Thanks for your post, we are looking to offer hosted PBX and business telephone VOIP. We will need toll free DID's as well as local DID's for as many locations as we can.
We would like to use SIP, however if you have any recommendations or arguments why either/or would be better, I am all ears.
Thanks for your reply.
For Local DIDS, if you are going to use a lot of minutes then better look at Flat Channel ( most provider can give you ~ $15 a channel for unlimited inbound. Take a look at http://www.ipcomms.net
The best setup would goes for at least 2,3 DIDs provider + 2,3 different SIP trunk provider.
If you are using Asterisk core then I recommend for IAX but SIP will work fine also.
For the route/trunking. What's your's focus-destination? and how much minutes that you are going to push ? More minutes the lower rate you can get. Try to find white route with high ASR and ALOC. If you are looking US domestic only then there a a lot of providers out-there, most of them can provide you with nice rate but make sure asking them about support! I can find very few provider who can have redundant network and 24/7 support.