Twilio可编程语音开发疑问：通话音频接收与双向通话TwiML配置求助

Hey there, let’s work through your Twilio issues— I’ve tackled similar setup snags before, so here’s what I’d suggest:

First off, you don’t have to use Zoiper (or any softphone) to fix this, but let’s rule out common culprits first:

• Verify your "from" number: Make sure the from parameter in your code is a Twilio-assigned phone number. If you’re using a regular personal mobile/landline number here, Twilio’s routing restrictions will break audio delivery— this is a super common gotcha.
• Fix your empty TwiML: Right now you’re passing an empty <Response></Response> which means Twilio has no audio to send to the caller once they pick up. Even for testing, add a simple <Say> to confirm audio works:

  <Response><Say>Hello, this is a test call. Can you hear me?</Say></Response>
  

• Check your caller’s device: If you’re using a physical phone, double-check network signal. If you do use a softphone like Zoiper, ensure it’s configured with standard SIP settings (but again, this shouldn’t be required if you’re using a Twilio number as the caller ID).

The core of two-way calling with Twilio is the <Dial> verb— it connects the active caller to another number. Here’s how to implement it properly for your use case:

Basic two-way call setup #

When you use CallResource.Create, Twilio first calls the number in the to parameter (your test caller). Once they answer, Twilio executes the TwiML you provide. To connect them to the other party, use <Dial> like this:

string accountSid = mySid; 
string authToken = myToken; 
TwilioClient.Init(accountSid, authToken); 
var call = CallResource.Create( 
    from: new Twilio.Types.PhoneNumber("+44YOUR_TWILIO_NUMBER"), // Use your Twilio-assigned number here
    to: new Twilio.Types.PhoneNumber("+44YOUR_TEST_CALLER_NUMBER"), // The number that will initiate the call (your test line)
    twiml: new Twilio.Types.Twiml("<Response><Dial>+44999988888</Dial></Response>") 
);

Here’s the flow:

1. Twilio calls your test caller number (to parameter)
2. You answer the test call
3. Twilio automatically dials the target number (+44999988888) via the <Dial> verb
4. When the target answers, both parties can talk bidirectionally

Add extra controls (optional) #

If you want to add pre-call prompts, recording, or other features, extend the TwiML:

<Response>
  <Say voice="alice">Please hold while we connect you to your party.</Say>
  <Dial record="record-from-ringing-dual" timeout="30">
    <Number>+44999988888</Number>
  </Dial>
  <Say>If you're hearing this, the call didn't connect. Please try again later.</Say>
</Response>

• record="record-from-ringing-dual" records both sides of the call
• timeout="30" hangs up the dial attempt after 30 seconds if no answer
• The final <Say> plays if the dial fails

内容的提问来源于stack exchange，提问作者Peter Bannister