The best VoIP solution is ...

The face of corporate IP telephony has changed considerably within the past few years. No longer simply concerned with pursuing cost savings and efficiencies by amalgamating voice and data infrastructures into one integrated network, VoIP providers are seeking to enable customers to leverage their telephony implementations across a wide range of products and services.

Unified communications (UC), integration and collaboration are today's driving forces. Businesses want to be able to offer cost-effective and seamless communication to all users, regardless of their role within the company or the tools through which they work. It's not just about desk phones running XML applications, but rather extensions following users across multiple platforms — business software, collaborative applications, smartphones and traditional base stations.

This change has been made possible by the infrastructure work implemented by VoIP providers throughout the 1990's — VoIP technology is firmly established as a robust and scalable communications platform over the traditional PSTN model. The recent changes have been driven by the constant merging of disparate technologies — mobile phones are fully web-enabled with high-bandwidth data pipes, and business applications are far more web-aware than has previously been the case. Such an environment is highly conducive to tight systems integration, and a more seamless user experience across platforms.

Although Australia's broadband infrastructure has come under sustained criticism in recent years, it has surprisingly not proven to be a barrier in the take-up of IP telephony. Australia has one of the highest levels of VoIP market penetration globally.

Businesses looking to implement a new VoIP solution or expand their existing investments are certainly spoiled for choice, and the benefits are not only available to the big end of town. Small- and medium-sized companies stand to gain significantly from a data-centric telephony system, and most providers have a solution that can meet the needs of five users or 50,000.

Cisco

(Credit: Cisco)

In a year dominated by the global financial crisis in which every IP telephony vendor saw a reduction in sales, Cisco was the lone dramatic exception with a 37 per cent increase in global sales, making them the number one VoIP solution vendor worldwide. Its market dominance in Australia continues unabated, with a Q4 2008 market share of 39 per cent — three times its nearest competitor NEC.

Cisco has long been recognised as the technical powerhouse driving innovation, development and business uptake in the VoIP and IP telephony markets. The company's heritage as a specialist networking vendor has uniquely positioned Cisco in the market compared with its telecommunications-based competitors, to aggressively promote the convergence of traditional IP and telephony infrastructures through the 1990's. With that legacy Cisco is now concentrating on unified collaboration — the ability to offer customers a seamless end-to-end communications experience incorporating both audio and video, across a wide range of hardware and software platforms while removing the technical specifics from the conversation.

Cisco has at its disposal an incredibly large and diverse product range to architect this vision. The Cisco Unified Communications range from the backbone of Cisco's networked audio, video and presence systems. The Smart Business Communications System (SBCS) is geared towards small businesses of up to 50 users and offers a range of features including Outlook and Lotus Notes integrated messaging, voicemail, conferencing and WebEx support as well as basic firewall and remote access functionality. For bigger businesses is the router-based Unified Communications Manager Express and the server-based Unified Communications Manager Business Edition, supporting up to 240 and 500 users respectively. At the enterprise level sits Cisco Unified Communications Manager, supporting up to 30,000 users per cluster and using a centralised system that allows up to 100 units to be combined into a single system.

(Credit: Cisco)

At the user end sits Cisco's flagship 7900 series of wired and wireless desk phones, handsets and conferencing systems. Each device is supported and will operate with any back-end Cisco system or collaborative product.

Unified messaging is managed via the Unity range of products. Unity Express is the entry-level system, providing up to 250 mailboxes and can be integrated as an add-on with other systems like the 2800 series router. The main Unity product is designed for enterprise deployments. It integrates tightly with Microsoft Exchange and IBM Lotus Domino for a single-inbox user experience, as well as with Unified Communications Manager and legacy third-party voicemail systems. The latest version of Cisco Unity is supported on VMware, making it ideal for large-scale datacentre deployments.

Cisco's 2007 acquisition of cloud software company WebEx has enabled it to bring SaaS collaboration into its product range. Apart from maintaining the traditional WebEx functionality, Cisco has extended it with Unified MeetingPlace, which is an on-premise installation allowing users to host and attend WebEx-based meetings with a rich audio, video and desktop sharing experience. Because it's on the premises of a business it has the added advantage of LAN bandwidth, security, integration with corporate applications and bandwidth cost savings, not to mention external customers can be brought into the meetings. For an advanced video experience, WebEx can be extended with Unified VideoConferencing, which integrates with Cisco Telepresence to provide high-definition video across standard VoIP protocols.

