Yes. Note that these are just basic SIP calls and may come from a wide range of IP addresses. More advanced features including authentication, registration and fixed SIP addressing can be provided if you ask us to treat the hostname you're calling as an outbound PSTN Provider. Please contact support to arrange. Note also that Aculab Cloud does not implement Network Address Translation (NAT) traversal. It's designed to call SIP endpoints on the public internet, such as telco gateways or SIP gateways at the edge of call centres.