Hi,
Does this happen for all users that are connected externally? I would like to confirm if the call is successful when the use is connected internally and then call or receive a external PSTN number.
Please double check if the Mediation is associated with Edge Pool properly. The Edge pool used by the Mediation Server will be the same Edge pool associated with the Front End pool where the Mediation Server is collocated on.
Kent Huang
TechNet Community Support
