Place a Twilio call on hold and retrieve it later

Question

I am creating a Twilio application using JavaScript SDK.

I want to implement call hold functionality but I am having trouble implementing it.

What is the process to put a call on hold, when it is initiated by the soft-phone? Also, what is the process when the soft-phone is receiving the call?

Answer 1

Twilio evangelist here.

There are different ways to place a call on "hold". Normally it does not matter whether the call originated from Client or from a PSTN number, the process is generally the same:

1. Provide Twilio some TwiML that places the call into "hold" then
2. when you are ready, use that calls CallSid and the REST API to redirect the live call to a new experience.

Now, for placing the call on "hold" there are a couple of options I can suggest:

One is to use the <Play> verb and set the loop attribute to zero, which will tell Twilio to loop over that audio indefinitely. When you are ready to move the call out from "hold", you simply redirect the call.

Another option is to use the <Enqueue> verb and place the call into a call queue. Then when you are ready simply redirect that call back out of the queue to a new experience.

Hope that helps.

Answer 2

When the user of the soft phone press Hold you can use the REST API to update that call, sending the call to a queue.

You can do that redirecting the call to a TML file with the <Enqueue> tag.

To retrieve the call to the soft phone you can use the CallSid to update the call and sending it back to the soft phone user.

I already implemented that feature in my app, so let me know if you need some help.