Sending this to SEG soon:-

Setup:- 2820vn(1) sn 097001584035 2820vn(2) sn 083001321799 (problem device) 2910vg

Problem description & tests so far :-

sip to sip on any 2820vn to 2820vn works faultless,

sip to sip 2820vn(2) to 2910vg or vice versa results in one way audio, voip to voip via draytel supplied landline number works fine on any device to device calls..

Sip to sip 2820vn(1) to any of the routers works fine.

2820vn’s physical locations swapped, fault followed 2820vn(2)

2820vn configs swapped after factory resets, fault followed 2820vn(2)

2820vn(2) re configured from factory reset from scratch, just configured enough for internet access VOIP account and dial plan to contact other 2820vn & 2910vg, Fault remained with 2820vn (2).

Possible issue could be between 2910vg & 2820vn(2) hardware revision?? the problematic 2820vn used to work on previous firmwares but at this stage not sure how far back i'd have to go!!!

Both 2820vn’s using firmware 3.3.5.1_232201

2910vg using firmware 3.2.5.1 problem existed before this was last upgraded.

2820vn configs swapped after factory resets, fault followed 2820vn(2)

Surprising, but difficult to ignore the facts. Up to that point it seemed to me that it would be a cfg issue. Are you 100% sure the only change was the routers? Sip accounts weren't swapped also?

Took the routers physically swapped their locations, this was one of the first moves, the sip accounts moved with the routers initially without config changes to verify it wasn't a LAN issue, also I think I said anyway take config from working router, load it into problem router, the problem remains on 1 router only ( obviously only running one at a time) with an Internet connection

fault i found has been verified by draytek, the router was rma'd to them, confirmed the fault i was seeing, they replaced it, no issues now, and what a great service i got from them.