SIP at the Desktop

10 min read Networks & Network Services
A growing rate of adoption for SIP trunks has resulted in a number of new entrants to the SIP desktop phone market and a wide range of options for resellers. Comms Business Magazine reports.

With the growing trend towards Softphones, BYOD, Unified Communications and headsets many observers believe that the desk phone is now on the brink of extinction

We think that is far from being the case and that the desktop phone has a long life ahead of it and so we decided to take a look at the latest generation of devices to land on the desk – the SIP phone.

Key amongst any features that these phones may or may not offer the user is interoperability with the vast array of phone systems and platforms on the market so we started off by asking channel players about their interop testing.

Interoperability testing

Richard Bennett, EMEA Director & CTO Lead at Avaya says his firm is in the business of interoperability and make it their aim as a vendor to be conscientiously open.

“Session Initiation Protocol (SIP) has tremendous potential to enable multi-modal, multi-media services. Using an open standards protocol like SIP, businesses can take full advantage of their entire communications portfolio by integrating applications and making them work together; regardless of the number of different vendors they are using.

Of course to get to this stage, thorough testing is absolutely necessary and we ensure we do this for all our customers. By taking an open standards approach now, businesses can guarantee fewer compatibility issues in the long run.”

Interoperability is a battlefield for SIP and IP phones says Jason Green, Director UC & Online Marketing at snom.

“Vendors unable to qualify as interoperable or compatible with the leading UC platforms such as Microsoft Lync and Broadsoft, as well as for the major IP PBXs will struggle to compete for market share. The snom development team trail blazed SIP telephony and has created a software basis that is inherently and intuitively interoperable, being for example the first vendor to receive qualification for Microsoft OCS and now having a portfolio of six fully-qualified devices for Microsoft Lync 2013.

We believe that reports of the demise of the SIP and IP desk phone have been wildly exaggerated.”

ProVu Managing Director Darren Garland says that a thorough interoperability testing programme is essential if a Service Provider wants to integrate any end point with its platform, as well as testing the hardware it should also mandate specific firmware versions to be used with the hardware.

“Invariably SIP phones will be supplied on a differing version of firmware than the mandated version, so it is important that either the distributor or the Service Provider have the ability to automate the provisioning of firmware when a SIP phone is first set up on the platform, if any scalable numbers are to be achieved cost effectively.

Paul Burn, Head of Category Sales at Nimans, says SIP is obviously an open standard but manufacturers have various flavours regarding what features will transfer through and which ones won’t.

“Yes, there is testing but the big problem is that things can quickly change so it’s not always easy to keep up to speed. You couldn’t possibility test all the end points for one particular system because when the manufacturer brings out a slightly upgraded version of that platform you’d have to test them all again. Continuously testing SIP end points would be like painting the Forth Road Bridge.  In the real world interoperability testing isn’t really an issue for resellers as most end points marry-up to the same system brand.”

Alexis Argent, founder and director, VoIPon Solutions, 4Gon Solutions believes that interoperability testing is essential, and SIP phone manufacturers are now making sure their products are interoperable with all major new platforms.

“SIP is an open standard, and extremely flexible. The IPPBX can be hosted, or SIP phones can connect locally. The nature of SIP as an open protocol is that it can be interpreted differently, so it’s important for SIP manufacturers to consistently test the phones are interoperable. This is now a necessity.

Take Microsoft Lync, more and more phones are interoperable with this proprietary system, which is great. Lync is still an IP product and so part of the new world of business comms. Everyone is scrambling to work with Lync, but Snom is an example of a manufacturer that’s been ahead of the curve and got a product that’s now very slick and works well.”

Ease of set up on different platforms?

Richard Bennett notes that at Avaya they have developed an open, SIP-based architectural model that provides customers with choices in the vendors, applications and deployment models that they wish to use.

“Once the systems have been tested and interoperability has been established then setting up on different platforms is very easy.

As well as third-party party endpoint support, Avaya also provides fully open interoperability for third-party applications. This enables a business to embed SIP communications fully inside its existing business applications or services through our Collaboration Environment (CE).

We have also created comprehensive Compliance Testing programs through the Avaya DevConnect programme, for all sorts of third-party SIP-based solutions. Our aim is to demonstrate interoperability with Avaya Aura and related Avaya products.”


Garland at ProVu believes that the key to setting up SIP phones on any platform is to have good provisioning and on-going management, trying to manually set up SIP phones is time consuming and prone to errors, on-going management of firmware and settings is essential for service support and trouble shooting.

