- Does Vonage support SIP REFER?
- Can I transfer calls using SIP REFER?
The Vonage API platform does not support SIP REFER. This can be determined in the Allow header, where "refer" is not listed as a supported method.
As you pay for inbound and outbound calls, if you used REFER for an inbound call to another PSTN party, you would be paying for both the inbound and the outbound calls while being unable to control the call.
We recommend using Voice API for this use case so that you can remain in control of the conversation. You may refer to the links below for further details on Voice API.