VoIP (Voice over Internet Protocol) is starting to be big business. With VoIP, businesses and home users can bypass the telephone company and make toll calls virtually anywhere in the world for a fraction of the cost of traditional calling. And not only do people save money with VoIP, but it also is a driver to encourage people to upgrade their business or home network and internet connections.

In a nutshell, VoIP enables people to speak to each other using the internet instead of the Public Switched Telephone System (PSTN). The conversations are carried over the exact same copper lines that support PSTN voice conversations. It’s just that you skip the telephone company. VoIP then, is an inexpensive alternative to traditional PSTN telephony.

VoIP is the next step in the evolution of internet-based applications. It follows in the footsteps of email, web browsing, gaming and file sharing. As the internet infrastructure becomes more robust and feature-rich in New Zealand – we’re already seeing a huge increase in broadband and wireless capabilities – VoIP will become much more prevalent.

Benefits of VoIP
The main benefit right now for VoIP is price. Home and SME users can save 50% or more on toll calls. Larger organisations can save even more. Implementation costs are, for basic VoIP services, extremely reasonable. Customers pay a fixed fee per month, anywhere from $10 per month on up, depending on services, plus a cost-per-call that is significantly less than PSTN-based toll calls.

While the key driver right now is price, a more important benefit of VoIP, especially in the SME market, is the integration of voice and data communications within the same program. Known as unified messaging, this eliminates the need to retrieve and send messages using separate systems. Users may organise their phone directories directly from their PCs. Unified messaging applications also enable users to use their multifunction mobile devices to manage all their communications.

How it works
When we speak of VoIP, we are referring to Voice over IP/Broadband as opposed to simply Voice over IP. VoIP in its narrowest sense, could be simply voice communications over a local area network. For the vast majority of potential customers however, VoIP refers to Voice over the public internet, typically broadband.

VoIP works like email. Data sent over TCP/IP (transmission control protocol/internet protocol) networks consist of packets, with a header for controlling communication and information for transporting data. VoIP digitises voice into data packets, sends them through the network and converts them back to voice when arriving at the destination.

The internet protocol, or IP, does not provide a mechanism to ensure data packets are delivered in sequential order nor does it guarantee bandwidth. Specifically, the protocol will not in itself, differentiate network traffic based on the type of flow, nor does it ensure that the proper amount of bandwidth and prioritisation level are defined for a particular type of application. Because IP does not inherently support the preferential treatment of data traffic, it requires additional capabilities in order to support VoIP functionality. These capabilities, collectively referred to as ‘Quality of Service’ or QoS, are one of the ‘value adds’ provided by VoIP service providers.

IP-based networks are actually very simple. QoS and other enhanced features – encryption, packet-shaping, traffic management, etc – all happen at either end of the connection. This has allowed the internet to scale extremely well. As more hosts are connected, network service demands eventually exceed capacity, but service is not denied. Instead it degrades gracefully. This degradation does not adversely affect applications such as email, file transfer and browsing. However, VoIP, by its very nature, cannot adapt to inconsistent service levels.

SIP
Which brings us to SIP, or session initiation protocol. SIP is the underlying standard employed by VoIP service providers that ensures QoS, clear sound quality, privacy and advanced phone and multi-media capabilities. SIP is an application-layer control protocol that can establish, modify, and terminate multimedia sessions including VoIP. SIP can also invite participants to already existing sessions, such as multicast conferences. Media can be added to (and removed from) an existing session. SIP transparently supports name mapping and redirection services, which supports personal mobility - users can maintain a single externally visible identifier, regardless of their network location.

SIP resides in Layer 7 (the Application Layer). It is independent of the lower-layer protocols, so it does not depend on the type of transport used or even on the type of session being established. SIP also exemplifies the modern trend to develop protocols in the higher OSI layers (for example, XML switching, also in Layer 7) to handle network, service and application convergence as telecommunications become more sophisticated and software oriented.

The VoIP Service Provider enables SIP via the use of proxy servers which are a crucial part of a SIP infrastructure. The SIP proxy servers play a role similar to routing in an IP infrastructure, as their job is to ensure that requests are routed to the appropriate entity, identified by a SIP Uniform Resource Identifier (URI). To do this, proxy servers interpret requests and may rewrite parts of the request message before forwarding it. Typical tasks include handling registrations and invitations to sessions from user agents and applying call policies governing whether a given user can make particular calls.

What are the components of VoIP?
At the very least, VoIP users need a broadband internet connection and one of the following:

• VoIP-enabled handset that connects directly to the broadband router/modem;
• VoIP-enabled adapter that connects the regular telephone handset to the broadband router/modem.

