heres a new solution to try, not sure if it will work but here's the idea:-

Create 2 new extensions, one on each of the IPPBX's and configure how you want them to handle calls, i.e forward to a group or other extension.

Then in the IPPBX line settings on each of the IPPBX's, create a new SIP trunk, use details for the new extensions you have just created on both IPPBX's.

Try dialing the remote extensions created (or try the trunk number) and see if the calls terminate.

Post back and let me know if this works as i haven't got the time at the moment to try this.

Although not an officially recommended method, you should be able to set up a remote extension and let the remote PBX log into it as one of its own trunks, then have a digitmap rule use that trunk for the remote extensions. Each PBX should have a unique extension range e.g. 8xxx on one and 7xxx on the other.

That's cool.

For the record, it was just an idea (purely experimental solution) to bridge the gap in the ippbx2820 feature set not supporting direct links to other ippbx2820's and was never meant as an 'official' solution to the problem.

If it's a workable step around then great! Nothing ventured, nothing gained as they say.

Has anyone tried implementing the idea yet and do they have any feedback to post back?

Unique extension ranges noted! Thanks for the input admin

I have tried this as I thought this would be the way to do it initially. The problem is that even with the digit map it dials however the remote end just stops it doesn't go any further or even attempt to dial.

In the call log you see it try to use the trunk bit nothing else.

The trunks show as registered I just cant seem to make calls this way. I might clear the current entries and give it one last go as I cant see why this shouldn't work.

Just to add to my previous post, I do now have this working. The annoying thing is yet again the firmware is at fault. The newest 3.5.5.1 software (as well as crashing randomly) wont allow the trunk scenario to work. I reverted back to the 3.5.5 and all now works as expected.

I have to admit Im getting rather fed up with the whole one step forward two steps back development path on the IPPBX. It really isnt what Draytek make it sound like. Anyway in case anyone does find they have a need for a similar setup make sure you are on 3.5.5 and all will work fine.

the thing that really gets me boardsurfer-1 is these firmwares are released as being tested from betas. makes you wonder who is the one who is actually testing them and clearing them for final release!

glad you got it sorted in the end!