To extend the ability to communicate seamlessly while on the move, Cisco supplies the Unified Mobility and Unified Mobile Communicator products, which allow incoming calls to a corporate extension to be routed to up to four devices including desk phones and mobiles. Mobile users will still be able to access directory information and voicemail data, and collaborate via Unified MeetingPlace. Additionally, iPhone and smartphone users can fully participate in WebEx meetings. Mobile Communicator is also part of the suite of user presence applications, including the Unified Personal Communicator softphone and UC for Microsoft OCS and IBM Lotus Sametime.

Cisco has what appears to be a bewildering range of products and it can be difficult for a business to accurately architect an appropriate solution, which is why Cisco relies so heavily on its partners and resellers. However, Cisco itself stays in the conversation via technology showcases so that customers can get a feel for what their options are. It may also seem that a complete Cisco implementation of any size involves purchasing a lot of disparate products and forcing them to play nicely, but this is not the case. All Cisco Unified Communications products are designed to support and integrate seamlessly with each other, and while there's no doubt that Cisco doesn't offer the most financially accessible options on the market, it has a solution for every scenario and every product is built around what Cisco does best — networking.

Nortel

(Credit: Nortel)

Until it very recently overtaken by Cisco, Canadian telecommunications giant Nortel was the market leader in IP telephony, supporting massive global infrastructural projects such as the 2012 Olympics in London as well as hundreds of thousands of customers worldwide.

The company itself is currently in a state of flux, as it filed for bankruptcy protection in January 2009 in Canada, the US and UK, and is in the process of selling off its business units. Ericsson successfully bid for Nortel's CDMA/LTE infrastructure, and Avaya has a public stalking horse bid for the Enterprise Solutions unit. The impact in the Australian market will depend on which company eventually buys the relevant business division, and what their current presence in the Asia Pacific region is. Regardless of the outcome, at the moment it's business as usual for Nortel.

Nortel's IP telephony solution for small and medium businesses revolves around the Business Communication Manager 200 and 400 devices, each supporting up to 90 IP stations (desk phone and softphone). Both systems use effectively the same hardware, but the BCM 400 supports four media bays compared with two, and also hardware redundancy. The devices can act as fully-featured edge devices, with integrated firewall, VPN and routing, and support digital stations as well as IP, so they integrate with existing voice infrastructure. As VoIP devices they support up to 60 IP trunks as well as SIP trunking, mobile IP devices, voicemail and ad-hoc conference calls. They also integrate with Nortel's Advanced Paging Productivity Pack, which offers a range of one-button paging options throughout the telephony network.

For large, multi-site or geographically disperse environments, Nortel offers the Communications Server 1000 and 2100 IP PBX systems. The 1000 series supports up to 22,500 IP users per server, and multiple servers can be chained together and scaled as the environment grows. It handles all types of stations, from pure IP to analog, has internal hardware redundancy and can also offer system redundancy across campus or geographical WAN links, maintaining the integrity of the telephony network even in the event of critical hardware failure. The CS1000 also seamlessly integrates with the BCM range of devices, allowing branch offices to be transparently managed from one central location.

(Credit: Nortel)

Unified communications on the CS1000 is achieved by Nortel's Converged Office suite, which integrates with Microsoft Live Communications Server and Office Communications Server. Clients can use the softphone features of these products as an IP endpoint on the CS1000, which seamlessly connects to and authenticates against Active Directory so there is no need for separate user provisioning. The system features a gateway for PSTN connectivity, SIP call bridging and auditing of OCS-originated calls.

Designed to integrate with the CS1000, Nortel's Multimedia Communication Server 5100 offers the full range of rich collaboration functionality — audio and video conferencing, presence, desktop sharing, web collaboration, instant messaging and access from smartphone platforms. Because it supports open SIP standards, the MCS5100 will interact with non-Nortel PBX or VoIP systems, and each system can scale to support up to 20,000 active subscribers. Additional user support is achieved simply with extra devices.

The CS1000 is likely to have more than enough capacity for the vast majority of business scenarios, but if not then the CS2100 offers a carrier-grade, massively scalable option. Powered by Compact or XA-Core and designed around the centralised datacentre model with full hardware redundancy, each device can support up to 125,000 IP or digital stations and 200,000 IP trunks. Geographical redundancy is possible up to a range of up to 100km, so the CS2100 is perfectly suited to intense, multi-site configurations, and there is a full range of PC clients as well as full integration with Microsoft OCS.

