# Ending a call using the Amazon Chime SDK PSTN audio service
<a name="case-5"></a>

You can use the [CreateSipMediaApplicationCall](https://docs.aws.amazon.com/chime-sdk/latest/APIReference/API_CreateSipMediaApplicationCall.html) API to end an outbound call. The API invokes the endpoint of a specified **SIP media application ID**. Customers can control the flow of the call by returning actions to the SIP media application.

In the event of a successful response, the API returns a 202 http status code along with the `transactionId`, which you can use with the [UpdateSipMediaApplicationCall](https://docs.aws.amazon.com/chime-sdk/latest/APIReference/API_UpdateSipMediaApplicationCall.html) API to update an in-progress call.

The following diagram shows the invocations made to the AWS Lambda function endpoint for an outbound call.

![The flow of data when you invoke the CreateSipMediaApplicationCall API. The API invokes a different endpoint when the status of an outbound call changes.](http://docs.aws.amazon.com/chime-sdk/latest/dg/images/sip-api-1.png)


The endpoint configured for the SIP media application is invoked for different statuses of the outbound call. When a customer ands a call, the Amazon Chime SDK invokes the endpoint with a `HANGUP` invocation event type. 

This example shows a typical invocation event for a `HANGUP`.

```
{
    "SchemaVersion": "1.0",
    "Sequence": {{6}},
    "InvocationEventType": "HANGUP",
    "ActionData": {
        "Type": "Hangup",
        "Parameters": {
            "CallId": "{{call-id-1}}",
            "ParticipantTag": "LEG-A"
        }
    },
    "CallDetails": {
        "TransactionId": "{{transaction-id}}",
        "AwsAccountId": "{{aws-account-id}}",
        "AwsRegion": "{{us-east-1}}",
        "SipRuleId": "{{sip-rule-id}}",
        "SipApplicationId": "{{sip-application-id}}",
        "Participants": [
            {
                "CallId": "{{call-id-1}}",
                "ParticipantTag": "LEG-A",
                "Direction": "Inbound",
                 "To": "{{+12065551212}}",
                "From": "{{+15105550101}}",
                "StartTimeInMilliseconds": "{{1597009588}}",
                "Status": "Disconnected"
            }
        ]
    }
}

// if LEG-B receives a hangup in a bridged call, such as a meeting ending
{
    "SchemaVersion": "1.0",
    "Sequence": {{6}},
    "InvocationEventType": "HANGUP",
    "ActionData": {
        "Type": "ReceiveDigits",
        "Parameters": {
            "CallId": "{{call-id-2}}",
            "ParticipantTag": "LEG-B"
        }
    },
    "CallDetails": {
        "TransactionId": "{{transaction-id}}",
        "AwsAccountId": "{{aws-account-id}}",
        "AwsRegion": "{{us-east-1}}",
        "SipRuleId": "{{sip-rule-id}}",
        "SipApplicationId": "{{sip-application-id}}",
        "Participants": [
            {
                "CallId": "{{call-id-1}}",
                "ParticipantTag": "Leg-A",
                 "To": "{{+12065551212}}",
                "From": "{{+15105550101}}",
                "Direction": "Inbound",
                "StartTimeInMilliseconds": "{{1597009588}}",
                "Status": "Connected"
            },
            {
                "CallId": "{{call-id-2}}",
                "ParticipantTag": "Leg-B",
                "To": "{{+17035550122}}",
                "From": "SMA",
                "Direction": "Outbound",
                "StartTimeInMilliseconds": "{{15010595}}",
                "Status": "Disconnected"
            }
        ]
    }
}
```