This Service is used to terminate a Session. The Server takes the following actions when it receives a CloseSession request:

1. It stops accepting requests for the Session. All subsequent requests received for the Session are discarded.
2. It returns negative responses with the StatusCode Bad_SessionClosed to all requests that are currently outstanding to provide for the timely return of the CloseSession response. Clients are urged to wait for all outstanding requests to complete before submitting the CloseSession request.
3. It removes the entry for the Client in its SessionDiagnosticsArray Variable.

When the CloseSession Service is called before the Session is successfully activated, the Server shall reject the request if the SecureChannel is not the same as the one associated with the CreateSession request.

Table 19 defines the parameters for the Service.

Table 19 – CloseSession Service Parameters

Name	Type	Description
Request
requestHeader	RequestHeader	Common request parameters (see 7.33 for RequestHeader definition).
deleteSubscriptions	Boolean	If the value is TRUE, the Server deletes all Subscriptions associated with the Session. If the value is FALSE, the Server keeps the Subscriptions associated with the Session until they timeout based on their own lifetime.
Response
responseHeader	ResponseHeader	Common response parameters (see 7.34 for ResponseHeader definition).

Table 20 defines the Service results specific to this Service. Common StatusCodes are defined in Table 182.

Table 20 – CloseSession Service Result Codes

Symbolic Id	Description
Bad_SessionIdInvalid	See Table 182 for the description of this result code.