Alternatives to OpenVPN for FreePBX on cell phone...
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Secure voice is difficult, overrated, and pretty much always going to be a huge battery drain because encrypting streams of media takes a lot of processor power. I'm with Jared, before you try to solve this problem, really dig into it and see if it makes sense. Almost all people who request VPN for voice traffic do so without actually evaluating it. It's not the import thing that it sounds like. Nice, of course. If it was free and easy, then duh, more security trumps less security. But it's not easy or "free", there is a lot of cost involved (complexity, performance, battery, etc.) So almost always the evaluation says it doesn't really matter, and in over a century of telecommunications history it has never mattered, and should just be skipped.
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I thought I was pretty clear in my OP but I suppose some clarification is in order: This is strictly so that we can connect Android phones to our FreePBX instance. I'm not at all concerned about encrypting / securing voice, just the successful registration of the Zoiper client.
OpenVPN was the only consistent way of getting mobile devices to keep their registration as we can whitelist the VPN ip subnet.
As mentioned, turning on the responsive firewall and using that instead of OpenVPN did not work out well as the IP addresses of the cell phones changes regularly and the firewall would randomly lock users out during re-registration. Perhaps there are some changes that we can make to either the client or FreePBX that will prevent this?
EDIT: When I said "AND SECURE", I was speaking of ensuring that FreePBX itself was kept as secure from "rogue users" as possible while fulfilling our requirement of allowing our mobile devices to register with the service.
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@manxam said in Alternatives to OpenVPN for VoiP on cell phone...:
I thought I was pretty clear in my OP but I suppose some clarification is in order: This is strictly so that we can connect Android phones to our FreePBX instance. I'm not at all concerned about encrypting / securing voice, just the successful registration of the Zoiper client.
OpenVPN was the only consistent way of getting mobile devices to keep their registration as we can whitelist the VPN ip subnet.
Oh, that's odd. We don't see that problem happening. Our mobile devices work very consistently with FreePBX (unless people are at a site that is blocking traffic, then I could see the VPN being used as a work around to a location's own security rules.) But in general, no VPN needed for consistent connections.
But that makes more sense as an issue to overcome.
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Are your Zoiper users primarily on like 4G or LTE connections rather than Wifi? Maybe that's causing it. We do that, but not most of the time.
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This had come up in the past and @bigbear had recommended putting an SBC in front of FreePBX to handle the issue. Although that creates the issue of dealing with that security at a different point, so not a fix completely in and of itself.
https://mangolassi.it/topic/15747/responsive-firewall-and-external-freepbx-users/
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@scottalanmiller : If they're using their mobile phones it means that they're out of the office travelling or on-site at a client and, likely, not connected to WiFi.
When using the responsive firewall, it was during network status changes where there would be a high likelihood that the device would get locked out (e.g. when transitioning WiFi -> LTE)
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I have totally had an issue roaming around and the responsive firewall constantly locked me out as well.
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@Dashrender said in Alternatives to OpenVPN for VoiP on cell phone...:
I have totally had an issue roaming around and the responsive firewall constantly locked me out as well.
Exactly. To which the only "resolution" that worked for us at the time was OpenVPN but it's taking a massive toll on the batteries of the phones
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Okay that makes way more sense.
I have also had issues with the responsive firewall and mobile phones.
But not seemingly as bad as you are.
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Yeah, unfortunately we're seeing at LEAST a 50% chance of being locked out during network connection change or IP address renewal.
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I put ZeroTier on my PBX and on my devices. Never thought about using it for a SIP softphone.
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A few ideas to try. Change openvpn tunnel to not use encryption (save cpu power) but keep authentication. Also extend the time for the keepalive packages (save battery by not having to wake up as often when there is no real traffic over the tunnel).
Might also want to check that the sip client is actually using push notification so it isn't alive all the time when there are no calls. There are also at least two different openvpn clients so there might be a difference in power drain there as well.
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@Pete-S : I've increased the default timeout from 10 120 to 300 900.
We'll see if a) the connection remains stable b) if battery usage decreases.I don't want to disable encryption as FreePBX automatically generates the client config and I don't want to have to custom edit each.
Unless this can be configured strictly on the server side like keepalive?
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@manxam I found this while looking for alternative also. http://dsiprouter.org/
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@Coreytay said in Alternatives to OpenVPN for VoiP on cell phone...:
@manxam I found this while looking for alternative also. http://dsiprouter.org/
Not a lot of info obvious on the page.
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@scottalanmiller : Yeah, I'm not really certain what that software does..
"dSIPRouter can be used to implement different use cases within minutes"Ummm, then this shows a few examples but I'm not certain of the use case for any of these...
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@manxam said in Alternatives to OpenVPN for VoiP on cell phone...:
@Pete-S : I've increased the default timeout from 10 120 to 300 900.
We'll see if a) the connection remains stable b) if battery usage decreases.I don't want to disable encryption as FreePBX automatically generates the client config and I don't want to have to custom edit each.
Unless this can be configured strictly on the server side like keepalive?
Any progress on this?
I don't know how freepbx does the openvpn config files but you should have a setting on what cipher to run. That information ends up in both the client and server config files. To disable encryption you set the cipher to none.
You should probably turn of compression too as voip is already compressed. Just takes more battery power to compress something that is compressed already.
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@Pete-S : within the GUI there are no available options for tailoring OpenVPN unfortunately.
The client config that it generates is :
# Configuration automatically generated via Sysadmin RPM # MODIFICATIONS TO THIS FILE WILL BE OVERWRITTEN. # Generated at: Sun, 13 Jan 2019 03:33:14 +0000 client dev tun proto udp resolv-retry 60 nobind persist-key persist-tun remote-cert-tls server ca sysadmin_ca.crt cert sysadmin_client1.crt key sysadmin_client1.key comp-lzo verb 3 remote x.x.x.x 1194 remote x.x.x.x 1194The server config is :
# Configuration automatically generated via Sysadmin RPM # MODIFICATIONS TO THIS FILE WILL BE OVERWRITTEN. # Generated at: Sun, 13 Jan 2019 03:33:14 +0000 port 1194 proto udp dev tun topology subnet ca sysadmin_ca.crt dh sysadmin_dh.pem crl-verify sysadmin_crl.pem cert sysadmin_server1.crt key sysadmin_server1.key ifconfig-pool-persist ipp.txt #keepalive 10 120 keepalive 300 900 comp-lzo persist-key persist-tun verb 3 client-config-dir ccd ccd-exclusive status sysadmin_server1-status.log 10 status-version 3 script-security 2 server 10.8.0.0 255.255.255.0Note the header stating that this file will be overritten so I'm not certain how "permanent" this will be nor do I see information regarding encryption type (though do see the compression).
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@manxam said in Alternatives to OpenVPN for VoiP on cell phone...:
@scottalanmiller : Yeah, I'm not really certain what that software does..
"dSIPRouter can be used to implement different use cases within minutes"Ummm, then this shows a few examples but I'm not certain of the use case for any of these...
that's where I was. I get that it is a proxy, but I don't get what problem it is solving. It seems to just move the problem, not remove it.
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@Pete-S said in Alternatives to OpenVPN for VoiP on cell phone...:
You should probably turn of compression too as voip is already compressed. Just takes more battery power to compress something that is compressed already.
Good point, watch for double compression.
