External Network Elements object is a parent or container object and no configuration is needed here. Refer to External Network Elements topic for more information.
Right click on External Network Elements and select New External Gateways. The External Gateways object is a parent or container object also and no configuration is needed here. Refer to External Gateways for more information.
Right click on External Gateways and select New External Gateway. Enter a name that identifies the gateway being configured. In this example the gateway was labeled SIP_MWI_GW
Individual Field Descriptions |
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For more information refer to the External Gateway topic.
Insert SIP External Network Element into SIP Channel Group
Right click on the SIP Channel group created and select New IP Network Element. Within the IP Network Element field, select from drop down menu, the gateway created. See screen capture below.
Click on the Channel Groups object again. The Channel Groups object will have a yellow exclamation point in place of the icon indicating the configuration has not been sent to the IMG 2020. Click on the Download Resource Tables button and the new configuration will be sent to the IMG 2020.
At this point, the Incoming SIP side of the configuration is complete. Follow instructions below to configure the outgoing SS7 side.
Configure SS7 Stack
An SS7 stack must be configured.
Configure SS7 Signaling and SS7 Network
When configuring SS7 signaling, an SS7 Network is created. The first two objects are the SS7 Signaling and SS7 Network objects. Follow the instructions below to create these objects.
Right click on the Dialogic object and select New SS7. The SS7 object is a parent or container object and no configuration is needed within this object. Refer to the SS7 - Signaling topic for more information.
Right click on theSS7object and select New SS7 Network. Select a Network ID from the drop down menu. Refer to the topic for more information on this object.
Right click on the SS7 Network object and select New SS7 Nodes. The Nodes object is a parent or container object and no configuration is needed in this object. Refer to the SS7 - Nodes topic for more information on this object.
Right click on the SS7 Nodes object and select New Primary Node. Within the Primary Node object select from the drop down menu which node will be utilizing the SS7 network that is being created. Refer to the SS7 - Nodes - Primary Node topic for more information on this object.
Configure SS7 Stack
Configure the SS7 signaling stack and enter its Originating Point Code. Follow procedure below.
Right click on the SS7 Network object and select New SS7 Stack. An SS7 Stack pane will get created. Enter the information needed for your specific network.
Configuring the IMG 2020 for MWI by enabling SCCP and TCAP signaling in the stack. Select ANSI from drop down menu of the SCCP field.
Select either ANSI or ITU from the drop down menu of the TCAP field. See screen capture below.
Refer to the SS7 - Stack topic for more information on configuring the individual fields of the SS7 Stack Pane.
Configure SS7 Link Set
A signaling link set is an abstract path between the IMG 2020 and an APC (Adjacent Point Code). Within each link set, multiple physical signaling links can be added. A signaling stack must be assigned to all links in a link set. A typical configuration consists of two link sets. When configuring multiple SS7 stacks, the Link Set ID's assigned to each signaling stack must be different. For example, if Link Set ID is assigned to Stack 1, it cannot also be assigned to Stack 2.
Right click on the SS7 Stack and select New SS7 Link Set. The link set ID is automatically populated with the next available ID.
In the APC (Adjacent Point Code) enter the point code to which this link set will be connected. The format of the APC needs to follow the format given to the OPC. For example if the OPC is ITU 97, which follows the format 3-8-3, the APC should also be running ITU 97 and follow the 3-8-3 format. For more information on configuring the Link Set object refer to SS7 - Link Set topic.
Configure SS7 Link
An SS7 Signaling Link is a point-to-point connection between two SS7 point codes (For example: A IMG 2020 and an STP). The Signaling Link is configured under the Signaling Link Set. The place holder assigns a physical location in the IMG 2020 (timeslot) and a previously configured Signaling Link Set to a Signaling Link. When configuring multiple stacks, the Link ID's assigned to each signaling stack must be different. For example, if Link ID:1 is assigned to Stack 1, it cannot also be assigned to Stack 2.
Right click the desired SS7 Link Set and select New SS7 Link. The Link ID field is automatically populated with the next available ID.
In the BDN Node field will be all the nodes created within the SS7 Nodes object. Select from drop down menu which node the link being created is associated with.
In the Span and Channel fields, select the DS-1/DS-0 that the link will be created on. The Span and Channel fields have a drop-down menu which includes all the DS-1's/DS-0's available on the specific node selected. By default the first available DS-1/DS-0 is displayed. For more information on the individual fields in the SS7 Link pane refer to SS7 - Link Set - Link topic.
Configure the Destination
The SS7 Destination object communicates to the stack the Destination Point Code of the SS7 endpoint. The SS7 Destination is termed as the endpoint in an SS7 network and is not considered any of the signaling transfer points the SS7 signaling passes through to get to the endpoint. Follow procedure below.
Right click on the SS7 Stack again and select New Destination. The Destination ID is automatically populated and cannot be modified.
Enter the point code of the endpoint in the DPC field.
ITU - Point codes range from 0-0-0 to 7-255-7.
ANSI - Point codes range from 0-0-0 to 255-255-255.
Configure SS7 Routes
The path the SS7 signaling messages pass going from the OPC (Originating Point Code) to the DPC (Destination Point Code) is the SS7 Route. When configuring multiple SS7 stacks, the Route ID's assigned to each signaling stack must be different. For example, if Route ID:1 is assigned to Stack 1, it cannot also be assigned to Stack 2.
Right click on the Destination object and select New SS7 Route. The SS7 Route pane appears. The Route ID field is automatically populated with the next available ID.
Select the Linkset that will be used from the drop down menu of the Linkset field.
Use the Comments field to enter a meaningful name to identify the route. For more information on the SS7 Route pane refer to the SS7 - Destination - Route topic.
