Strange, non-deterministic behaviour calling certain numbers ... showstopper

[saruman]

My wife works for a large company that has their own internal phone system with direct inward dialling. So I can dial my wife directly from outside.

This works correctly with my landline, my cell phone and via the Viopo softphone credentials, but when I use my Viopo phones connected via the GrandStream HT502 I connect properly only about 10% of the time.

If the phone rings (sometimes it does not), from her perspective it disconnects the call immediately she picks up. From my perspective, I hear no ring tone and (maybe) a click indicating connection and then nothing.

All other calls we have made so far seem to work OK, but if we cannot get this fixed it is a show-stopper.

My hardware setup is:-

bridged cable modem with static IP <--> linksys router running DD-WRT<--> HT502 with static ip address in bridged mode

[ai2000]

VOIPO support will ask for the numbers and add them to their routing. Seems to fix the problem.

Very manual and frustrating as my wife is at the end of her rope dealing with not being able to make calls at times due to this 'feature' of VOIPO service.