Alternatives to OpenVPN for FreePBX on cell phone...

Reid Cooper

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/

manxam

@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)

Dashrender

I have totally had an issue roaming around and the responsive firewall constantly locked me out as well.

manxam

@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

JaredBusch

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.

manxam

Yeah, unfortunately we're seeing at LEAST a 50% chance of being locked out during network connection change or IP address renewal.

JaredBusch

I put ZeroTier on my PBX and on my devices. Never thought about using it for a SIP softphone.

1337

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.

manxam

@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?

Coreytay

@manxam I found this while looking for alternative also. http://dsiprouter.org/

scottalanmiller

@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.

manxam

@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...

1337

@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.

manxam

@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 1194

The 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 10.8.0.0 255.255.255.0

Note 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).

scottalanmiller

@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.

scottalanmiller

@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.

Dashrender

@scottalanmiller said in Alternatives to OpenVPN for VoiP on cell phone...:

@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.

Well if the proxy can solve the firewall lockout issue on mobile devices and changing IPs... but then, if the Proxy can solve it - why can't the firewall in FreePBX?

manxam

@Dashrender : FreePBX uses a really stupid implementation IMO.
The responsive firewall bans a user if they have connected but not registered in X time. This is sane.
But fail2ban remains on with it and bans the IP before the responsive firewall is given time to check for registration.

scottalanmiller

@Dashrender said in Alternatives to OpenVPN for VoiP on cell phone...:

@scottalanmiller said in Alternatives to OpenVPN for VoiP on cell phone...:

@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.

Well if the proxy can solve the firewall lockout issue on mobile devices and changing IPs... but then, if the Proxy can solve it - why can't the firewall in FreePBX?

But how can it? Sounds like all it does is disable the firewall, right? You can do that by just... disabling it! Seems pretty silly to implement an entirely separate system just to work around a firewall that you can just turn off with a button.

Dashrender

@scottalanmiller said in Alternatives to OpenVPN for VoiP on cell phone...:

@Dashrender said in Alternatives to OpenVPN for VoiP on cell phone...:

@scottalanmiller said in Alternatives to OpenVPN for VoiP on cell phone...:

@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.

Well if the proxy can solve the firewall lockout issue on mobile devices and changing IPs... but then, if the Proxy can solve it - why can't the firewall in FreePBX?

But how can it? Sounds like all it does is disable the firewall, right? You can do that by just... disabling it! Seems pretty silly to implement an entirely separate system just to work around a firewall that you can just turn off with a button.

eh? I have no idea how it actually works.

But assuming it takes more false hits to get something blocked in this proxy's firewall than it does in FreePBX's firewall, then that would solve the problem.

But then the question is can FreePBX's firewall be changed to make it wait say 30 second from connection to logon before blocking it (this is just a guess, I don't know why it's actually failing/blocking the remote phones other than of course it's coming from a new IP).