My replies in blue;
Using the accounts previously mentioned as examples in the following answers;
1. You seem to have blinkered understanding of what is possible with VoIP, provided you use suitable equipment!
Response: I am fully aware that you can have several sip accounts on appropriate hardware. And yes a dial plan will automatically choose the best route to use.
Right, so dial plans do not need explaining ...
2. Many people use multiple VoIP accounts, sometimes dialling out on 1 account using the number of another account as CLI.
Response: Please elaborate on how this is achieved.
See Answer#3 and Answer#4 below ...
3. So the OP could do as I suspect @Michael_Chare is suggesting, i.e. using his old BT number ported to Voipfone as CLI for an outgoing call to a UK mobile via Discountvoip at around a third of a penny per minute and no setup charges. Any returned calls would be received on the Voipfone line.
Response: Yes Voipfone will port in his cherished number and outgoing calls will indeed show that number. Please provide chapter and verse of the configuration that allows the call to be routed through Discountvoip to a UK mobile but displaying the cherished number. You quote a call cost to a UK mobile using this method of a fraction of a penny. Seen on the Discountvoip site is two prices for calls to UK mobiles. It is not clear when the higher rate kicks in at 14 ppm.
Edit: I forgot to mention, all the calls to Mobiles that I've made via Discountvoip have been at the lower rate so I don't know when the higher price is charged.
The OP is probably new to VoIP and perhaps not understood the configuration that would be necessary.
After opening a Discountvoip account, go to the settings page on their site and enter any telephone number that you 'own' to be used as CLI. You will then receive a call from their system to the number entered and a 4 digit confirmation code will be spoken. You then enter that code into the web page and that's it, job done, number available for CLI, confirmed.
Depending on which VoIP device you wish to use this on may mean transposing the number for your AccountName in the UserName field and entering the AccountName in another field such as AuthenticationName.
4. All that (with automatic routing as suggested) is handled seamlessly by equipment such as the Gigaset N300 as mentioned.
Response: Well I have the same hardwire, so your response that shows the configuration required to achieve this would be of interest. Your knowledge is greater than mine, so sharing it would be most useful.
You claim to have the same hardware, so therefore it shouldn't be too difficult to use a dial plan as you mention in your Response#1 above. e.g. as @Michael_Chare suggested, simply route numbers beginning 07 via the Discountvoip account.
FTTP 80/20 Mbps
Edited by Rastus (Sun 03-Feb-19 19:10:13)