Both the Communication Server systems support a massive range of IP telephony features, open networking protocol standards, encryption, media gateways and significantly more. Businesses in the market for such a solution will require significant and ongoing consultation to architect an effective solution.

Nortel also produces a wide range of IP and SIP desk phones (also produced by LG-Nortel) and wireless handsets, which are largely compatible with all of Nortel's back-end IP PBX systems as well as third-party devices. There are also softphone products available for smartphone and mobile phone platforms, giving mobile users full access to the corporate telephony system.

Although the company is undergoing major changes its product range is still very strong and shows no signs of diminishing — Nortel is still actively winning contracts globally.

Avaya

(Credit: Avaya)

In 2008, US-based telecommunications company Avaya finished in third place in the list of top IP telephony companies globally. In 2009, Avaya introduced its software-based PBX product — Avaya Aura — which replaced the long-running Definity series of PBX hardware. Aura is a Linux-based communication platform driven and unified by Aura Communication Manager.

Communication Manager is at the heart of the Aura system. It's a software PBX that supports the usual open standards of SIP and H.323, and can manage up to 18,000 IP stations per system and can scale up to 1 million stations per network. The system sits on Avaya servers and gateways, which can be mixed and matched to meet the changing needs of the business. In this sense, the Avaya "network" consists of the combined functionality of all the underlying hardware, while the software and thus the PBX functionality is abstracted, giving customers much greater flexibility to create and maintain a dynamic telephony environment.

There are four models of Avaya servers, from the S8300 series that support up to 450 stations to the fully hardware-redundant S8700 series which can handle up to 18,000. The S8400, S8500 and S8700 can all support the full range of available media gateways, which are the physical endpoints within the Avaya network. The gateways provide support for extensions, physical telephony media (eg, T1/E1), station platforms and trunking. Because they are modular, they can be expanded as required and deployed to meet the physical requirements of a site or branch office.

Avaya Integrated Management is used to centrally manage all aspects of an Avaya network across multiple sites and branches. Leveraging off Microsoft Network Management, this product lets administrators constantly monitor the state of individual devices on the network, track network health, and apply patches or firmware updates to IP phones as well as media gateways. It can also act as a central file repository for WAV files used for broadcast announcements.

(Credit: Avaya)

Unified communication and collaboration is provided by Aura Application Enablement Services (AES), Communication Manager Messaging and Presence Services — these are all separate products. AES provides an integration framework for Communication Manager to interface with Microsoft OCS and IBM Lotus Sametime, but it also provides a development platform and APIs for internal software writers to add telephony functionality to in-house line of business applications. AES is available as a software-only deployment, which just provides the APIs and SDKs, whereas the hardware/software deployment features the full product on a dedicated Dell server. Communication Manager Messaging provides voicemail functionality based on the physical specs of the underlying Aura servers — for example, the 8300 series can support 450 mailboxes, whereas the 8400 series can manage 900. Presence Services enables connected users to see the online status of all other users within the Communication Manager network and across connected Microsoft and IBM Lotus systems.

The Aura system is very much geared towards medium to very large businesses and is not particularly cost-effective for smaller customers. For this section of the market, Avaya has the IP Office phone system. IP Office is available in three formats — Essential, Preferred or Advanced Editions — and user functionality can then be added via productivity products, for example, Mobile Worker or Receptionist, for access to features like softphones or mobile integration. IP Office Essential offers basic functionality via an IP Office 500 physical system — voicemail and message control, with a maximum of four concurrent calls. IP Office Preferred expands this functionality with secure conferencing, unified messaging with an IMAP-compatible mail system, call recording, automatic call routing and 40 concurrent calls. IP Office Advanced offers more control over individual calls and voicemails, and is very much geared towards customer contact centre environments. Because all these systems use the same Avaya hardware, it is easy for a business to upgrade to meet growing needs. Additional server resources are handled using standard Windows Server systems.

Avaya also supplies a range of wired and wireless phones — IP, digital, DECT and wireless as well as videophones and attendant consoles, all of which are compatible with the media gateways.

Avaya's distributed, modular approach offers significant flexibility and cost savings, as well as limiting the need for hardware changeover in order to bring new functionality online. The IP Office solution is also compelling for small businesses, giving them access to IP telephony at an affordable price point.

