I use a SIP provider for the landline at home. When on vacation I want to be able to make outbound calls with my landline number. I know this can be done, but I have no idea how. Does anyone here have some pointers for required hardware, software and configuration?
Save yourself a lot of trouble and get a hardware SIP phone like the Grandstream WP826. I spent years struggling with software phones, most of them suck ass and the good ones aren’t very good.
quick unboxing video
Then make sure to enable voice transport encryption and set SIP transport to TLS (not UDP) and set keepalive timers to something below 3 minutes or so. The encryption settings are not just for security, using TLS for SIP transport has way fewer problems with incoming calls than UDP in 2025 network environments.
There are some firmware issues with the Grandstream WP826 but they are steadily releasing new firmware updates every month or two. If you need absolute bulletproof reliability go for something more expensive, otherwise the WP826 or similar model will likely be good enough (I say that as someone who is easily vexed by shitty software/electronics)