Enterprises have been reluctant to support unified communications (UC) standards, but user demand for extranet...
connectivity and access to UC applications beyond the firewall is prompting renewed interest in UC standards.
Standards in the unified communications and IP telephony world are a bit like exercising and eating right—everyone agrees they are a good thing, but in reality, few enforce their use. Nemertes' research shows that the vast majority of UC implementations pay lip service to standards; they require support for the Session Initiation Protocol (SIP) for system-to-system interconnectivity, but largely rely on proprietary protocols such as Cisco's Skinny Call Control Protocol (SCCP), Microsoft RTAudio/RTVideo or other proprietary protocols for endpoint applications.
However, UC standards are getting a new look among UC architects thanks to increasing user demand for extranet connectivity. Seventy-four percent of participants in the upcoming Nemertes 2011-2012 Communications and Computing Benchmark are deploying, planning to deploy or evaluating extranet federation for UC applications including IM, presence, voice and video. Crossing the chasm from internal-only UC applications to enabling connectivity across company boundaries, and often to disparate systems, requires a standard means of communication.
Most IT architects are pretty familiar with SIP, but SIP isn't the be-all, end-all for UC interoperability. SIP merely defines a signaling standard; negotiation of actual codecs, security/encryption and management still requires underlying interoperable standards such as H.264 for video encapsulation or G.711 for audio.
In addition to SIP and the underlying codecs, IT architects should familiarize themselves with several other UC standards as they extend UC applications beyond the firewall.
Extensible Messaging and Presence Protocol (XMPP)
XMPP is the granddaddy of all UC protocols, developed in support of the Jabber open source instant messaging project many years ago. XMPP was almost left for dead as a result of the growth of SIP and the complementary SIP for Instant Messaging and Presence Leveraging Extensions (SIMPLE) protocol embraced by Microsoft and others, but XMPP has seen a resurgence thanks initially to support from Google and Cisco's acquisition of Jabber.
Now other vendors are growing XMPP support thanks to the simplicity and extensibility of XML-based development. Even Skype recently added XMPP support to its current Windows client in beta testing. Look at XMPP both for interoperability and as a way to extend messaging protocols into other business applications (e.g., custom alerting services).
The SIP Forum has developed SIPconnect to enable SIP trunking service providers and IP telephony system vendors to standardize interconnections, hopefully avoiding interoperability problems that have plagued many early SIP trunking implementations. IT buyers should mandate SIPconnect 1.1 support in any system they purchase. Pay attention as well to the results of the SIP Forum's SIPit interoperability events in which vendors and service providers test interoperability for SIP-based services including voice and video.
Telepresence Interoperability Protocol (TIP)
Introduced by Cisco and now supported by Polycom and others, TIP is designed to standardize immersive telepresence interoperability across vendor platforms, accounting for features including directional audio and active speaker screen switching. The International Multimedia Telecommunications Consortium (IMTC) recently conducted a TIP interoperability test with systems from vendors including Cisco, Polycom, Radvision and Teliris. Evaluate TIP as part of your telepresence extranet plans.
Each of these standards will play a growing part in extranet federation plans. Talk with your vendors about their support plans and follow standards development efforts.
About the author: Irwin Lazar is the vice president for communications and collaboration research at Nemertes Research, where he develops and manages research projects, develops cost models, conducts seminars and advises clients. Lazar is responsible for benchmarking the adoption and use of emerging technologies in the enterprise in areas including VoIP, UC, video conferencing, social computing, collaboration and advanced network services.