I have a Gigaset N300A IP DECT phone that can be hooked up both to a landline and to Ethernet for VoIP. I have been using it for about 6 years and it has worked well with a number of SIP providers: DIDLogic, Localphone, VoIPFibre, VoipVoip. It is connected via Ethernet directly to my VDSL router.
For the last few months, I have used the last three of the providers mentioned above and they have all been working fine. Then suddenly a week ago, all three stopped working at the same time. In the admin panel of the N300A IP, it says "Registration failed" for all three.
I made no changes to the N300A IP at the time, nor did I make any changes to the router.
I have since tried:
- Rebooting the N300A IP (no difference)
- Disconnecting and reconnecting the N300A IP (no difference)
- Updating the firmware of the N300A IP (which worked, showing that it is connected to the Internet, but it did not solve the issue)
- Re-entering the SIP settings for one of the accounts (no difference)
- Using my VoIP accounts using a soft phone on my Android phone via the WiFi of the same router that the N300A IP is connected to (this works fine)
In the log file from my router, I notice errors such as:
DNS name resolution failure (_sip._tcp.localphone.com)
DNS name resolution failure (_sip._tcp.proxy.localphone.com)
DNS name resolution failure (_sip._udp.sip1.voipfibre.com)
DNS name resolution failure (_sip._tcp.sip1.voipfibre.com)
Since I have never looked at the log before, I cannot say if these errors are new and related to the issues with registration. However, as an experiment, I changed the DNS server settings on the router from 192.168.1.1 to OpenDNS servers, but this also did not resolve the problem.
I am puzzled by the underscores in the DNS errors above - why is the N300A IP looking up _sip._tcp... instead of sip.tcp... ?
Any advice most appreciated!