On Thu, 14 May 2026 at 10:52, Chris Bell via GLLUG <[email protected]> wrote: > A Gigaset N300A-IP DECT base has been connected for a couple of years which > can handle one analogue plus three digital VOIP connections at the same time > so that I should still be able to connect when it happens. > Yesterday all the handsets started ringing, repeatedly stopping for about 1 > second before restarting, but I was unable to answer and clear any incoming > call. Picking up one handset and trying to answer did not stop all other > handsets ringing. The ringing stopped shortly after disconnecting the ethernet > cable, and began again very soon after reconnecting. The handsets did stop > ringing after about 2 hours, restarted again after about 30 minutes, continued > for nearly an hour, then stopped again. > I suspect that OpenReach could be testing the FTTC connection prior to > switching off my local telephone exchange, and trying to connect to the VOIP > to analogue adapter in the BT modem provided by Plusnet. > If I replace my modem with the BT modem is it likely to grab any incoming VOIP > SIP connection, or prevent me using another VOIP supplier? I have been testing > an alternative VOIP For a couple of weeks, but have been assured that it is > not the source of the unwanted ringing. > Thanks for any information. > -- > Chris Bell > www.chrisbell.org.uk
Can I ask for some more details on the networking to the Gigaset base? Specifically, what ports you have open for SIP, because I'm aware if you open them to any incoming IP address, there are people who try calling IP addresses on SIP to see if there's a response, some of whom might have malicious intentions. If you're using a VoIP provider for a SIP trunk, you should be able to restrict the ports to only accept incoming traffic from their IP addresses and prevent any other SIP traffic reaching your Gigaset. Regarding the BT modem and grabbing any SIP traffic, I hope/suspect not as my understanding is that providers may well be establishing a separate VLAN connection for SIP traffic, presumably to ensure security for it and thus it wouldn't touch SIP traffic on your public IP address. It also means that SIP traffic on their connection doesn't count in any data usage restrictions on your line. Peter -- GLLUG mailing list [email protected] https://mailman.lug.org.uk/mailman/listinfo/gllug
