3.9 VoIP

Voice over IP network (VoIP) enables you to use your broadband Internet connection to make toll quality voice calls over the Internet.

There are many different call signaling protocols, methods by which VoIP devices can talk to each other. The most popular protocols are SIP, MGCP, Megaco and H.323. These protocols are not all compatible with each other (except via a soft-switch server).

The Vigor V models support the SIP protocol as this is an ideal and convenient deployment for the ITSP (Internet Telephony Service Provider) and softphone and is widely supported. SIP is an end-to-end, signaling protocol that establishes user presence and mobility in VoIP structure. Every one who wants to talk using his/her SIP Uniform Resource Identifier, “SIP Address”. The standard format of SIP URI is

sip: user:password @ host: port

Some fields may be optional in different use. In general, "host” refers to a domain. The “userinfo” includes the user field, the password field and the @ sign following them. This is very similar to a URL so some may call it “SIP URL”. SIP supports peer-to-peer direct calling and also calling via a SIP proxy server (a role similar to the gatekeeper in H.323 networks), while the MGCP protocol uses client-server architecture, the calling scenario being very similar to the current PSTN network.

After a call is setup, the voice streams transmit via RTP (Real-Time Transport Protocol). Different codecs (methods to compress and encode the voice) can be embedded into RTP packets. Vigor V models provide various codecs, including G.711 A/µ-law, G.723, G.726 and G.729 A & B. Each codec uses a different bandwidth and hence provides different levels of voice quality. The more bandwidth a codec uses the better the voice quality, however the codec used must be appropriate for your Internet bandwidth.

Usually there will be two types of calling scenario, as illustrated below:

zCalling via SIP Servers

First, the Vigor V models of yours will have to register to a SIP Registrar by sending registration messages to validate. Then, both parties’ SIP proxies will forward the sequence of messages to caller to establish the session.

If you both register to the same SIP Registrar, then it will be illustrated as below:

The major benefit of this mode is that you don’t have to memorize your friend’s IP address, which might change very frequently if it’s dynamic. Instead of that, you will

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Vigor2800 Series User’s Guide

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Draytek 2800 Series manual VoIP, Sip userpassword @ host port, Calling via SIP Servers

2800 Series specifications

The Draytek 2800 series is a robust solution in the realm of networking, catering primarily to small and medium-sized enterprises (SMEs). This series provides essential features for those looking to establish reliable and secure connectivity. With its advanced technology, it positions itself as an excellent choice for businesses needing to manage their network capabilities efficiently.

One of the standout features of the Draytek 2800 series is its support for various WAN connections. Businesses can opt for ADSL, ADSL2+, or Ethernet connections, allowing them flexibility depending on their internet service capabilities. This versatility ensures that users can select the most appropriate setup based on the local infrastructure.

In terms of security, the Draytek 2800 series is equipped with robust firewalls, including stateful packet inspection and DoS protection. This ensures that the network remains protected from potential threats. Additionally, it offers VPN capabilities, enabling secure remote access for employees working from different locations. The support for multiple VPN protocols, such as PPTP and L2TP, allows for secure and versatile connections.

The series also features an integrated, 4-port Ethernet switch, simplifying the task of connecting multiple devices within a local area network. This encourages seamless communication and data sharing among connected devices. Furthermore, the Draytek 2800 series supports Quality of Service (QoS) capabilities, which allows businesses to prioritize bandwidth for critical applications, ensuring that high-demand services such as VoIP and video conferencing operate smoothly without interruptions.

Another characteristic is its web-based management interface, which simplifies network administration. IT professionals can easily configure and monitor the router settings without needing extensive technical expertise. The series also supports dynamic DNS, which is crucial for businesses that require consistent access to their networks through domain names rather than constantly changing IP addresses.

Additionally, the Draytek 2800 series is designed for scalability, allowing businesses to expand their network as needed without significant overhauls. This flexibility ensures that the system can grow alongside the business.

In summary, the Draytek 2800 series combines advanced features, reliable performance, and enhanced security, making it a preferred choice for SMEs looking to build a solid networking foundation. Its flexibility, security features, and user-friendly management tools provide a comprehensive networking solution that meets the needs of modern businesses.