• Releases

    3CX Product Releases

  • VoIP How To

    Technical tips to run your VoIP PBX more efficiently

  • Events

    3CX Trainings and Webinars around the world

  • Docs & FAQs

    3CX Documentation how to and FAQ

  • Phone configuration

    3CX, Aastra, Cisco, Yealink, Grandstream, Polycom configs

stun protocol

Troubleshooting a Direct Remote Extension

February 10, 2012 - 8:03 pm | 7 Comments

This step by step guide will help you troubleshoot a direct remote extension setup at home or at a remote office. Direct remote extensions can work but correct functionality cannot be guaranteed as there are many factors at play (such as: Network Topology, Router configuration, Firewall settings, etc.) and you may not have control over all the devices involved to make the proper changes necessary for a direct remote extension

......Read More »

Configuring External Extensions with 3CX Phone System

January 15, 2012 - 10:30 am | 10 Comments

Connecting an External Extension to 3CX PhoneSystem is often requested, and can be extremely useful for linking small remote offices and home workers. Here we get a shot at using other phones as External Extensions. Note: If you are looking for instructions to connect a SIP Hardphone using the 3CX Tunnel Protocol via the 3CX SIP Proxy Manager, please view this guide. Using a SIP Hardphone as a Direct External Extension

......Read More »

Router Configuration for 3CX PhoneSystem

July 23, 2010 - 5:17 pm | 3 Comments

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.

......Read More »

Firewall Configuration Overview for 3CX PhoneSystem

March 29, 2010 - 2:57 pm | 0 Comments

In order for 3CX Phone System to communicate successfully with VoIP providers and Remote Extensions, your firewall/router device must be configured for SIP operation. To maximize your chances of success, make sure you choose a device that does not implement a SIP Helper or SIP ALG, or which can be configured to be disabled.

......Read More »

The STUN Protocol Details

September 14, 2009 - 7:56 pm | 0 Comments

As seen in a previous article, STUN protocol plays an important role in VoIP implementations: to discover the presence of NAT and to learn and use the bindings allocate to the client by the NAT. In this article, we will look into details of the STUN protocol itself. The STUN Protocol STUN is a client-server protocol. A STUN client (typically embedded in VoIP software, such as an IP PBX or

......Read More »

How and when can I switch off STUN Resolution?

March 1, 2009 - 3:48 pm | 0 Comments

How and when can I switch off STUN Resolution STUN resolution is necessary for the PBX to understand what it’s public IP Address is, and what port mappings are in effect for Media (to attempt NAT traversal when port forwarding is not implemented). STUN resolution may be disabled when: No External entities are in use (no bridges, voip providers, extensions) AND/OR Static Port Forwarding is in place for reliable media

......Read More »

3CX PHONE SYSTEM

PRODUCTS

TECHNICAL INFORMATION

PRODUCT DOCUMENTATION

All Rights Reserved © 2012, 3CX

Switch to our mobile site