I have a client who has me looking into Hosted VOIP solutions. They have four sites, about 15 phones total, and nothing too unusual in their requirements.
My concern has to do with getting internet service from an internet provider that is not the same company that provides the Hosted VOIP. More specifically, the ISPs with whom I have spoken can't guarantee QoS all of the way to the Host site.
The Host companies tell me that it usually works just fine. They will do tests from our site to theirs for a few days or longer to ensure that communication integrity is reasonable to expect.
The big concern that I have is that there is no assurance that there won't be a problem with traffic prioritization in the future. The ISP will take the stand that they never guaranteed it in the first place and the Host vendor will say that there is nothing they can do about it.
I will ensure that all of the internal switches and routers and such will support QoS.
One solution for this is to have the ISP do the VOIP Hosting. We are getting a quote for that, but I am expecting a substantial price difference.
Should I have these concerns? Is anyone experiencing these problems?