Achievable with Asterisk?

I was looking for a hosted PBX to simplify my offices, but since no providers are actual international switchers I’m now looking into Asterisk as a solution.

Scenario:

I have Medium sized offices in California, New Jersey and London

I have Small offices in New York, Paris and China

I would like to have the ability for all offices to call each other over IP for free, connect to local PSTN lines for inbound and outbound calls, as well as all of the general features like follow me and group ringing.

Is this possible with Asterisk? It seems like it is, but I’m having trouble finding information on how I would implement this globally.

Any help, advice or constructive criticism is welcome.

Yes its possible.

You can interconnect all the offices(servers) via IAX2 trunk to communicate via Internet, obviously you need a good bandwidth and some QoS in your internet acces.

You can connect to the pstn via TDM cards or digital card depend on your needs, even with a sip trunk.

And yes, asterisk can make ring groups, queue, autoattendant, voicemail and so on.

I have IAX2 trunks connecting offices in Kansas, California, and Mexico. Though the “free” part is nice, the big reason we do it is so we have 4-digit direct dialing.
We do it with no QoS but do have reasonable bandwidth and it works well. Overseas may introduce a lot more latency - haven’t done much of that.