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Revisiting the SIP Endpoint

Today we hear a lot of talk about WebRTC and the disruptive potential of clientless communications. Before you jump to conclusions about this real-time communications protocol and its impact on phones, it's worth taking a look back at the last big endpoint revolution, which began just over a decade ago with the rise of SIP.

My first exposure to SIP endpoints was with Digium's Asterisk and Polycom's IP SoundPoint phones. Both companies were on the bleeding edge with these products, and contributed to the creation of the solid standard and interoperability that the industry enjoys today.

SIP is a runaway success. The protocol enjoys widespread support from carriers, hosted providers, and enterprise communication systems vendors. A third-party ecosystem provides a variety of products and services, including session border controllers, an array of endpoints, and specialized applications such as call recording and quality monitoring.

Even though SIP is radically different than the analog and digital technologies that it replaces, most of the legacy terminology persists. SIP trunks provide PSTN services and machine-to-machine connections. SIP lines are associated with endpoints such as phones.

SIP trunks get most of the spotlight. They are broadly supported, offer significant cost savings, and enable numerous benefits regarding quality and resilience. The only real issue to decide is when to deploy. SIP endpoints are not as universal as SIP trunks. Here confusion and ambiguity have kept universal adoption at bay.

Eye on the Endpoint
Endpoints have always been a big part of the communications system sale. Phones typically represent about half of the value of the sale, and informally create a longer-term commitment because upgrades are usually less expensive than replacements. This likely explains why most of the enterprise equipment vendors still push their own endpoints with varying degrees of SIP support.

Many industry watchers expected SIP to put an end to the use of proprietary endpoints, in that all SIP phones would offer near-identical experiences. But major UC equipment vendors, including Cisco, NEC, Mitel, Alcatel-Lucent Enterprise (ALE) , ShoreTel, and Unify, still lead with and typically sell (when a customer wants hard phones) their own branded endpoints. All of these companies support SIP, but their own endpoints offer tighter integration with their communications systems. Even if a vendor uses SIP as the underlying protocol, like-branded endpoints tend to provide simplified provisioning and advanced features.

Unfortunately, most SIP endpoint implementations are fairly limited. Many vendors position SIP as the new analog -- a lowest-common-denominator approach to providing dial tone for basic devices such as speaker-saucers and courtesy phones. In that regard, SIP endpoints are often a step backwards because digital handsets offer more advanced features, such as one-touch call record, speed-dial, busy-light indicators, and intercom, out of the box.

SIP itself doesn't have to be so limited. The SIP RFCs actually offer quite a bit of flexibility in implementation. This is a concurrent strength and weakness of SIP. It gives manufacturers and developers freedom to implement as desired, but also introduces limitations in interoperability.

Software-based vendors were quick to embrace SIP endpoints. Many skirt interoperability limitations by providing advanced features via a Web portal or client paired with a basic endpoint. Some provide richer features with SIP extensions and use of XML, which is also widely supported on SIP endpoints.

Evolving the Endpoint
Polycom has emerged as the market leader for SIP phones, enjoying close partnerships with many of the largest software-based communications vendors and providers, including Microsoft, BroadSoft, ThinkingPhones, and 8x8. And it continues to expand its support to more and more platforms (most recently ALE).

However, the market is highly competitive. The ecosystem of third-party SIP endpoint makers, which already includes Polycom, Mitel, Snom Technology, Apivio Systems, Spectralink, Yealink, and Grandstream Networks, continues to grow -- and innovate. Grandstream, for example, launched an Android-based SIP phone that supports Google Play applications while Apivio is launching a new Wi-Fi phone for the prosumer market.

Some vendors are adapting their approaches. Consider that Microsoft designed its own proprietary Lync phones that partners manufactured and distributed, which achieved tight integration with its UC platform including access to broader data such as Outlook calendar information. Snom became the first major SIP phone manufacturer to support SIP and Lync with a single phone. Polycom subsequently adopted a similar strategy with its VVX Series of SIP phones, which now delivers features that are not available with its Microsoft-developed CX Series phones.

For its part, Digium continues to support Polycom SIP phones with an impressive set of phone-top features on its Switchvox UC system, but also began offering its own SIP phones a few years ago. The Digium SIP phones offer a JavaScript application programming interface that lets programmers create phone-based apps. This enables Digium to offer encrypted provisioning and intuitive phone-top features such as one-touch recording and visual voicemail. Digium's application module simplifies installation, and increases its revenue and margin (for partners too) without increasing end-user prices.

SIP endpoints may not have lived up to all of the hype -- like the elimination of proprietary endpoints. But they have more or less lived up to reasonable expectations. SIP endpoints will generally work with most calling platforms, and their availability has led to a drop in endpoint cost. For companies that prefer softphones, third-party options such as CounterPath's Bria support SIP as well.

WebRTC will indeed revolutionize the industry in many regards, but it's safe to assume it won't mean the end of proprietary devices or applications. Like SIP, it's reasonable to expect vendors to borrow from and leverage the open technology into their own value-added solutions. At the same time, the open technology will deliver a way to quickly and inexpensively deliver a robust set of user features and capabilities.

Dave Michels is a Contributing Editor and Analyst at TalkingPointz.

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