“At ProVu we much prefer to work with SIP phone vendors that have their own re-direction server, thus allowing SIP phones to be provisioned and delivered without actually taking them out of the box This cuts down logistical costs for our customers and minimises errors. Furthermore should a unit be factory reset at any point in its life the channel partner will still be able to access and control the device, essential when trouble shooting or updating firmwares.

We often work with Service Providers to agree a provisioning template and they then send their resellers to us. The Service Providers then has the confidence that their resellers will get the correct product with the correct firmware and the correct provisioning details, this then cuts down deployment and support issues for everyone. If the Service Providers requires a change in its template they will liaise with our engineers and then all their channel partners will receive a corrected version when purchasing from us. In some cases we automatically register the MAC addresses that are being shipped into the resellers account on the Service Providers portal, thus cutting down the work required by the reseller even further and further minimising errors.

Firmware control is also essential, a Service Provider will not only dictate what SIP phones they will allow on their platform but which firmware will need to be used. More often than not the phones will be supplied on firmware that is not the correct one for the SP. This is where good provisioning is required to handle these firmware transitions.

Paul Burn at Nimans believes that generic SIP and IP end points tend to be much better suited in the hosted environment or with something like their own iQ PBX IP platform. ‘There’s more choice and more opportunities’.

“SIP is SIP at the end of the day and some very basic features will always travel though. But generic end points are much better suited in the hosted world. Resellers understand this. It comes down to safety and common sense. In general, manufacturers will say end points work across different platforms but with a caveat that you connect them up at your own risk.”

Alexis Argent, founder and director of VoIPon Solutions and 4Gon Solutions, “The easier and faster it is to set up a SIP phone, the better, anything that saves resellers time, saves them money.

The leading phone manufacturers all support provisioning systems, which are pre-configured according to the SIP phones mac address. This is the easiest way to set up a SIP phone on an IPPBX.

Anything you can configure on the phone manually can be put into a provisioning system, from the simple, such as the host name / IP address, extension and password, to the more complex such as voicemail, address contacts and forwarding.

I’d argue that SIP phones should be platform agnostic, as all IPPBX’s require more or less the same information at a basic level. Each platform should fundamentally make it as easy and intuitive as possible to put that information in. However, some platforms do provide slightly better technical means for inputting the SIP phones details, than others. You can either do it line by line, or by batch with a CSV file, generated in Excel for example.

Having a provisioning system used to be a smart, nice-to-have element. Now however, it’s essential. Complex businesses need as much of a plug and play network administration as possible, which automatically recognises mac addresses and associates them with the correct extension and corresponding configuration. This is another aspect of SIP phone functionality that used to be considered cutting edge but is now required as standard.

You might be able to get by without a provisioning system if you’ve got just a handful of phones, but if you’re rolling out anything larger than that, it’s a must-have.”

Steve Harris, Managing Director of VCOMM notes that each platform is different and believes the ease is usually linked directly to the platform vendor’s attitude to open standards and whether or not they are trying to mandate their own headsets. “There are some real differentiators now for Polycom and Yealink in working with Broadsoft with the support of their UCOne, IM&P feature set and similarly the work undertaken by Digium in delivering SIP handsets specifically for the Asterisk community.

What do the hosted telephony providers prefer to recommend their resellers use?

Garland at ProVu says that generally speaking Service providers like to work with a small number of manufacturers as this cuts down on the interoperability testing and support burden. “The smaller the range of handsets an SP has to support the easier their support issues become.”

Meanwhile Nimans Paul Burn says that each hosted provider will have recommended types of handsets because they are the ones they will have done their feature transfer testing on.

“There might be two or three brands they work with. One or two specific manufacturers have a large chunk of the market.  We see SIP end points being split into two distinctive camps. If it’s a system sale then end points tend to be from that particular manufacturer, whilst in the hosted arena there’s a lot more choice.

“Brands that have traditionally had a lot of market share, due to their good hardware, software and provisioning systems include Yealink, Snom, Aastra, Polycom, Cisco and Grandstream,’ says Alexis Argent.

“Of those, I’d argue Snom has been technically the best for a long time, although Yealink is now not far behind, and Grandstream is a good choice for anyone with more of a constrained budget.

What’s important are factors like build quality, ergonomics and how sophisticated and stable the software is. We are talking about business equipment and software here, so reliability and configurability are crucial.”

Will PBX vendors support third party endpoints?

Richard Bennett, “When we launched Avaya Aura Session Manager, our objective was to leverage the customers’ existing PBX infrastructure. The goal is to help ensure an evolutionary path forward for the customer and to protect that customer’s investment in their Avaya systems and software.

