trying to provision a t48s phone for stun connection

[herculeon]

the voip server is hosted at our datacenter. the sbc is at the clients office.there is no issue with that. issue now is that the client now purchase a "new" yealink t48s that he wants to use at home.it is running 66.86.0.5 firmware. the phone has been added into the provisoning server and into the phone system. however, when i go to the account tab enter all of the pertinent info, i am still getting a "register failed". not sure what i am missing. i messaged 3cx and they say comtact a service provider which we are, then they say contact the forums, which i am doing now. i have had someone else review everything and even reset it up to make sure i did not miss anything. same issue.register failed. any ideas what else to review?

 

[Plains_JosephW]

the voip server is hosted at our datacenter. the sbc is at the clients office.there is no issue with that. issue now is that the client now purchase a "new" yealink t48s that he wants to use at home.it is running 66.86.0.5 firmware. the phone has been added into the provisoning server and into the phone system. however, when i go to the account tab enter all of the pertinent info, i am still getting a "register failed". not sure what i am missing. i messaged 3cx and they say comtact a service provider which we are, then they say contact the forums, which i am doing now. i have had someone else review everything and even reset it up to make sure i did not miss anything. same issue.register failed. any ideas what else to review?

Hi Herculeon,

What version of 3CX are you currently using?

 

[herculeon]

18.0 (Build 939)

 

[SteveITS]

In hindsight they should have bought a T48U so it could be a router phone. The easiest thing to do is install the SBC software on a PC that stays at the house with the phone, and it will set up via PnP.

 

[herculeon]

unfortunately, the sbc is not really an option.

 

[herculeon]

pardon my ignorance, but why will a t48u be the only option to set up as a stun phone? It is my understanding as well as the understanding of others at my office, that the t48s should work fine as a stun phone, or am I just not understanding the reasoning why? what difference would a router phone make for a stun connection? I do apologize if this comes across as a rudimentary question, but I just do not see it.

 

[JohnS_3CX]

The short version is that STUN is at the mercy of the phone/modem/firewall/provider's ability to allow SIP traffic to pass correctly. Its unpredictable nature means you may get a good experience or it may stop working one day and you will have no idea why.

The T48U has a built in 3CX SBC, which is a piece of software that bypasses common firewall and NAT problems which make STUN so unreliable.

Starting from 3CX V20 STUN will no longer be supported by us, so probably not a good idea to invest in it unless you have the time, knowledge and patience to support it yourself whenever it goes down for seemingly no reason.

 

[herculeon]

ok, makes sense. thanks for the scaled down and informative answer. i can now go back to the customer and let him know.

 

[herculeon]

would you happen to have a list of supported Yealink phones that will work with stun? we are a yealink shop and i need to confirm the list of supported phones for use with stun and without and if they are close to EOL. Well, i can look up the EOL thing, but a supported phone list would be very helpful

 

[SteveITS]

3CX doesn't support STUN though in v16 and 18 it was possible to use. In v20 it gets a bit more difficult one must create a custom template to add a phone using STUN. Much easier to just install the SBC software or use a router phone.

3CX supported phone list: https://www.3cx.com/sip-phones/

Other options for a phone at home are the web client or mobile app.