How an IP PBX / VOIP Phone System Works

A VoIP Phone System / IP PBX system consists of one or more SIP phones / VoIP phones, an IP PBX server and optionally includes a VoIP Gateway. The IP PBX server is similar to a proxy server: SIP clients, being either soft phones or hardware based phones, register with the IP PBX server, and when they wish to make a call they ask the IP PBX to establish the connection. The IP PBX has a directory of all phones/users and their corresponding SIP address and thus is able to connect an internal call or route an external call via either a VoIP gateway or a VoIP service provider to the desired destination.

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At the center we have, the IP PBX. Starting from the bottom, we see the Corporate Network. This is the company’s local network. Through that network, Computers running SIP clients, and IP Phones connect directly to the PBX. On the left, we see the company’s router/firewall connected to the internet. From there it can connect to remote extensions in the form of computers running the softphones, remote IP Phones, mobile devices running the Android and iOS apps, and Bridged PBX’s. Using a VoIP provider we can connect to the PSTN network. To the right a VoIP Gateway connects the PBX directly to the PSTN network.

All-IP Migration Solution

It’s no secret that PSTN and ISDN is coming to an end. We provides a reliable and cost-effective IP-capable portfolio and empowers businesses with a future-proof telecommunication system.

By driving forward to All-IP future, businesses can experience quality communications, benefit from decreased communication costs and simplify operations by using a single technology for telephony and data. We provides an easy way for businesses to move to All-IP smoothly.

Complete IP-based Product Portfolio

We provides a complete All-IP capable portfolio that supports any network infrastructure. For businesses that wishes to keep using the existing Analog PBX or ISDN PBX, they will find VoIP Gateways suitable for their migration; and for companies ready to take advantage of unified IP communications, VoIP PBX and Cloud PBX will meet their various communication needs easily and seamlessly.

Increase mobility and productivity

Linkus Mobile Client, an application integrating IOS and Android mobile phones with VoIP PBX, can help employees receive and reach calls whenever and wherever they are and with any devices that is connected to the PBX system, which could highly improve work efficiency. Moreover, VoIP PBX system boasts rich robust features like call statistics, IVR, queues, SIP forking, call recording, conferencing and so on, making communication easier.

Add new users and sites easily

Featuring flexible modular design and simple deployment, VoIP PBX can grow with your business and support up to 500 users and 120 concurrent calls. Besides, you can replace legacy system at remaining sites once centralized IP connectivity is available and connect all teleworkers and mobile workers with the IP system.

Excellent voice quality


By switching to IP telephony, you can improve and secure the voice quality with Codec and Quality of Service (QoS). Thanks to the high-definition voice technology, you can now enjoy calls without noise and reverb.

Reduce communication costs

All-IP based system greatly reduces communication fees by guaranteeing free internal calls and low-cost external calls through SIP trunk, so you don’t need to worry about the high phone bills anymore. Moreover, carriers will offer cheaper solutions to attract more customers at this time.

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