Supported Providers

UpVoot works with any telephony provider that supports WebSocket audio streaming. The following guides cover the most common Indian and global providers.

Exotel

Exotel supports WebSocket streaming via its Applet builder. This is the recommended provider for Indian DLT-licensed outbound calling.

1. Log in to the Exotel dashboard and navigate to App Builder.
2. Create a new Applet or edit an existing one.
3. Add a Connect to WebSocket widget.
4. Set the WebSocket URL:

   wss://api.upvoot.com/voice/<your-api-key>

5. Set audio encoding to PCM / L16, sample rate 16000, channels 1 (mono).
6. Connect the applet to your Exotel phone number under Phone Numbers → Incoming / Outgoing.
7. For outbound campaigns, use the Exotel Campaigns API to initiate calls — Exotel handles DLT header injection automatically.

Twilio

Twilio supports WebSocket streaming via its Media Streams feature on TwiML Voice calls.

1. In your TwiML Voice URL handler, return a <Stream> verb:

   <?xml version="1.0" encoding="UTF-8"?>
   <Response>
     <Start>
       <Stream url="wss://api.upvoot.com/voice/sk_live_YOUR_KEY" />
     </Start>
     <Pause length="60"/>
   </Response>

2. Note: Twilio Media Streams send audio as base64-encoded mulaw (μ-law, 8kHz) by default. UpVoot will automatically convert from mulaw to PCM — no action needed.
3. To send audio back to the caller, use Twilio's Media Messages API or the bidirectional stream protocol (Twilio Media Streams v2).

Airtel IQ

1. In the Airtel IQ portal, navigate to Voice → Flows.
2. Add a WebSocket Bridge step to your call flow.
3. Configure:

   WebSocket URL: wss://api.upvoot.com/voice/<api-key>
   Audio: PCM 16kHz mono

4. Attach the flow to your virtual number under Phone Numbers.

Plivo

1. Use Plivo's PHLO (Plivo High-Level Objects) or PHLO-XML:

   <Response>
     <Stream keepCallAlive="true"
             bidirectional="true"
             audioTrack="both">
       wss://api.upvoot.com/voice/sk_live_YOUR_KEY
     </Stream>
   </Response>

2. PCM 16kHz mono is supported natively by Plivo streams.

Any SIP gateway

If your provider supports WebSocket audio bridging (sometimes called "WebSocket SIP" or "media forking"), point it at:

wss://api.upvoot.com/voice/<api-key>

Requirements:

• Standard WebSocket (RFC 6455)
• Binary frames for audio (PCM L16 16kHz mono)
• Bidirectional streaming (full-duplex)

Missing a provider?

Email hello@upvoot.com and we'll add a guide within 48 hours.