Embedded router/modem with asterisk

I am wondering if it’s possible to originate and terminate calls (pstn to pstn, pstn to mobile, mobile to pstn) without using any voip service providers having just embedded hardware with asterisk on it, maybe just a linksys router modem or any other good brand and asterisk configured on it… No need to use any PC.

I would use this setup to originate and terminate both local and international calls for private use but his does not mean that the other end has to have ATA’s or an asterisk box or even virtual numbers etc…

Thank god open source asterisk exists! I hope it’s possible!