[Serusers] SIP Service Providers supporting Windows Messenger 4.6

[Michael Kendall]

Hi,

Reading the SERusers digest for a few months
has allowed me to read about a lot of very complex
and specialized problems.  It's a bit intimidating.

Although I might some day want to learn to administer
a Linux system and run my own SER server, at this
point I would rather just become a paying customer on
someone else's SER server.

Many of the list participants
are clearly professionals operating
large SIP service providers.  But none of these
professionals have identified their organizations
clearly enough to let me become their customer.
Perhaps because the traditions of the list prohibit
users from advertising their commercial services.

Can someone please give me a recommendation of a
SIP service provider which has good service and
reasonable pricing.  I need a service which will
allow me to call between two computers,
each running Windows Messenger 4.6/4.7 .

I am aware that the latest version,
Windows Messenger 5.1 does not allow connecting
to third party service providers, and that is the
reason that I am using the older versions.
The Microsoft site does not tell me how to configure
version 5.1 for STUN or for symmetric NAT.

Every link that I have found for downloading version 4.6
points me back to the download page at microsoft.com,
and microsoft has actually removed the file so all
I get from them is a polite apology.  Fair enough.
So here is an interesting legal question that I suspect
a lot of you SER wizards will know the answer to:    
Is it illegal for third parties sites to publicly offer
the download of version 4.6 after microsoft has
chosen to stop offering it?  It was after all being
given away free by Microsoft a short time ago.

I am aware that freeworlddialup.com (FWD)
is a good no-cost SIP service provider.
Does FWD use SER as their server software?
The latest version of FWD offers several options for
User Agent software, but none of these UAs include
a whiteboard feature, which I need for my tutoring
service.  

Therefore, I need a SIP Service Provider
which supports Windows Messenger 4.6/4.7
and has some configuration instructions
for this particular UA.  
Hopefully the config instructions will tell me how
to set Messenger up for STUN when I have a standard NAT,
and for mediaproxy when I encounter a symmetric NAT.

Googling for "SIP Service Provider" and "Windows Messenger 4.6"
has led me to a lot of dead ends and out-of-date pages,
such as the "old FWD site" at pulver.com which has detailed
instructions for configuring Messenger 4.6, but the
instructions no longer work.
"Service provider temporarily unavailable". (permanently)

Can anybody offer a Service Provider recommendation
or volunteer to take me on as a customer?

thanks

Michael Kendall