NEC

(Credit: NEC)

A big player in the IP telephony market, both here in Australia and globally, NEC's VoIP infrastructure is centred around its Univerge SV8000 series of communications servers and DT series of terminals.

Approximately 40 per cent of NEC's new sales in Australia are pure VoIP implementations. The rest still require some sort of analog telephony support (legacy systems, fax lines, etc), and the majority of NEC's customers are running hybrid systems. Although they are native VoIP products, the SV8000 range all support analog/circuit-switched technology and are designed to easily integrate with existing infrastructure, whether the hardware was manufactured by NEC or by another vendor. For existing customers, NEC has a migration path available so that any of their systems made within the last 15 years can be easily migrated to a pure VoIP infrastructure with minimal expense.

The SV8000 range is split up into three main product groups, aimed at small, medium and large businesses respectively — the SV8100, SV8300 and SV8500. The SV8100 is available in two builds — the rack-mountable SV8100 and the floor/wall mountable SV8100 Model SE, which is smaller and supports fewer trunks and terminals but can be migrated to the SV8100 to accommodate expansion needs. This unit is suitable for businesses with as few as 10 users — NEC considers that smaller environments are unlikely to see that much cost benefit in a full VoIP implementation.

The SV8100 can handle VoIP server and media gateway/converter functions, and can support up to a maximum of 512 DT700 terminals in a peer-to-peer environment. Up to four SV8100's can be joined to handle more trunks and ports; beyond four businesses should be considering the SV8300 for cost-effectiveness. The system also supports NEC's VM8000 InMail and Automatic Call Distribution (ACD) technologies, as well as the SV8000 Desktop Suite, which incorporates the PC Assistant, PC Attendant and the SP310 softphone.

The SV8300 is a stackable rack-mount system designed for medium enterprises. It is the backbone of NEC's Univerge 360 marketing campaign and supports up to 1536 terminals and 512 peer-to-peer IP trunks. A wide range of applications are available on the system and are activated using a licensing model, so that businesses can simply turn on features as and when required. NEC's customers have driven the demand for open architecture so as to better facilitate unified communication scenarios and tighter integration with critical business applications, so the SV8300 features an Open Application interface, including SIP and XML.

At the top end of the Univerge 360 campaign is the SV8500. Massively scalable to support the most widespread and intensive communications infrastructure, it can support over 6000 trunks and 192,000 users and has optional expansion features to support CPU and power supply redundancy. It will also support SIP trunking once that technology becomes more widely available in Australia, offering further cost savings in terms of toll bypass set against the attractive deals which telcos are traditionally able to offer large corporations.

(Credit: NEC)

For full unified communications, NEC has the Univerge OW5000. It's an open source application platform that allows developers to extend telephony support to a wide range of internal business systems, like Microsoft OCS and IBM Lotus Sametime. It can integrate with multiple PBXs and supports a swathe of open development standards, including C++, Java and .NET.

At the user end sits the DT modular handset — the DT700 range of IP terminals. The entire range is based around a standard chassis that can be completely customised to meet business needs, from the number of buttons and screen type right down to matching corporate logos and office decor. All the phones support XML for custom applications, VoIP protocol encryption and IPv6. The next generation of these handsets will feature an integrated VPN client, allowing users to take handsets home and connect securely back to the corporate network via a third-party VPN concentrator, and will also feature a Bluetooth hub. All the DT700 handsets as well as the digital DT300 handsets are compatible with the SV8000 communications servers, so any back-end infrastructural changes won't necessitate a client-side hardware refresh.

With the industry and consumer push towards cross-platform communications, NEC also has a softphone application for the Apple iPhone, which allows the extension to be used on the iPhone independent of the desk phone. There are also "tethering" applications available for Nokia and Windows Mobile-based phones which route traffic via the desk phone, but fully-featured softphone apps for these platforms will soon be made available.

An experienced telecommunications provider with decades of experience, NEC is a solid option for any business looking at implementing a new IP telephony solution or expanding existing infrastructure. SOHO and small business might find NEC something of an expensive proposition, especially if there's little plan for future expansion.

Alcatel-Lucent

According to a May 2009 Gartner publication, French telecommunications company Alcatel-Lucent finished 2008 with an 8 per cent share in the global IP telephony market, placing it sixth in the top list of major players.