Configure SCCP/TCAP Functionality
Right click on the SS7 Stack object created above and select New SCCP/TCAP. The SCCP/TCAP pane is a parent or container object and no configuration is needed here. This pane will allow you to configure other objects that have to do with SCCP/TCAP. Refer to SCCP - TCAP topic for more information on this pane.
Right click on the SCCP/TCAP object and select New Subsystem Number. Select a Subsystem Number from the drop down menu. The Subsystem Number Status is by default set to Prohibited. Using the buttons just below the Subsystem Pane, click on the Allow button and the status will change to Allowed. Refer to the Subsystem Number topic for more information on configuration of the Subsystem Number Pane.
Right Click on Subsystem Number and select New Adjacent Translator. Select from drop down menu the Adjacent Point Code that will be used for the Message Waiting Indicator. The point codes in drop down menu are point codes from the DPC of the Route ID. Refer to the Adjacent Translator topic for more information.
Configure GCL Services for SIP to TCAP Interworking
Right click on the SS7 Network object again and select New GCL Services. The GCL Services object is a parent or container object and no configuration is needed here. Refer to the GCL Services topic for more information on this object.
Right click on GCL Services object and select New MWI SIP-TCAP Interworking. In the Subsystem field, select from the drop down menu the stack that was created earlier. In the ANSI MWI Protocol field, select from the drop down menu the protocol to format the MWI message. Refer to the screen capture below. For more information on the SIP-TCAP MWI (Interworking) object, refer to the MWI - (SIP/TCAP Interworking) topic.
Once the GCL Service has been created, the new service can be added to the SIP Channel Group created above. Right click on the SIP Channel Group created above and select New Channel Group Service. Refer to the topic for more information on this object.
Select from drop down menu the service that will be associated with this channel group. See screen capture below.
Configure the SS7 ISUP Group and Circuit Group (CICs)
Under the Destination object, multiple ISUP Groups can be created. The ISUP Groups created will be linked to the Channel Group object which will be completed in the next section. Follow procedure below which creates an ISUP Group.
Right click the Destination object again and select New SS7 Group. Select from the drop down menu of the ISUP Profile field which ISUP Profile will be used in the ISUP Group being created. Refer to the ISUP Group topic for more information on configuring each of the separate fields within this object.
OPTIONAL: Right click on the SS7 ISUP Group created and a list of advanced ISUP Group parameters will appear. Select one or more parameters to be added to the ISUP Group being created. Refer to the Configure ISUP Group Advanced Parameters topic for information on each of the individual parameters.
Right click on the SS7 Group object again and select New SS7 Circuit Group. In the Node Name field, select the Node from which the DS-1's and DS-0's will be used to create the CICs. The nodes in the list will be from the list of nodes under the SS7 Nodes object created earlier.
Select from the drop down menu of the next four fields, the Starting and Ending Spans/Channels (DS-1's/DS-0's). The DS-1/DS-0's in the drop down lists will be all the available DS1's/DS0's available on the node selected above.
Enter a Starting CIC number into the Start CIC field. Refer to the SS7 - Circuit Group under Signaling topic for more information on this object.
Configure SS7 Channel Groups and a Second SS7 Circuit Group
Configure an SS7 Channel Group to communicate with the local SS7 network.
Right click on the Channel Groups object and select New Channel Group. In the Name field, either accept the default name entered or enter a name that will identify this specific Channel Group.
Select SS7_ISUP from the drop down menu in the Signaling Type field. For more information on configuring the SS7 Channel Group refer to Channel Group topic.
Right Click on the SS7 Channel Group created and select New Circuit Group. As described in the Configure the SS7 ISUP Group and Circuit Group (CICs) section above, select the node and DS-1'S/DS-0's that will be used for this circuit group. The selections made should mimic the selections made in the section above. Refer to the SS7 - Circuit Group under Signaling topic for more information on this object.
Click on the Channel Groups object which will now have a yellow exclamation point displayed. Click on the Download Resource Tables button and the SS7 Channel Group configuration just created will be sent to the IMG 2020.
Configuring the MWI feature has been achieved. Below is screen capture of the Routing Configuration directory tree when finished configuring.
Additional Information
The MWI feature does not support outgoing SUBSCRIBE message and will not generate an outgoing NOTIFY message with content type application/simple message-summary.
Maximum Number of TCAP dialogs is limited to 32768.
The IMG 2020 will accept incoming NOTIFY request outside of a subscription as long as Event is message-summary and Content-Type is application/simple-message-summary.
The IMG 2020 will return a 484 Subscription does not exist for any NOTIFY requests with Event and Content Types being something other displayed above.
Request for TCAP Service sent from NOTIFY shall contain user information from R-URI and FROM: URI in UPDF format.
Notify shall send a 200 OK or 4xx/5xx response based on response sent from SS7 side.
MWI will not support outgoing SUBSCRIBE.
MWI supports both ANSI and ITU protocol.
Gate Control Layer will create a unique dialog ID for the TCAP request. The ID will be 4 bytes long. First two bytes are used for a counter and last two are used to store NODE ID:
A timer is enabled after Gate Control Layer sends PPL Event Request to SS7. If no Event Indication is received after a timer expires the Gate Control Layer will send a clear to SIP (4xx/5xx).
The IMG 2020 will not generate an outgoing INVITE with TCAP request.
Message Waiting Indicator is supported with SS7 redundancy.
If configuring a service such as CNAM or MWI on multiple IMG 2020 nodes, the SS7 Stack ID's cannot be configured with the same ID. For example, when configuring a IMG 2020 Node 0 with stack ID's 0 and 1 then any other IMG 2020 Nodes configured under any Logical Node can not have any of the stacks configured with the same ID's (0 or 1). By doing so, the TCAP services cannot be configured.