little help plz

[mcnick50]

i received the following email from our provider OTE in Greece..

Dear customer
In the context of the continuous improvement of the telecommunications network in our country, we inform you that in the period from November 23-27, the OTE Group will proceed with the upgrade of the infrastructure in your area, with the aim of providing high quality services.
According to the specifications of our network, changes will have to be made in the configuration of your call center, as it has been detected that the "SIP Trunking" between the CPE / PBX and the OTE network is done statically and not through DNS resolving for "ims.otenet .gr ".
If DNS resolving is already used on PBX for "SIP Trunking" or you do not have a call center, then ignore the instructions below.
- You must use DNS (212.205.212.205, 195.170.0.1, 195.170.2.2) for Registration / Proxy / Outbound Proxy.
(Specification is for the PBX to support DNS SRV).
- The field "Contact:" during the Registration is of the form E.164number@IP-of-PBX (eg Contact: [email protected])
- SIP Options: Disable SIP Options to the Network.
- Codecs: Default / 1st priority codec G.711 (PCMA).
- In case the PBX has REGISTERED on the Network and there is no call (either Outbound or Inbound), please proceed to RESET of SIP-Trunk on the PBX side
For the smooth operation of your call center the changes should be made as soon as possible, ideally until 22/11/2020


what i have to change didn't understand

 

[JohnS_3CX]

If you have it and it is already working, then the only thing you will probably have to change is this:


And in the options tab keep it like this:


For the rest, you will have to contact your provider. As a matter of fact since this is not a supported provider, I would recommend you call them and get clarifications over the phone if you want to be sure.