Question : NSA 240 Site to Site VPN - VoIP server on 1 side some phones on the other

Currently my company as 3 offices. 2 are located within 100 yards of each other (across a street) and the other about 20 miles away. I've got 3 Sonicwall NSA 240's (1 at each site) that are connected through IPsec VPN. The main office has a T1 for data and a T1 for voice. That's also where our Fonality PBXtra (VoIP Server) is housed. 90% of our VoIP traffic is generated at the main office from our call center.

Our most remote office has 5 or 6 phones (basic polycom's) and are rarely used. Voice quality isn't great....but it does the job and it was easy to setup. I just had to type in the username and password string into the phones display and they would register across the VPN to our Fonality Server.

I'm looking to add 3 or 4 phones at the site across the street from our main office. I bought 5 Linksys SPA921 SIP phones. They have a crazy web gui interface for configuration and I'm not sure what settings need to be changed. They didn't come with any documentation or setup guide. Anybody have any tips on what settings I need to change? Any brand specific items that might be different from our other polycom phones? Any experience with the Linksys SPA900 series?

Answer : NSA 240 Site to Site VPN - VoIP server on 1 side some phones on the other

If you have a sonicwall in front of Comcast with a VPN configured, the QoS will not be dropped.  Since the traffic is encrypted, they can't modify it as QoS will be within the encrypted traffic.  Is that how things are configured?  Am I understanding that you have sonicwall VPNs at ALL the remote sites?