do i have to use a sbc if i deploy 3cx in the cloud

[Shawn]

i'm experimenting and just deployed a trial of 16 using pbx express on google cloud. the pbx is running and i connected to it with an android mobile client which goes through the 3cx tunnel. i'm trying to connect an ip phone to the pbx but am having a hard time figuring out the fanvil x4 interface on how to provision it outside the LAN.

now i'm wondering if i should use a local sbc which would make ip phone provisioning much easier since i'm assuming that the phones would show up as new phones in the management portal of the pbx even if new phones were connected to the sbc.

can someone let me know why i would want to use a sbc instead of connecting a bunch of ip phones directly to the pbx in the cloud. i understand the simplicity of the tunnel and not having to mess with firewalls and such but, firewall and simplicity set aside, what other reasons are there to use a sbc instead of direct connect?

by the way, does pbx express deploy the pbx in a linux environment? it never gave me any choices as to what platform i wanted.

thanks

 

[craigreilly]

My server is in the office - but I do have 4 phones in a remote office on the other side of the country using STUN. I have not had any issues - and the firewall is not mine at that location.
Just have to increase my ports manually for each setup.
Why not use an SBC - especially for the price of a Pi ~$50 or so.

 

[cobaltit]

i'm trying to connect an ip phone to the pbx but am having a hard time figuring out the fanvil x4 interface on how to provision it outside the LAN.

Then it would appear you are not following the guide:

https://www.3cx.com/sip-phones/fanvil-x3-x5/

You should be picking STUN and rebooting the phone, no accessing the phone web interface needed.

 

[Cascada]

You don't need to use SBC. I have 1 deployment with 5 phones all of them STUN. However, I found out for phone deployment and firewall load/configuration the SBC makes your life easier. If you decide to use STUN remember to move up the ports for each device. Also, uncheck the DISALLOW OUTSIDE LAN registration and finally, you need to use PBX to provide audio.

 

[Shawn]

can you provide some more detail on what you mean by "move up the ports for each device". are those the ports specified in the ip phone section of the phone provisioning tab. do i manually specify a separate sip port for each phone? do i specify a different rtp port range for each phone?

also, does pbx express install 3cx on debian?

thank you for all the pointers and expertiese. i provisioned one phone and it's working well. i'll probably take the sbc route as recommended.

 

[leejor]

This is a bit dated (deals with older versions of 3CX), but scroll down to the last section dealing with STUN.
https://www.3cx.com/docs/manual/configuring-ip-phones/#h.ul2fzupi6t22/

Also...

https://www.3cx.com/3cxacademy/videos/intermediate/configuring-remote-extensions/

 

[craigreilly]

This need to be incremented.
I use odd numbers only for Local SIP Port... I do not remember if that is in instructions or I just made it up.

 

[leejor]

I use odd numbers only for Local SIP Port... I do not remember if that is in instructions or I just made it up.

As long as each is unique, I don't think it really makes a difference if they are sequencial, or count up odd, or even.

 

[BrenttG]

in 3cx 15.5 sp6 and higher, they increment the RTP ports by 20, so a given extension would have 14000-14019