Correct Router Configuration is a key element in ensuring correct communications between 3CX PhoneSystem and external entities such as external extensions, VoIP Provider services, and other Bridged PBXs. NAT and/or PAT When a network host A sends a request to another network host B, it will be expecting a reply to the request. When both network hosts reside on a Public IP Address, the exchange is direct, and simple enough. If one of the network hosts resides on a Private IP Address, however, things start to be come more complex, because the network environment is a NAT/PAT environment. If network host A is in a NAT/PAT environment, when it sends a request to network host B, it will build its request using the only IP Address it knows – its private IP Address

Configuring Outbound Rules on 3CX PhoneSystem is a very simple affair if you have a single device or service which you deliver calls with – in most cases a single rule will be enough. But the Outbound Rules in 3CX PhoneSystem allows you to create much more complex rules – allowing you to not only select backup routes which come into effect when other routes fail, but also to select a different set of routes, depending on the type of number being dialled. For the sake of this example, we will assume that our PBX: Has a Gateway connected to a 23-channel T1 circuit – best rates for local calls Has a 3CX SkypeGateway connection to reach Skype IDs directly from an extension Has a VoIP Provider account – this channel provides the best rates for international calls, but (in this example) requires the destination number to be presented in full international format, with the international prefix being “00″ Is using 3-digit extensions Has a Bridge connected to another 3CX PhoneSystem (which is also using 3-digit extensions) installed in London Emergency Number Probably the best way to handle the “911″ Emergency Number is to start with it. First we should create an outbound rule to handle such calls: Specifying a prefix which has 3 digits, and restricting the rule to numbers which are 3 digits long, effectively creates a rule for only the number in the prefix field – in this case, “911″. Next, we should also create an extension, with extension number 911, with a single forwarding rule, that forwards ALL calls to external number “911″.

ShareEl release candidate de 3CX Phone System v9 (9.13373) se encuentra disponible para ser descargado desde aquí! El 3CX Assistant ya no necesita ser descargado como un instalador separado, continúe leyendo…
Hemos agregado una nueva funcionalidad …

If you have been asking yourself how to secure 3CX PhoneSystem, read on… 3CX PhoneSystem can receive call requests from the outside to the inside (Inbound Calls), or alternatively from the inside to the outside (Outbound calls). Inbound Calls can only have an internal entity as a destination with 3CX PhoneSystem. One of 2 exceptions is if you have a forwarding rule to send the call to an external number, but this would be an intentional setting on the extension’s forwarding rules.

Introduction This article describes how an extension or a gateway line registers itself with the PBX Server to make itself available for making and receiving calls, and how the PBX Server will register itself with a VoIP Provider to make itself available for making and receiving calls. We trace through these steps by reading the server status log. The Server status log can be accessed by going to the 3CX management console and clicking on the Phone System > Server status log. Scenario 1 – Extension Registration Log message 1 [CM504001] (all logging levels) Ext.100: new contact is registered. Contact(s): [sip:100@172.18.130.27:50386;rinstance=aa14540e328cb432] 3CX Phone System has received a registration request from a device as Ext.100, and has accepted the request because the credentials match. Ext.100 has IP address 172.18.130.27, and will be listening for incoming calls from the PBX Server on port 50386

Although we recommend the use of supported VoIP Providers , in some cases it may be necessary to use an unsupported VoIP Provider. 3rd Party Supported VoIP Providers 3rd Party supported VoIP providers have been tested by the VoIP Provider or by 3CX and at the time of testing they we’re known to work. You can find a list of 3rd party supported VoIP Providers here . Community tested VoIP Providers Community tested VoIP Providers have been reported as working by the community. 3CX has done no formal testing on these VoIP Providers.

Introduction to the 3CX Media Server The 3CX Phone System’s main job is to connect 2 (or more) entities together for transmission of audio between them. However, there are 3 different mechanisms which can be utilized for the delivery of audio streams between 2 endpoints: Bypass Mode (Direct) Proxy Mode (Pass-Through) Transcoding Mode (Bound to Media Server) Audio streams are delivered by the 3CX Media Server. The inbuilt 3CX Media Server can recognize whether the call is an internal call an external call by making a calculation based on the comparison of the 3CX Phone System Local IP address and Subnet mask, it’s interfaces and those of the settings set on the phone or party. This is one of the 3CX Main core services. By Pass – Direct Mode In this mode, media server does not take any part in the RTP stream delivery between two sip entities. Both entities will negotiate with the PBX to send the RTP stream directly to each other.

Note 1: The results generated from these tests should remain valid while the VoIP Provider keeps your account settings static. If your VoIP Provider account is reconfigured, it may be necessary to redo these tests. Note 2: The supported configuration for interoperability with VoIP Providers is for the PBX to be behind a WAN-to-LAN device, with Port Forwarding implemented correctly. Pre-Requisites Before you start your testing, you should have some items in place to ensure: You can complete the tests in one run without interruptions You complete all the tests to ensure correct interoperability List of pre-requisites: You must have at least one (ideally two) external telephone lines available for testing – note that: This must be in ADDITION to your lines connected to 3CX Phone System, and indeed should NOT be connected to 3CX PhoneSystem or any other PBX This line must NOT have its CallerID withheld. When you make a call from this line to some other phone, the destination phone MUST be able to see the number of the line originating the call. Without this, the tests for outbound CallerID will be invalid

If you are using a VOIP provider , then you will have to configure your firewall correctly in order to get reliable results. Your firewall must support STATIC PORT MAPPING. 3CX Phone System needs the following ports mapped on the router or firewall to operate properly: Port 5060 (TCP and UDP) – Used for SIP protocol transmission – must be a static mapping, no port translation Port 5090 (TCP) – Used for 3CX tunnel (if tunnel is enabled) Port 9000-9015 (UDP) – Used for RTP protocol for incoming and outgoing calls For business grade results you will also need a static/dedicated IP. Note that many cheap routers do not correctly port forward, and this will lead to problems when making calls