Hey Philippe, install ExpressTalk Business Edition using one of the VoIP lines you want to use to test if my above request may be able to help.
I call into ExpressTalk Business Edition (the VoIP with a PSTN number) using my cell phone.
Then I answer the call with ExpressTalk Business Edition.
Next I press the conference button, dial my land line, press call, then press the conference button again (before or after I answer the land line).
Then I answer the land line, and voila, I can talk from my cell phone to my land line with no loss, save a few seconds lag on the return of voice from the land line to the cell phone.
If this works using your VoIP carrier, then the customization above should definitely help in your business and in general.
I'll do my best to get NCH to get ExpressTalk Business Edition's conference feature into IVM standard, so all may benefit. I've been speaking with IVM developers, but can't seem to help them understand. Here's my change order request:
Regarding IVM:
1. request: allow IVM to conduct conference calls (remaining online for the duration of the conference)
2. example: as there is an OGM transfer option, there would be an OGM conference option
3. relief: this allows a workaround to some VoIP gateways inability to transfer calls but have the ability to conference calls
4. desirability: other customers express this request on the IVM, ExpressTalk, and Axon forums over the past 18 months
5. model: ExpressTalk BE effectively utilizes this request in its confrencing functionality
If anyone else wants this feature, let IVM know by posting here.
And if you can better explain the above change order to IVM developes, by all means post it as my English may not be so good.