As Sopock said, you should fill in the form which will then get assessed by the 3CX Regional Sales Manager.What do we need to do in order to get our VOIP server added to list of providers?
You have a point, Sippy is quite popular, I just added it to the form.I think that 1 more answer - Sippy Switch can be added to core infrastructure question.
Founded in 2005, when VoIP was an emerging technology, 3CX has gone on to establish itself as a global leader in business communications.