I have ran into a rather weird issue. I have a Siemens 3550 digital phone system that I have installed at a customers location. The dial tone is provided by AT&T and is an IP Flex line.

I received a call from the customer stating that they were not able to forward their siemens digital phones to their company cell phones.

When I arrived onsite I went to the phone and was able to forward it to my AT&T cell phone with no issues. I have tried on various other phones but it works. Its just when the phone is forwaded to a Verizon cell phone it rings 1/2 ring and then get kicked back to the digital phones voicemail.

Any suggestions??????? :confused: