> For the complete documentation index, see [llms.txt](https://help.sipgate.de/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://help.sipgate.de/cloud-telefonanlage/en/using-sipgate/telefonie/was-bedeuten-die-telefonie-fehler-codes.md).

# What do the telephony & error codes mean?

Overview of sipgate telephony error codes (401, 403, 486, etc.) with explanations and solution notes.

#### The following error codes occur most frequently:

| **401** Login details incorrect | The username (SIP ID) or password (SIP password) is incorrect.                                                        |
| ------------------------------- | --------------------------------------------------------------------------------------------------------------------- |
| **404** Number unknown          | The phone number does not exist, is not assigned to a line, or is not configured in the callee's device/phone system. |
| **486** Busy                    | The remote party reports that the subscriber is busy.                                                                 |
| **487** Hung up                 | The usual signal when the remote party hangs up.                                                                      |

#### Other frequently transmitted codes:

| **100** Call connecting               | An attempt is being made to connect the call. This code is part of the normal call setup process.                                  |
| ------------------------------------- | ---------------------------------------------------------------------------------------------------------------------------------- |
| **180** Ringing signal                | The ringing is signaled by the callee's device.                                                                                    |
| **183** Connection setup              | The connection is currently being established. A ringing tone or announcement may be heard.                                        |
| **200** OK                            | The call was answered, or the device has registered with the server.                                                               |
| **301** Permanently forwarded         | A permanent forwarding to another destination is set up.                                                                           |
| **302** Temporarily forwarded         | A temporary call forwarding is set up on the callee's phone.                                                                       |
| **400** Bad request                   | The request contains invalid parameters. This usually means that you entered data into the wrong field of the phone configuration. |
| **403** Not allowed                   | The subscriber is not authorized to make this call.                                                                                |
| **407** Proxy authentication required | For outgoing calls, the phone must authenticate itself to the server.                                                              |
| **408** No response (Request Timeout) | Usually occurs when your router or firewall only partially or not at all forwards data packets to the phone.                       |
| **480** Temporarily unreachable       | Received, for example, when the callee has enabled DND/Do Not Disturb.                                                             |
| **481** Call does not exist           | Rarely happens, mostly when a status message did not reach its destination.                                                        |
| **482** Loop routing detected         | Loop routing often created by forwarding (A ➔ B ➔ A).                                                                              |
| **488** Unacceptable call attempt     | Occurs when the codec used by the device, the encryption or transmission method (e.g. video) is not supported.                     |
| **500** Server error                  | General server error.                                                                                                              |
| **502** Wrong gateway                 | The gateway (server) in the SIP request is incorrect.                                                                              |
| **503** Service not reachable         | The server's SIP service is temporarily unavailable.                                                                               |
| **603** Rejected                      | The remote party rejected the call. This can be done manually or automatically.                                                    |


---

# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation by asking a question.

Perform an HTTP GET request on the following URL with the `ask` and `goal` query parameters:

```
GET https://help.sipgate.de/cloud-telefonanlage/en/using-sipgate/telefonie/was-bedeuten-die-telefonie-fehler-codes.md?ask=<question>&goal=<user_goal>
```

`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is what the user is ultimately trying to achieve, the reason they need the answer. Sharing it helps GitBook give you a better, more relevant answer. A goal is most helpful when it describes the outcome the user wants rather than restating the question. For example, with `ask=how do I create an API token`, a goal like `automate deployments from our CI pipeline` lets GitBook tailor the answer to that use case.

The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.