In reply to a post by Pheasant:

All the native Android/iOS push notifications are done by Groundwire SIPIS servers in the background. App doesn't need to be running at all.

So effectively the call registration is done like so:

PSTN/Whatever ------>Sipgate---->Groundwire SIPIS------>your smart phone
..........................................----->N300A------------------>your DECT handsets

The SIPIS servers keeps the registration alive with Sipgate servers, for calls to your smartphone.

Because there are effectively 2 simultaneous SIP registrations (one for Groundwire and one for Gigaset N300) at Sipgate then inbound calls are alerted simultaneously on both streams.

Got you. Thanks Pheasant.

Any idea which of the iOS apps it is?
There's:
https://apps.apple.com/gb/app/acrobits-softphone/id3...

And...
https://apps.apple.com/gb/app/acrobits-groundwire/id...

I assume the second one?

Groundwire just has conferencing and call transfer features, which Softphone does not. That's the only difference, both support the same core functionality / push features etc. Its a 2 quid one off uplift for Groundwire.

In reply to a post by Pheasant:

Groundwire just has conferencing and call transfer features, which Softphone does not. That's the only difference, both support the same core functionality / push features etc. Its a 2 quid one off uplift for Groundwire.

Great advice as ever Pheasant, thank you.
I've gone for the cheaper option, simply because I can never see us using conferencing & call transfer on our residential landline service.

As you stated, it works a treat (i.e. app not running in the background but it still rings when the number is dialled).

Acrobits was a breath of fresh air after years of frankly [censored] VoIP soft phone apps.

Glad you're pleased Miles.

In reply to a post by Pheasant:

Acrobits was a breath of fresh air after years of frankly [censored] VoIP soft phone apps.

Was following this thread and have just bought it to move my SIP number to the mobile from my Cisco ATA. Very impressed - thank you!

You’re welcome. It’s a really clever supporting infrastructure they’ve put together. There was a diagram floating around somewhere, but I can’t find it now.

There’s lots of things I really like about it like the ability to run multiple simultaneously functioning SIP registrations. I’m super impressed with it.