Refer
Refer
During a programmable SIP call, the RCML <Refer> verb instructs Restcomm to initiate a SIP Refer (i.e transfers) towards a SIP infrastructure and handles any NOTIFY messages.
Refer Attributes
| Name | Allowed Values | Default Value |
|---|---|---|
action |
relative or absolute URL |
no default for <Refer> |
method |
GET, POST |
POST |
-
action. The 'action' attribute takes a URL as an argument. When the refer call ends, Restcomm will make a GET or POST request to this URL including the parameters below. If you provide an 'action' URL, Restcomm will continue the current call after the refer finished, using the RCML received in your response to the 'action' URL request. Any RCML verbs occuring after a <Refer> which specifies an 'action' attribute are unreachable. If no 'action' is provided, <Refer> will finish and Restcomm will move on to the next RCML verb in the document. If there is no next verb, Restcomm will end the phone call.
-
method. The 'method' attribute takes the value 'GET' or 'POST'. This tells Restcomm whether to request the URL via HTTP GET or POST.
Refer Action Request HTTP Parameters
The Restcomm parameters passed to your application in its asynchronous request to the Refer action URL. The list of basic parameters can be found in the RCML Voice Request documentation.
The <Refer> request also passes these additional parameters:
| Parameter | Description |
|---|---|
ReferCallStatus |
This provides the application with our understanding (based on SIP NOTIFY messages) of the status of the new call created in response to the REFER. If the REFER fails or the endpoint does not send any NOTIFY requests, this parameter will be omitted. |
ReferSipResponseCode |
The SIP response code received in response to the REFER request Restcomm sends to the SIP endpoint. |
NotifySipResponseCode |
This is the last SIP response code received on the referred leg, as determined by examining the SIP NOTIFY messages. E.g. If the SIP endpoint initiated a new call but received a SIP 404 response due to the target not being found, this parameter would be set to "404". If the REFER fails or the endpoint does not send any NOTIFY requests, this parameter will be omitted. |
Nesting
You must nest the following nouns within <Refer>: SIP
Examples
For examples of how to use the <Refer> verb see below.
Refer to a phone number.
<Response>
<Refer>
<Sip>sip:phone_number@domain.com</Sip>
</Refer>
</Response>
Refer to a phone number with request follow actions.
<Response>
<Refer action="/handleRefer" method="GET">
<Sip>sip:phone_number@domain.com</Sip>
</Refer>
</Response>