The core of Alcatel-Lucent's IP telephony suite is the OmniPCX Communication Server. This is available in two main formats — the Office CS, which is designed for small to medium companies; and the Enterprise CS for large-sale deployments.

The OmniPCX Office CS is a pre-configured server and comes in five different editions, each supporting a growing range of users, from six up to 200. It's designed as an all-in-one business server, incorporates edge functionality such as internet NAT router, proxy server, web/DNS cache and firewall. It also supports VPN tunnels for remote access and site-to-site connections plus it can act as an intranet and DHCP server. As a call server it supports automatic call distribution (ACD) voicemail, call screening, voice recording and all handset platforms including digital, analog and mobile.

The functionality of the Office CS can be enhanced with the addition of the Extended Communication Server — the Compact Edition supports up to 25 users while the Premium Edition scales up to 250. The system runs a Linux OS installed on desktop-class hardware. The ECS has a number of built-in collaboration and communication applications, like a secured collaboration virtual desktop, connector software to sync shared calendars and contacts with Microsoft Outlook. It acts as a mail server and also provides DNS, PKI and QoS functionality, and supports push technology for mobile users, as well as a mobile version of the virtual desktop.

Designed for medium to extremely large global companies, the OmniPCX Enterprise CS supports up to 15,000 IP users on a single server, but multiple servers can be chained together to support 100,000 users across a single network image, or over 2 million users across a scaled, geographically distributed network and supports a wide range of open standards including SIP and H.323. It is bundled with OmniTouch 8600 My Instant Communicator, which is an integrated multimedia service offering online collaboration, IM and presence, as well as software integration with Microsoft Office and IBM Lotus Notes/Sametime. The OmniPCX Enterprise CS also features Advanced Cellular Extension, which extends full system functionality to Windows Mobile, Nokia and BlackBerry devices.

For medium-sized businesses who are expanding but are not yet ready for the expense of a full Enterprise CS implementation, Alcatel-Lucent has created the Business integration Communication Solution (BiCS). This is a single-server solution built on Enterprise CS targeted at businesses with up to 1000 employees who are looking for an affordable, unified approach to business communications. It incorporates OmniTouch Contact Centre, My Instant Communicator and fax services, and supports XML APIs for integration with third-party business applications. Each feature set is licensed separately and can be switched on as the business expands. BiCS offers a single point of management and a unified network infrastructure for both wired and wireless IP stations, and the can be implemented across multiple sites. BiCS is managed via OmniVista 4760 Network Management, which is a Java-based web tool for administering the Enterprise CS system, and which offers an embedded LDAP directory, reporting and real-time topology and performance analysis.

The end user experience is handled by Alcatel-Lucent's range of 8 Series IP Touch phones. There are five models available, ranging from the entry-level 4008EE to the deluxe 4068EE which supports gigabit PC connectivity and integration with any Bluetooth 1.2-capable wireless headset. All the desk phones are compatible with all of the OmniPCX communication servers and can be expanded with the addition of multi-button modules for extra direct-dial access or switchboard functionality.

Alcatel-Lucent's clever use of product bundling for small and medium businesses is an attractive approach. The Extended CS and BiCS represent excellent opportunities for companies to implement new IP telephony systems or expand existing ones without incurring huge expenditure or installing large amounts of new hardware. The fact that these systems also operate as edge devices means that they offer considerably more value than a stand-alone VoIP device, and would make an excellent infrastructural choice for new businesses.

ShoreTel

(Credit: ShoreTel)

Based out of the US, ShoreTel is a particularly interesting player in the pure VoIP market with a pitch that says: "the best product, not the best marketing". Unlike the vast majority of IP telephony vendors, the functionality of ShoreTel's products is centred around its software applications rather than the feature sets of their hardware. This means that a ShoreTel VoIP implementation uses a distributed architecture model which has some extremely beneficial flow-ons.

The physical infrastructure of a ShoreTel system revolves around the ShoreGear range of voice switches. Depending on the business, the number of physical handsets that need to be supported, and other considerations like support for analog trunking, there is quite a variety of voice switches available. Ranging from the half rack-width ShoreGear-30 (approx US$1300) which supports up to 30 IP phones and four analog ports, to the ShoreGear-220T1A (approx US$5500) which supports 220 IP phones or 70 phones and a T1 connection, ShoreTel supplies a wide variety of systems to meet the specific physical requirements of a business site. Each switch communicates via the Media Gateway Control Protocol (MGCP) with all other switches, IP phones and softphones, and will integrate with both legacy and current-generation PBX systems.

