# 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: switch 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 the 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 check any of them\
Save the changes and call the destination number again.
**Alternatively, depending on the firmware:**\
Settings - Telephony - Own phone numbers - connection settings:\
Country: Germany\
Country prefix: leave blank / leave blank\
Area code: leave blank / leave blank\
Save the changes and make an outgoing call.\
If everything works, you can activate the 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:**
* on the 1st router **enable UPnP** and check registration
* on the 2nd router **disable UPnP** and **Port forwarding** set up:\
5060/UDP to the FRITZ!Box IP and 7078-7085/UDP to the FRITZ!Box IP
If a FRITZ!Box is used as the first router, set up the SIP data in the first router.\
For AMV, see the following instructions: **Register a FRITZ!Box with a FRITZ!Box using SIP registrar in order to make calls through it**.
Error message 480: STUN server entered incorrectly, call barring, error in the phone, or DND/reject activated 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 the changes. Test an incoming call.
Call barring may 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 make an incoming call.\
If the FRITZ!Box rings, you know the error comes from the phone.\
DND/reject can be activated 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 set audio codec\
\- You need at least 100 kbit/s downstream and upstream\
\- FRITZ!Box - Settings - System - View: enable 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.) Enable expert view in the FRITZ!Box (System - View - check)\
2.) In the menu go to Settings - Telephony - Internet telephony/own phone numbers\
3.) Tab **Advanced settings/connection**; here **additional connection for internet telephony via DSL (PVC)** disable (remove check)\
\
Variant 2:\
1.) Enable expert view in the FRITZ!Box (System - View - check)\
2.) In the menu go to Settings - Telephony - Internet telephony/own phone numbers - edit sipgate\
3.) **Always log in via an internet connection** enable/check\
4.) Save the changes and check registration\
\
If variants 1 or 2 do not help, it is assumed that you received a FRITZ!Box with its own firmware from your DSL provider/cable provider instead of AVM firmware. Third-party providers such as sipgate are actively blocked in the FRITZ!Box.\
**Solution:** None known, because you usually are not allowed to install the AVM firmware due to it being a loan/rental device.\
**Alternatively:** Use VoIP phones or VoIP analog adapters + analog phone; the FRITZ!Box then functions only 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 displayed with both proxy IP addresses?**\
Then your FRITZ!Box probably has a special firmware from your provider installed 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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