Typically users can make a VoIP call to another VoIP-enabled PC or VoIP-enabled telephone directly over the internet. However, if they want to be able to make VoIP call to a regular telephone or get advanced services such as call waiting, caller ID, forwarding or a local phone number, they have to have an account with a VoIP Service Provider.

The Internet Connection & Modem / Router
VoIP requires broadband, more correctly known as Asynchronous Digital Subscriber Line (ADSL), which provides high-speed ‘always on’ internet access. Many vendors now offer ADSL modem/routers with two phone ports so that your clients can connect their regular telephone directly to the internet as well as four LAN ports and wireless access capabilities.

There are also more advanced modem/router solutions on the market that offer IP PBX capabilities, such as multi-line connectivity, messaging, call holding and background music. These are ideal for small to medium enterprises and typically require the specialist services of a qualified VoIP technician to install and configure. JV Systems are qualified to install and setup this for your home and/or business.

VoIP Phone Adapter
A VoIP Phone Adapter allows your clients to connect their regular telephone to the internet via the modem/router. Users simply plug their PSTN phone into the adapter and plug the adapter into the modem/router. They don’t even need a PC.

In order to activate the VoIP adapter, customers need to set up an account with a compatible VoIP service provider. They simply dial the number provided with the adapter and they activate your account. The service provider will assign them a new local telephone number and offer a selection of services, depending on the provider they choose. JV Systems has partnerships with a number of major VoIP service providers and can ensure the best deal for your requirements.

Once their account is activated, they can use their existing phone in the same manner as they do now. The only difference is, that their telecommunications bill at the end of the month will be much lower.

VoIP Phone
The VoIP phone is easier still. All users have to do is plug it directly into their modem/router, dial up the number of a compatible VoIP service provider to set up the account and then start calling. Depending on the model and VoIP package they select, they can have a basic service or an account with advanced services. Customers will receive a new local phone number for their VoIP telephone. The VoIP phone works just like a regular phone, with the exception that it is much less expensive to operate.

What is Skype?
Skype (rhymes with ripe) is a peer-to-peer VoIP network that, in its most basic form, allows internet-enabled PC users to talk to one another for free. It was the first widely-adopted VoIP network. Skype users can speak to other Skype users, call traditional telephone numbers for a fee (SkypeOut), receive calls from traditional phones (SkypeIn) and receive voicemail messages.

Many vendors are now offering Skype telephones that have the Skype software pre-installed (see below for models supplied by JV Systems). It is the exact same concept as generic VoIP – in effect Skype is the VoIP service provider. Some Skype phones connect to your PC, others connect directly to the modem/router and some are wi-fi enabled, which means you can use them over a wireless internet connection, either at home or in a public ‘hotspot’.

The VoIP Service Providers
There is a growing number of VoIP service providers in NZ, the key advantage of a VoIP service provider is that they offer a higher level of support for the end user, typically by supporting the SIP standard (see above).

Here is a quick overview of four key players that JV Systems supports.

WorldXchange / Xnet Virtual Fone Xchange (VFX): www.xnet.co.nz/vfx/index.shtml
VXF is a low-cost, feature-rich, easy-to-use IP telephone service that gives anyone with a DSL connection access to the WorldxChange Voice VoIP network. VXF is optimised to work with Linksys VoIP hardware such as the WAG54GP2v2 router/gateway. WorldXchange are JV Systems preferred VoIP provider.

Mynetfone: www.mynetfone.co.nz.
MyNetFone service is suited to residential users and small business enterprises. MyNetFone customers only pay 5 cents per minute to any landline, and 39 cents per minute to any mobile phone in New Zealand and Australia at any time, with no monthly fees. They are set up to support Linksys (such as the PAP2T Phone Adapter with 2 Ports), NETGEAR (such as the WGR613V Wireless Router with Voice Adapter) and DynaLink (such as the V100 VoIP ATA) hardware.

gotalk: www.gotalk.co.nz
Gotalk provides a range of wholesale and retail telecommunication services through its own state of the art exchange switching centre. It is optimised to work with D-Link hardware such as the DPH120S VoIP Phone. In Australia, gotalk has established strong corporate partnerships with Harvey Norman, BP, Caltex, Woolworths, Coles, Domayne, Dick Smith, Tandy and Harris Technology.

Skype: www.skype.com
Skype has perhaps the largest installed base of VoIP users world-wide. Most of the VoIP vendors have models that are optimised for Skype including:

• Philips with the VoIP Skype corded phone and VoIP 321 Skype/PSTN cordless phone;
• Logitech cordless Skype handset;
• NETGEAR SPH101 Skype WiFi phone;
• Linksys CIT200 iPhone for Skype.

FAQ