Although the core functionality is contained within the switches, all control and management is centralised using ShoreWare Director. This is a web interface that handles management for all voice applications, regardless of the number or layout of the ShoreGear infrastructure. Rather than having to individually manage each device on the system, the Director interface presents a unified view of the overall system resources, despite their physical location (including cross-site). Because core functionality is unified across all ShoreGear devices, each switch can pick up and balance the load (depending on capacity) in the event of device failure. Using this methodology ShoreTel is able to avoid single points of failure and provide N+1 redundancy, compared with all other IP telephony vendors that are effectively locked into a 1+1 redundancy model, where available.

The user end is supported by a range of ShorePhone IP handsets which come in a variety of shapes, sizes and feature sets, including 24-line expansion boxes, gigabit Ethernet, Bluetooth headset compatibility and an integrated VPN client. Prices range from approximately US$130 to US$500. Users also have access to softphone technology via the ShoreWare Call Manager application.

(Credit: ShoreTel)

Unified communications capabilities are built into the system rather than as an optional add-in. The ShoreWare range of messaging products provide native access to voicemail, messaging, desktop video and user presence. The system will also integrate with third-party PBX voicemail and UC systems like Microsoft OCS or IBM Lotus Sametime. There are also optional add-on applications to support integration with systems like Microsoft CRM and Salesforce.com.

This approach offers some rather intriguing benefits by effectively abstracting the software component from the hardware, allowing businesses to treat and manage the two as separate entities. Due to software upgrades not being dependent upon hardware capabilities, hardware changes are dynamically reflected in the software and with licensing handled on a per-user basis, which according to ShoreTel, serves to drive down the TCO of its VoIP range. This, combined with its claim that switches consume around 60 per cent less power than the equivalent Cisco systems, means that customers are going to ShoreTel to benefit from reduced TCO. It also means that ShoreTel does not need to create expensive migration and roll-over roadmaps for its customers — the system simply expands to meet growing demand.

Because of the scalable nature of its products, ShoreTel doesn't really have to differentiate between small, medium and large customers. Having said that, it does have an upper support limit of 10,000 users and admits that the "sweet spot" of its customer base is in the 50 to 6000 user range. ShoreTel also produces and markets a Small Business Edition product, which is a switch, UC and user licence bundle designed as an affordable single site implementation. Again, because it's based on the standard range of ShoreTel products, expansion beyond the limits imposed by the SBE model is achieved via a software upgrade rather than a hardware changeover.

ShoreTel's distributed approach to pure IP telephony is quite innovative and well worth considering. It does not have a large presence in Australia at present, but is expanding rapidly.

Asterisk/Digium

(Credit: Digium)

Asterisk is an open-source IP telephony PBX and is freely available for download.

Like many Linux-based point solutions, Asterisk is designed to do one thing and to do it well. Its development is driven by Digium, the US-based company which originally released Asterisk, and is supported by the open source community.

Asterisk is released under a dual-licensing model which allows both proprietary and open source releases, so like many other open-source business applications, it is available as both a free, unsupported download or as a paid-for business product.

Asterisk is extremely flexible, capable of acting as a PBX switch, media gateway or call centre manager. It can act as the main device in an IP communications network or as an interface with an existing PSTN-based PBX. It supports a wide range of call features, telephony codecs and protocols, including SIP, H.323 and SCCP. It has been primarily developed for GNU/Linux on the x86 platform, but also works on FreeBSD, OpenBSD and Mac OS X. There is a Windows port of Asterisk called AsteriskWin32, but it is at least one major revision behind the primary source code build and has very limited support.

Asterisk is designed to be a cross-platform back-end product, so its implementations do not follow the traditional end-to-end model available from most vendors and resellers. There aren't any specific desk phones designed to work with Asterisk nor softphones available via the code project, so all these things have to be sourced separately. Fortunately, there is a thriving online community to assist in the search for compatible accessories, and there are compatible softphones like X-Lite and Firefly that are commercially developed and supported.

