Messaging vendors rally around SIMPLE protocol
An emerging communications protocol called SIMPLE is the front-runner to become the standard method for sharing online presence information and instant messages across the Internet, thanks to backing from market leaders AOL Time Warner and Microsoft.
Having the marketplace agree on the telephony-oriented SIMPLE protocol will encourage corporate use of instant messaging, supporters say. Industry use of instant messaging has been hampered by interoperability issues.
"The fact that AOL and Microsoft are moving in the same direction is good for everybody," says Neil Starkey, CTO at Lotus, the leading provider of corporate instant messaging applications with its SameTime software.
Starkey says most SameTime users support instant messaging internally for customer service and call centers. Once an industry standard is chosen, these companies can extend online presence and chat applications outside their networks to customers, suppliers and partners over the Internet.
"It all depends on getting an open standard in place and making sure that [the standard is] commercially viable," Starkey says.
The IETF is developing SIMPLE, which stands for SIP for Instant Messaging and Presence Leveraging Extensions. SIMPLE is based on the Session Initiation Protocol, a signaling protocol used to establish Internet telephone calls, multimedia conferences, chat sessions and interactive communications.
SIMPLE is one of three approaches to instant messaging proposed to the IETF, which has been struggling to reach consensus in this area for several years. The alternatives - Presence and Instant Messaging, and Instant Messaging Exchange Protocol - have fewer and less visible supporters than SIMPLE.
"SIMPLE is the direction the whole industry is moving toward for a standard-based instant messaging solution," says Jonathan Rosenberg, one of the authors of SIMPLE and the chief scientist at Dynamicsoft, which sells a SIMPLE-based software developers kit to service providers. "The winner is obvious."
AOL's recent announcement that it would use SIMPLE to open up its instant messaging system to other service providers came as a surprise to the IETF, which has seen little participation by AOL in the SIMPLE development process. Similarly, Microsoft plans to support SIMPLE in its MSN Messenger and Windows XP operating system, due out in September.
Taken together, the AOL and Microsoft announcements make it very difficult for an alternative protocol to emerge as the open standard for instant messaging.
"The AOL announcement, together with the inclusion in Windows XP, provides credibility and numbers," says Henning Schulzrinne, another SIMPLE author and an associate professor of computer science at Columbia University. "Practically speaking, SIMPLE becomes the de facto standard."
The market momentum for SIMPLE is driven by the view that instant messaging will not be an isolated application, where end users can see when others are online and initiate spontaneous text-based chats. Instead, SIMPLE advocates say presence and instant messaging will become part of a broader suite of integrated communications services that includes telephone calls, voice mail and Web conferencing.
For example, with SIMPLE, an end user could arrange a telephone call with another person when that person is off the phone.
"This integration between presence, instant messaging and traditional telephone communications is the single-largest reason why it makes sense for an enterprise to build a SIP-based architecture," Schulzrinne says. "Presence beats call waiting, and instant messages can work in conjunction with a phone call."
The SIMPLE working group will meet this week in London to debate a few remaining technical issues, including how to set up communications for large messages and multimedia, and how users will authorize the release of their presence information to other subscribers.
Members of the SIMPLE working group hope to finalize the protocol this fall and submit it to the IETF leadership for approval as a standards-track document before year's end.
Meanwhile, the IETF also is wrapping up its work on a common message format that can be used to ensure communications between applications based on SIMPLE and alternative protocols.
"There is still value in having the common format because not all systems have gone with the SIP/SIMPLE approach," says Leslie Daigle, co-chair of the IETF's Instant Messaging and Presence Protocol working group. "Indeed, there are other systems out there today."
Lotus' SameTime uses proprietary instant messaging technology, but company officials are committed to supporting industry standards. Two concerns that Lotus has about SIMPLE are how it handles security between service provider networks and how the privacy of presence information is protected.
"The security aspects are extremely important to enterprises. We need to make sure those are properly dealt with," Starkey says. "We also need to have user-level control so that presence information is only available to certain people."