Hi, I'm a client of Rogers Canada and have been using UMA in Montreal and Ottawa on multiple sites (Mac Airport Express Router, using a Macbook as a router, etc). Worked flawlessly all the time. I'm presently in Brazil and the main reason for getting my 8900 has let me down. I tried while connected to a private LAN on a Cisco modem (default settings..etc) in Rio, now tried in Belem; same idea: connected to the Net with no problem, but no UMA symbol and if I try to call with the radio off, I get a primitive busy signal. Any ideas would be welcome. I obviously have better things to do than play around with my BB in Brazil, but still would be nice to be able to call back home for "free" for Xmas rather than spending 5 or 8 $ a minute (thank's Rogers; at that price, I should have bought a satellite phone!) ;)

I do not know for sure, but Rogers may disallow UMA usage when the request comes from an IP address not located in Canada.

It is not a free solution, but sign up for a Canadian VPN with blacklogic.com. You'll need to run the connection through your Macbook. If Rogers is using IP filtering, it will get you around it. If Brazil is using VOIP blockiing it will also help, but most blocking technology doesn't target UMA. UMA doesn't have huge market penetration and the protocol looks IPSEC.

Blacklogic isn't the only VPN service offering a Canadian server. It is just the one I knew off my head.

That's a fantastic idea!

One thing I discovered the other day is that certain DNS servers can prevent UMA. I was using Google's DNS servers on my home router and could not make a UMA connection. I changed them back to be received from the ISP's DHCP server and it started working again.