We have recently setup a SIP trunk to a company to make calls to cell phones and other land lines around the world. I can successfully make outside calls to any country when it is to a land line. As soon as I try to make a call to a cell number the person on the cell phone can hear me, but I cannot hear them.
I have been searching far and wide on the internet to try and find a solution but up to know have not managed to find anything that assisted me with this problem.
Any help and assistance with this problem will be much appreciated. Please let me know what information you require from me to try and troubleshoot this problem.
Here is my trunk config.
fromdomain=(my voip provider)
host=(my voip provider)
10000 – 20000