What error did it tell you when you tried to call that number?

I assumed you have reset network settings of the phone when you switched to Koodo? As well, did you put the +1 in front of the Usa number when you called?

Thank you. 

Yes, I put the “1” before the number when I dial.

Usually, there is no audio when I dial. I can see when the hub answers the call, so I enter the code but there is never audio.  I have examined the hub’s record. They have received my calls but there is no audio. Other times, I received messages like, “You are not permitted to dial this number.”   

Other calls to a different teleconference hub work normally

Other calls to other US numbers are normal. 

This number worked fine with Rogers service.

Thaks again for your help.

If it worked with fine with other us numbers, it could be issue the current phone or the us number itself. Have you got another phone to put the Koodo SIM in and test? 

As well, if you know someone with Rogers, you can ask him or her to call the number to test (hopefully they didn't have to pay us long distance fee)

Thanks again. 

The teleconference hub is an HD hub. I suspect that is the problem. Possibly Koodo cannot handle the HD. 

I did try the SIM card in another phone and it worked. 

I have contacted the Teleconference hub company. Possibly they have a Canadian dial-in number and possibly that would work. I also had the Koodo sales person testing various things on my phone. His conclusion was that my phone was weird, but couldn’t offer any other solution. 

Hope springs eternal.