# Troubleshooting

On this page you can find some additional info which can help during troubleshooting.

## Network

The network speed and bandwidth takes a crucial role in video delivery. Therefore it's recommended to verify network settings when facing play-out issues.

Some known issues and advisable configuration items:

| Topic                                                  | Description                                                                                                                                                                                                                                                                                                                                                                                    |
| ------------------------------------------------------ | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| What is the list of FQDNs the player is using?         | <https://theolive-anywhere.global.ssl.fastly.net><br /><https://theolive.global.ssl.fastly.net><br /><https://cdn.tla-prd.theostream.live><br /><https://discovery.theo.live><br /><https://theo-insights-prod-5cb0.ew.r.appspot.com><br /><https://time.akamai.com>                                                                                                                           |
| Why is my corporate VPN having issues during playback? | In the past, we have seen 2 possible reasons for poor VPN playback:<br />- The VPN might have a security gateway that does packet inspection. It is very important that all domains listed above are whitelisted so network requests are allowed to go through the VPN at real-time speeds.<br />- The overhead of the VPN connection does not meet the bandwidth & network stability to play. |
| Packet inspection                                      | Packet inspection software (e.g. Zscaler) can have a negative impact on play-out causing buffering and stalling of the stream.                                                                                                                                                                                                                                                                 |

## Playback

| Topic                                                                     | Description                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |
| ------------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| Why do I get HTTP `403` responses while token-based security is disabled? | Even when [token-based security](https://docs-preview.optiview.dolby.com/pr-861/theolive/distribution/security/token-based-security.md) is disabled, any JWT included in a request (via the `Authorization` header or the `token` query parameter) is still validated for well-formedness and expiry. An **expired** or malformed token results in an HTTP `403`, even though the same request without a token would succeed. Make sure your player stops attaching stale tokens. |