Technical Questions

If you have a good internet connection, there is typically no difference in the sound quality compared to ISDN and thus a far better than normal analogue landline as well as mobile calls.

In a comparison of IP telephony providers, the Danish leading newspaper Politiken named Redspot the best sound quality. As the conversation is moved over the internet, uptime and quality are always dependent on your internet service provider. Redspot's servers are located in a professionally monitored hosting center so downtime is minimized.

In 2020, Redspot's uptime was more than 99.999%.

Virtually all internet connections in developed countries are so good that they can be used with IP telephony without any problems. Try our test and learn more

Yes, they will just ring at the same time and this no matter where in the world they are. You can thus f.x. have an IP-phone at home, an adapter in the holiday home and an app on your smartphone or laptop when you are on the go.

Note, however, that there are limits to how many simultaneous calls you can have. Please refer to the product description and conditions for your subscription.

Yes, if your device or app supports this, some equipment supports even several simultaneous conversations.

Most of our subscriptions alllow 2 simultaneous calls, however note that 2 simultaneous calls require twice as much internet bandwidth (speed).

Between 30 and 90 kbit/s depending on the CODEC used. This corresponds to between 0.23 and 0.66 MByte/minute. In addition, there is a bit of traffic that the adapter / IP phone / app continuously generates to tell our server where you can be reached so that you can receive calls. Be aware of this if your internet connection is charged according to consumption.

Yes, if you use the G711 / alaw CODEC (standard in all adapters). However, it is also quite sensitive so your internet connection must be very good. In practice, it also depends on how good your fax is and it is impossible to say in advance how well it will work.

A CODEC is the the encoding IP-telephony calls are transmitted with. In general it can be said: The more kbps the better the sound quality. However, the sensitivity to interference also increases with higher kbps.

Both "ends" must support the desired CODEC. For IP-IP calls, such as between two Redspot customers, it is both adapters/ip phones/apps. For IP-PSTN calls such as to the ordinary telephone network including mobiles it is your adapter/IP telephone/app and our PSTN gateway.

Bandwidth requirements for various CODECs supported by Redspots PSTN Gateways