This content is part of the Buyer's Guide: Choosing a VoIP vendor: A buyer's guide

What you need to consider before you buy VoIP

When assessing VoIP systems, first consider VoIP features and functions, then gauge the scope of the service, network needs and plans for expansion.

Selecting a VoIP service provider requires careful consideration for two distinct reasons. First, you need to determine from whom you'll be buying. In most cases, you will buy VoIP via a reseller or dealer -- the channel -- but in some cases, businesses buy VoIP direct from the vendor. Secondly, buying a VoIP phone system has more variables than a legacy phone system. In some cases, the need is for a full-fledged IP phone system, while others might just want basic IP phones.

Furthermore, IP phones are increasingly bundled with other things, such as the VoIP service, broadband connectivity and SIP trunking. A comprehensive set of buying criteria will depend on the needs of the organization, but the four common criteria that will apply to all VoIP phone system scenarios are: VoIP features, scope of the service, network requirements and plans for future expansion.

Ease employees into VoIP features and functions

Considering features and functions should always be the starting point when you are ready to buy VoIP. To get full value, products should be compared with modern VoIP offerings rather than an organization's existing time division multiplexer (TDM) service. At minimum, VoIP must replicate legacy telephony, especially to ensure easy adoption among employees. The phones should have a familiar look and feel with the dial pad, preset buttons, handset, visual display and volume controls.

Businesses need to define their VoIP objectives beyond just buying a phone system.

Beyond this, however, VoIP supports new features such as ad-hoc conferencing, call recording, Web browser, presence indicator, Bluetooth support and more. Since these phones connect to the data network, there will be different power configurations. Some models will be powered by plugging directly into the power supply, but most will use Power over Ethernet.

In terms of must-have VoIP features, the most important factor is ensuring the phones support the features being offered by the VoIP provider. Some phone vendors still maintain proprietary protocols, especially for SIP trunking, so choosing a vendor should not be done in isolation from the VoIP service. Another example is high-definition voice, which can be a great feature for the contact center or conferencing, but only if the endpoints can support it.

Finally, the range of VoIP features varies by price point, and IP phone vendors offer a range of models to address different use cases. While most employees can manage with a standard phone model, executives might want higher-end phones. Contact center agents need models with good headset support. Warehouse employees need more rugged and/or cordless phones. And meeting rooms require conferencing phones. When developing a request for proposal, identifying the various needs will be a key area for vendors to tailor their offer.

Grasping the scope of VoIP service

Unlike TDM, VoIP is not restricted to the desk phone and can take several configurations. This is a key area where telephony consultants add value, as businesses that are new to VoIP may not understand the range of possibilities. Legacy telephony was straightforward since the service ran on a dedicated voice network, but VoIP supports connections to a variety of technologies through the Internet.

Organizations that purchase VoIP will at least need a standalone phone system, such as when the business has adequate network support for VoIP and does not need SIP trunking. This would be a bring your own broadband model, where the vendor provides a phone system that IT manages.

However, even this scenario will require additional network elements to support VoIP, such as media gateways and session border controllers. Furthermore, businesses may elect to keep some legacy phones and VoIP-enable them; in that case, Analog Telephone Adapters are needed.

Another consideration is maintenance and professional services, where the range of offerings is quite broad depending on the support the business needs. Prime examples include system design, installation, system configuration and training -- for both IT and end users.

Additionally, there is the option of either cloud- or on-premises-based, and this can have a major impact on the specifications. These are just a few examples of what scoping out the service entails. And for first-time VoIP buyers, the importance of doing this up front cannot be understated.

VoIP could require network overhaul

When considering the overall operational requirements for VoIP, buying a phone system is only half the equation. Moving to VoIP will trigger a series of network-related questions, as businesses can cut over completely or in phases. This decision can have major implications for the project's scope, as VoIP marks the beginning of a transition away from having a separate network infrastructure to support telephony.

Ideally, the data network is able to absorb VoIP traffic, in which case only the new phone system needs to be acquired. More likely, however, the LAN will need some form of upgrade or expansion.

While VoIP is not a bandwidth-intensive application, adding a lot of traffic from the start could impact performance. More importantly, data networks are not designed to support real-time modes such as voice, and this is where IT faces the biggest challenge. Aside from possibly needing to upgrade cabling or capacity, new network management tools and hardware may be needed to prioritize voice traffic and ensure quality of service (QoS).

Another variation would be to route voice over a separate data network. Some businesses do this to achieve a higher level of data security, as VoIP traffic can be an easy target for cyberattacks. While this may seem to negate all the benefits of taking voice off the dedicated TDM network, businesses do get all the benefits that come with VoIP, but in a more secure manner.

Beyond this, there are additional network-related considerations around SIP trunking and Wi-Fi. Both can enhance the value of VoIP for the business but have implications on the network and infrastructure required to support the phone system. As such, when developing buying specifications, the network needs must be taken into account.

Plans for future expansion with VoIP

Legacy phone systems were bought to do one thing, so there is little need to think about their future. TDM innovation has been stagnant for decades, but VoIP is evolving. Today, businesses do not buy VoIP phone systems with a 15-year horizon. And businesses should keep in mind that the role of voice communication is not defined solely by VoIP.

In the broader context of mobile broadband, WebRTC and cloud communications, businesses need to define their VoIP objectives beyond just buying a phone system. The business value of VoIP is based as much on the utility of desk phones as the ability to integrate VoIP with other applications and communication modes. To address this, telephony vendors have higher-end models built to support multimedia requirements, and some offer docking stations to support tablets and smartphones for office use.

On the network front, most businesses still prefer to be based on premises or have a mix of on-premises and cloud-based systems for their VoIP environment. Only a minority is currently ready for a full cloud migration.

And when planning for VoIP, the safest course is to partner with a vendor that can support a hybrid service. Vendor capabilities vary widely, so businesses need to determine which services best align with their long-term needs.

Making decisions when you decide to buy VoIP can be simple or complex, but in most cases, there will be several considerations beyond the basic phone system. VoIP features bring exciting opportunities to any business, but the range of deployment scenarios can be daunting. For this reason, choosing the right vendor is critical, especially since apples-to-apples comparisons cannot be made for every attribute.

If you're replacing TDM with VoIP and integrating VoIP features with a broader communications landscape, you will have more success if you develop a clear set of needs.

Next Steps

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