> 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/allgemeine-losungen-beim-telefonieren-mit-sipgate/was-bedeuten-die-fritzbox-fehlermeldungen.md).
# What do the FRITZ!Box error messages mean?
If registering the sipgate data in your FRITZ!Box does not work or calls are rejected, you can find the exact error message in the **FRITZ!Box** under **settings**, then **System**, **Events** and then under **Telephony**.
Error message 401: SIP ID, SIP password and/or SIP server data incorrect
{% hint style="warning" %}
Exception: IPv6 - Hitron Modem - FRITZ!Box
{% endhint %}
\ Problem: Hitron does not forward the 401 requests correctly to the FRITZ!Box\ Solution: convert Hitron to bridge mode
Error message 403: server data incorrect
Settings - Telephony - Own phone numbers - edit sipgate: **other provider** select\
Registrar: sipgate.de\
Proxy server: sipgate.de\
Save changes and check registration
Error message 404: destination number dialed incorrectly or FRITZ!Box dials incorrectly
Settings - Telephony - Own phone numbers - edit sipgate: **other provider** select\
Registrar: sipgate.de\
Proxy server: sipgate.de\
Automatic prefixes: 49, 0, 00, XXX do not tick any of them\
Save changes and call the destination number again.
**Alternatively, depending on the firmware:**\
Settings - Telephony - Own phone numbers - connection settings:\
Country: Germany\
Country code: leave blank / leave blank\
Area code: leave blank / leave blank\
Save changes and make an outgoing call.\
If everything works, you can activate automatic prefix in the sipgate account - Settings - Telephony
Error message 408: timeout
Settings - Telephony - Internet telephony/Own phone numbers - Advanced settings/connection settings:\
Keep port forwarding of the Internet router for Internet telephony active: enable\
Keep port forwarding active every: 30 seconds
**If a router is used in front of the FRITZ!Box:**
* in the 1st router **enable UPnP** and check registration
* in the 2nd router **disable UPnP** and **port forwarding** set up:\
5060/UDP to the IP of the FRITZ!Box and 7078-7085/UDP to the IP of the FRITZ!Box
If a FRITZ!Box is used as the first router, set up SIP data in the first router.\
At AMV you can find the following instructions for this: **Register a FRITZ!Box on a FRITZ!Box with SIP registrar to make calls via it**.
Error message 480: STUN server entered incorrectly, call barring, error in the phone, or DND/rejecting active on the phone
**settings** - **Telephony** - **Own phone numbers** - **edit sipgate**: **other provider** select\
proxy: sipgate.de\
registrar: sipgate.de\
STUN server: leave blank, if visible\
Save changes. Test an incoming call.
Call barring could be active and should be disabled:\
Link to AVM: [Call barring](http://avm.de/service/fritzbox/fritzbox-7270/wissensdatenbank/publication/show/142_Rufsperren-fuer-ankommende-und-ausgehende-Anrufe-z-B-0900-Nummern-einrichten/)
Disconnect the phone from the FRITZ!Box and call in.\
If the FRITZ!Box rings, you know the error is coming from the phone.\
You can activate DND/reject on the phone. All incoming calls will be rejected.
Error message 488: Not acceptable here
\- Either an audio codec is being used that we do not support, or there is too little bandwidth available for the currently configured audio codec\
\- You need at least 100 kbit/s download and upload\
\- FRITZ!Box - Settings - System - View: activate expert view\
\- **settings** - **Connections** - **Own phone numbers** - **edit sipgate** Provider: **other provider**\
Enable: provider requires G.726 according to RFC 3551
Error message: timeout no response
Variant 1:\
1.) Activate expert view in the FRITZ!Box (System - View - check)\
2.) In menu Settings - Telephony - Internet telephony/Own phone numbers, switch to\
3.) Tab **Advanced settings/connection**; here **other connection for Internet telephony via DSL (PVC)** disable (remove checkmark)\
\
Variant 2:\
1.) Activate expert view in the FRITZ!Box (System - View - check)\
2.) In menu Settings - Telephony - Internet telephony/Own phone numbers - switch to - edit sipgate\
3.) **Always register via an Internet connection** enable/check\
4.) Save changes and check registration\
\
If variants 1 or 2 do not help, it can be assumed that your DSL/cable provider has supplied you with a FRITZ!Box with its own firmware instead of AVM firmware. Third-party providers such as sipgate are actively blocked in the FRITZ!Box.\
**Solution:** None known, as you usually are not allowed to install the AVM firmware because it is a loan/rental device.\
**Alternatively:** Use VoIP phones or VoIP analog adapter + analog phone; the FRITZ!Box then only acts as a router without telephony.
Error message: DNS error
FRITZ!Box - Settings - Telephony - Own phone numbers - edit sipgate:\
Provider: **other provider**\
User name: SIP ID\
Password: SIP password\
Registrar: sipgate.de\
Proxy: 217.10.79.9\
Now save the entered data.
**Is the error message "DNS error" still shown for both proxy IP addresses?**\
Then it is likely that a special firmware from your provider is installed on your FRITZ!Box and the FRITZ!Box cannot be used as a VoIP router with **third-party providers** such as sipgate.\\\\
{% hint style="info" %}
**Note**: Alternatively, you can use your FRITZ!Box as a router without VoIP with sipgate by using\
\- a VoIP phone,\
\- a VoIP adapter with an analog phone\
\- or a VoIP software solution behind the FRITZ!Box.
{% endhint %}
---
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