Thanks Kurun for the support.
I forgot to tell you that i have only one sip device, sorry.
I setup my bt100 as you suggested and i'll check next days the situation.
I don't have the clue to understand what you said:
"If you can do a simple forward from these accounts to
xxxxxx@voxalot.com, your incoming will work far more reliably, as there will be no registration issues between Voxalot and the other VSPs"
my accout is 637400