The Session Manager’s SIP based routing provides more centralised control capabilities and significant improvements in scale and redundancy. This enables more cost effective and larger distributed enterprise deployments. As well as lowering the total cost of ownership, it is also completely possible to connect it with third-party equipment and end points.

ProVu’s Darren Garland says this is an interesting area.

“PBX vendors tend to come at this from two differing standpoints; one is where the vendors do not supply proprietary handsets and one where they do. Those that supply their own handsets have no vested interest in working with open standard SIP vendors so generally make it difficult and expensive for them to deploy their handsets. Therefore by definition the majority of SIP phones deployed on PBXs tend to get deployed on more open standard PBXs such as SARK, Ipcortex, 3CX etc.

Obviously the SIP handsets still need to be interoperability tested but there tends to be more of a symbiotic relationship between PBX vendor and SIP handset vendor which makes the whole process much more achievable.”

Paul Burn at Nimans says manufacturers want resellers to take the least risky option and that’s by buying their end points for their system.

“It makes so much sense to do that. There’s little difference in price. Where it’s a traditional vendor they prefer you to put their own end points in because there should be more control, consistency and better technical support.  There’s no major cost differential to put a reseller off.

On the other hand Alexis Argent says this is definitely the way it’s going.

“Contrary to popular belief, Asterisk - the open source PBX from Digium, has totally changed the PBX landscape, as it interoperates with virtually every single SIP end point out there. I think Asterisk is also now the most popular IPPBX and has eroded the market position of the traditional ‘big boys’ because it’s been IP endpoint agnostic from the start.

Traditional PBX vendors have had to up their game, and provide support for more third party products, rather than the previous approach which favoured proprietary locked down systems.”

Harris at VCOMM believes the answer to the question ultimately depends on the attitude and commercial dependence of the platform vendor on handset sales.

“All the hosted telephony platforms are in the main handset agnostic, using standard protocols and their ‘open’ approach and partnerships with phone vendors creates a strong ecosystem. Hosted PBX vendors also provide a range of documentation to enable the configuration of 3rd party IP Phones against their platform.”

Dr Stuart Marsden, Managing Director MyPhones.com says that SIP phones can make or break your hosted service.

“They’re more than just a device for making and receiving calls, they are an important interface with the system that allows users to define and configure their personal preferences, and make the most of the telephone service they are paying for.

With 21,000 SIP devices provisioned on MyPhones.com hosted telephony systems, we need phones that we can provision quickly and easily, and update remotely and reliably.

We are prepared to put time and effort into this. It can take a year of testing and tweaking before we are completely happy with the phone firmware. So, we look for manufacturers who are as interested in and care about our systems as much as we do.

We particularly recommend CISCO IP phones, which we supply at cost as part of our Altos system, and Panasonic DECT phones. We are also working with Gigaset and Yealink.

Best of Both Worlds?

Gavin Sweet, Director at Skyrack Telecom tells us that the most exciting entrant to the market are the new wireless desktop phones such as the Tecdesk range from Santok, which are GSM/SIM based SIP phones – in effect desk phones but using mobile handset technology.

“These devices fully support the ground-breaking Mobile-X SIM and mobile PBX service allowing a ‘wires-free PBX to be deployed very very easily.”

Sweet says that Cisco and Polycom remain strong brands in the market, with good performance and solid interoperability with Broadsoft and our other PBX and SIP platforms.

“Yealink devices are now a realistic alternative and are very well received by customers. We find Yealink devices to be well-supported and easy to use and set up, with good manufacturer and distributor support. Gigaset remain our strongest recommendation for cost effective and easy to deploy DECT phones. As typical users become more used to ‘apps’ soft client SIP phones are also a more acceptable component of many solutions, and softwares such as Broadtouch for Broadsoft and Bria are really quite popular particularly as ‘phone backup’ options for PC or Smartphone.

In all cases, proper interop and zero touch set up enabled by platform device management capabilities are absolutely fundamental to quality of service delivery and reduced support burden.”

The big advantage of SIP for customers is the ability to re-use different handsets on different systems. They also benefit from a wider range of handsets from manufacturers who support the host platforms signalling. In our example as a BroadSoft platform owner, we have Polycom, Cisco and Yealink handsets that provide very tight integration with BroadSoft and consequently, a feature-rich experience for the user.

The reality is that we live in a proprietary world and wherever you have ‘smarts’ you have proprietary messaging.

Ed Says…

Make sure any phone you try and install on a platform is interoperability tested and approved – why take the chance? IP/SIP phones were meant to usher in more choice for the user but it’s the same old vendor branded models that get installed on the PBX. There’s more hope for choice on a cloud/hosted solution.