Since Asterisk is open source it comes free of charge with no licensing considerations. However, as with any enterprise system, there are always hidden costs. Asterisk is not a particularly accessible platform to those unfamiliar with telephony configuration, and even though there are plenty of tutorials and articles about how to configure the system, businesses looking to implement Asterisk based on the open source build will need to rely heavily on pre-existing in-house expertise or will have to bring in external contractors. There is a preconfigured Asterisk soft appliance available called AsteriskNOW (also free) which is much easier to get up and running, but ongoing support and configuration will still need the attention of a specialist.

Another option is to go through a reseller. Asterisk is popular enough to support a global network of partners and distributors who can implement and support Asterisk, either on third-party hardware or using the pre-configured systems built and supplied by Digium.

Digium supplies two main hardware systems: the Switchvox IP PBX and the Asterisk Appliance. Switchvox is Digium's IP PBX platform based on Asterisk, and is not open source. Designed to be much more accessible than Asterisk, businesses can download a trimmed-down free version of Switchvox to use on its own hardware. Digium has SOHO and SMB versions of the product that run on the company's own hardware appliances, which offers greater functionality and supports more users and features. Switchvox SOHO is designed for one to 20 users and is available for a starting price of US$1595, while the SMB systems scale to accommodate up to 400 users and has a wider range of support and maintenance subscriptions.

The SMB appliances come in three models: the AA60, which is a desktop/wall-mount device suitable for up to 30 users and starts at US$3195; the AA300, which is a rack-mount device supporting up to 150 users and starting at US$4195; and the AA350, which is a rack-mount system with hardware redundancy supporting up to 400 users and available from US$5995.

All Switchvox systems support a range of add-on software packages to enhance user functionality; such as the Notifier Suite (for SMB devices only), which integrates with Microsoft Office enabling full access to the PBX account; Fire Dialler, which brings VoIP functionality to Firefox; or the stand-alone Outlook plug-in. Digium also supplies a wide range of telephony expansion and functionality cards designed to work with any Asterisk-based server.

The Asterisk Appliance 50 (AA50) is a stand-alone system designed for SMBs or branch offices with up to 20 users. It uses an embedded build of AsteriskGUI and can function as a PBX, voicemail/IVR/conferencing server or VoIP gateway. It's available in three hardware formats — a pure VoIP system (S800i), an eight-trunk system (S808B) or a four-trunk plus four-station system (S844B). Each system is available with Silver, Gold or Platinum maintenance subscription, starting at US$1259.50 for the S800i/Silver product and ranging up to US$2579.50 for the S808B/Platinum system.

While the open source approach does not suit every business, the ability to implement low-cost IP PBX infrastructure is an attractive one worth investigation, especially as affordable, supported systems are available. Asterisk-based solutions are the most suitable for small to medium businesses rather than large enterprises, as neither the free product nor Digium's business model is designed to scale that far or support complex environments.

Conclusion

All the vendors in this feature are top market players, and as such they all offer exceptionally strong business-orientated products. Any of them would work well in almost all business environments, but if we had to make recommendations read on and see what we'd choose.

The small business offerings of every vendor were quite good, but the standouts were Avaya's IP Office, Alcatel-Lucent's Office Communication Server and Asterisk/Digium's Appliance 50. All of these products offer significant integrated functionality at an affordable entry point — perfect for businesses with few users who will want the benefits that come from a unified data and voice system. Of these products, the one that interested us the most was definitely Alcatel-Lucent's Office CS, which has the capacity and flexibility to serve as an integral core device in any small business.

For medium-sized businesses (around 50-1000 users), the vendors of particular interest are Cisco, ShoreTel and Avaya. ShoreTel and Avaya's distributed approach to hardware and software (especially ShoreTel's) offer fantastic options for flexibility and scalability while keeping down TCO should definitely be considered. However, the staggering variety of Cisco's product offerings across such a wide range of business solutions make them impossible to pass up. The ability to enable seamless communications across multiple platforms is exceptionally compelling.

For large and very large companies, all the vendors apart from ShoreTel and Asterisk/Digium have powerful, massively scalable solutions that are more than up to the task. The reality of projects of this size is that they are more than likely to have a political element — pre-existing relationships with partners, currently-deployed hardware, personal preferences of decision-makers, and so on. Though, again, Cisco comes to the fore because its collaboration solutions scale up to match the size of the underlying network. Its networking heritage also allows an holistic approach at all times, and due to this Cisco should really be the vendor of choice for enterprise IP telephony. And given that Cisco is now the number one vendor globally, the market seems to agree.