I am looking for a SIP-only provider (no PSTN interconnection needed) for my Obi1062 and Obi200, and am trying to compare between OnSIP, SIP2SIP, and ippi. (PSTN interconnection is already handled by GV and Callcentric.) I would like to try to get more reliable Opus HD calling and (perhaps) encryption via SRTP/ZRTP. Based in USA so slight preference for US-based services.
What are people's experiences with these providers, now that it's 2017? I would rather set up just one account, instead of having one on each service and have to remember or juggle. I have a GetOnSIP account but I understand that
GetOnSIP is deprecated so if I want to use the "latest" features I should migrate to OnSIP Free.