Bit of a strange one (well to me at least!)
I am using a Gigaset N300A IP with a VOIP line provided by AAISP. This is used purely to receive incoming calls (is being used as a test prior to the migration of my existing PlusNet landline when I move from their FTTC (80/20) to a fully FTTP connection (Zen 100/20). As an aside will be running both FTTC & FTTP simultaneously with intention that former will be automatically ceased when I port the associated number to AAISP
As a gateway device I am operating a pfsense firewall and have succesfully configured it to talk to AAISP. Everything appeared to work just fine (in fact the line quality if anything appeared better than my existing copper land line).
A number of friends have called me using various providers, all with absolutely no problem, that is until a friend whose telephone provider is Talk Talk rang (note NOT VOIP)
Bizarrley to the absolute second every 15 minutes the line drops. He can immediately rediall and it rings at my end and we carry on where we left off. BT/PlusNet and mobile calls appear to be unaffected, only this TT line.
I am minded to think that if is probably some form of over aggressive line monitoring at the TT end assuming that the line has dropped (or the connected call is not showing any data passing).
Given that it only happens with TT I don't think this is a malfunctioning SIP session timer, but I was wondering if anyone else had come across any issues with TT ?