Hi. My company recently started trial of 3CX professional edition and one of our requirement is to be able to support smartphones of employees at remote coal mine sites (Indonesia) where often the best data connection they have is 2G/Edge, with a realistic bandwidth of 40kbps. When using the GSM-FR codec the voice quality is not good enough to be useful. i would like to try G729 as I understand this is more efficient than GSM, but I cannot see this as an option when I look at the phone provisioning tab, I can only see G711A, G711U, G722 and GSM. I have googled around and read that G729 is supported by 3CX but maybe only as a trunk connection. Is it possible to use G729 as 3CX codec for smartphone client, and how can this be done.