> ## Documentation Index
> Fetch the complete documentation index at: https://docs.apifycloud.io/llms.txt
> Use this file to discover all available pages before exploring further.

# Network requirements

> Connectivity required for reliable calls, from the visitor side and the agent side

Click to Call uses real-time voice over the web. Most home and mobile
networks work without any configuration. Corporate networks with strict
outbound policies may need a short allowlist.

## From the visitor's side

Visitors on public networks (home Wi-Fi, mobile data, café, hotel) can
usually place calls without any setup. If quality is poor, it is almost
always a local-network issue — Wi-Fi signal strength, background traffic,
or a congested ISP — rather than a Click to Call–specific requirement.

The [Audio quality guide](/guides/click-to-call/audio-quality) covers
what visitors can do when a call sounds bad.

## NAT and ICE

Most networks use NAT (home routers, office gateways, carrier-grade
NAT on mobile). Click to Call uses the standard ICE negotiation to find
the best media path automatically, and falls back to a media relay when
a direct path isn't possible. No configuration is required for any of
this.

## HTTPS is mandatory

Browsers only allow microphone access on pages served over HTTPS. If
you embed the widget on your own site, your page must be HTTPS. The
hosted widget URL we provide is always HTTPS.

## What's next

<CardGroup cols={2}>
  <Card title="Audio quality" href="/guides/click-to-call/audio-quality">
    Understanding the Network indicator and how to act on it.
  </Card>

  <Card title="Troubleshooting" href="/guides/click-to-call/troubleshooting">
    Specific fixes when calls fail despite meeting the requirements.
  </Card>
</CardGroup>