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VOIP over 4G

Level 1: Joiner
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Hi - I have an unlimited data SIM that provides braodband connection to the home via a router and then wifi.  The old landline connection was useless (meant to be FTTC but no better than ADSL) and the 4G connection is giving us on average 30mbps down and 12-15 up which makes a huge difference.  My issue comes from the fact that I transferred our old landline phone number to a virtual host (Virtual Landline) which then uses a VOIP adapter to connect the exisiting phone extensions in the house.  This works but is intermittent - the SIP connection to the host is through a VPN tunnel but fails after a few hours of rebooting.  Ideally a fixed IP address would be used but not possible with the O2 CGNAT/IP addressing, hence the use of the VPN.  Is it O2 that will be knocking out the VPN connection for some reason as each time it happens, the VOIP adapter needs to be manually rebooted which isn't a long-term solution?  If so is it possible to get O2 to either give the SIM card a fixed external IP address or allow a permanent VPN connection?  Thanks for any help!

Message 1 of 5

Level 94: Supreme
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Sounds like something @Chris_K might be able to help with?

I have no affiliation whatsoever with O2 or any subsidiary companies. Comments posted are entirely of my own opinion. This is not Customer Service so we are unable to help with account specific issues.

Currently using:
OnePlus 6 (O2 & Sfr), Z3 Tablet (Three UK), iPhone 8+ (EE)
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O2 Social Media Team
O2 Social Media Team
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Hey there. Sounds like a pretty complicated setup that I don't pretend to quite fully understand in my head - but if it's not the VPN service itself that's causing the disconnects, then it will more than likely be on the network side due to the nature of how mobile networks work - sessions will shift about, close and re-open - and for probably 99.9% of customers who use internet, netflix, spotify etc, they'll never notice any of this happening.

For consumer SIM's, we don't offer fixed IP addressing I'm afraid - for that, you would need to look at Business & Enterprise solutions, or potentially IoT/M2M resellers.

Hi. I'm from the Social Media Team.

Message 3 of 5

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Thanks @Chris_K - makes sense - just a shame that the VOIP adapter doesn't automatically the VPN connection to Virtual Landline when it gets knocked out/changes temporarily.  I can't think of an immediate solution bar moving across to a business contract (we have business connections already with O2) - would this be possible do you think to be able to get a fixed external IP address?  Thanks  David

Message 4 of 5

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You will find that O2 does not choose to support VOIP services over 4G. My VOIP service App works perfectly on my wife’s phone on Vodafone but drops after 30 secs on every call on my O2 phone. I am changing back to Vodafone. 

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