There are four types of REST methods

• connect
• direct invocatons
• event
• incoming invocations

The connect method determines behavior of all other methods.
The connect method should return in the response only those data that it really received from WCS with an exception of the case when some field in the response should be explicitly overwritten or another status must be returned.
Other methods are recommended to return in the response only those data that they received with an exception of the case when some field in the response should be explicitly overwritten or another status must be returned.
All methods should return the 200 OK HTTP status with an exception of the case when another status should be explicitly returned, for example, 403 Forbidden.

Direct invocations from WCS JavaScript API

These events may be interrupted by web server:

• call - outgoing call may be forbidden
• answer - incoming call answer may be forbidden
• hold - call hold may be forbidden
• unhold - call hold may be forbidden
• transfer - call transfer may be forbidden
• sendDTMF - DTMF sending may be forbidden
• sendMessage - message sending may be forbidden
• sendIMDN - IMDN sending may be forbidden
• subscribe - SIP subscription may be forbidden
• sendXcapRequest - XCAP sending may be forbidden
• publishStream - stream publishing may be forbidden
• playStream - stream playing may be forbidden
• playHLS - HLS stream playing may be forbidden
• playRTSP - RTSP stream playing may be forbidden
• OnDataEvent - data sent may be rejected
• sendBugReport - bug report sending may be forbidden

These events may be interrupted, but it is impractical:

• hangup - call hangup may be forbidden
• unPublishStream - stream unpublishing may be forbidden
• stopStream - stream stopping may be forbidden

Events that have already happened and can not be forbidden by web server

This events can not be cancelled by web server because the event has already happened on WCS side, and only notification is sent to web server

• ConnectionStatusEvent
• RegistrationStatusEvent
• CallStatusEvent
• TransferStatusEvent
• MessageStatusEvent
• SubscriptionStatusEvent
• XcapStatusEvent
• StreamStatusEvent
• DataStatusEvent
• BugReportStatusEvent
• StreamKeepAliveEvent

Incoming calls

Incoming calls may be interrupted by web server. WCS notifies caller in this case.

• OnCallEvent - incoming call
• OnMessageEvent - incoming message
• OnTransferEvent - incoming call transfer

If REST method was initiated using REST API

If REST method of any type was initiated using REST API, it should not be declined by web server.

Actions taken when web server interaction error is occurred

An interaction error occurs when web server returns status other than 200 OK, or some error prevents access to web server. Actions taken depending on restOnError field of restClientConfig object and method type, described below:

Actions taken when other error is occurred

When SIP status 4xx, 5xx, 6xx is received, or other error not concerning to REST is occured, an appropriate event will be initiated with FAILED status and error description in 'info' field. This event will be delivered to web server and then to client according to the rules defined in restClientConfig.

For example, if SIP server returns 403 FORBIDDEN on outgoing call then CallStatusEvent event with status='FAILED', info='SIP 403 FORBIDDEN' and sipMessageRaw='the original SIP message' will be sent to the web server and to the client.

If the error can not be correlated with any of the existing events then ErrorEvent event will be initiated with error description in 'info' field.

Let’s review one method of each type (the remaining methods behave similarly within the corresponding type).

• Type 1 - the connect method
• Type 2 - the direct invoke
• Type 3 - the event
• Type 4 - the incoming call