• IMS, SDP, NGNs...

----- Original Message -----
From: José de Ribamar Smolka Ramos
To: wirelessbr@yahoogrupos.com.br
Sent: Wednesday, April 25, 2007 9:01 AM
Subject: [wireless.br] IMS, SDP, NGNs... (publicado no Heavy Reading)
http://www.heavyreading.com/

IMS: Enough About the Rabbits Already!
Joe McGarvey, Senior Analyst, Heavy Reading

Though Steinbeck has fallen out of favor in the last few decades – nobody likes to be reminded of dustbowls and depressions, go figure – the short novel Of Mice and Men was still a staple of the English curriculum way back when I was in junior high. And thanks to Hollywood and Broadway churning out dozens of versions of the tale over the years, the phrase "Tell me about the rabbits, George," remains familiar to a large cross-section of the population today.

As a quick reminder, though, Of Mice and Men is mostly about (putting aside the social commentary about life in the 1930s) the relationship between two itinerant farm workers – Lenny and George – in pursuit of owning their own place. The "rabbits" line comes from George's practice of pacifying the dim-witted Lenny with rose-colored descriptions of their future homestead, littered with gaggles of fuzzy bunnies for Lenny to pet.

Appraising the current status of the adoption of next-generation technology, it's almost impossible not to draw the analogy that network equipment providers have been playing George to the service providers' Lenny for the past couple of years.

Nearly all of the talk around next-generation networks (NGNs), IP Multimedia Subsystem (IMS) and service delivery platforms (SDPs) has to this point been about the destination. For the most part, 2005 and 2006 were one long, continuous "tell-me-about-the-rabbits" routine, as carriers and large service providers sought assurances about the Shangri-La that awaits them after their move to NGN. "Tell me about IMS, Ericsson. Will there be lots of new services to sell, Alcatel-Lucent? Can I save lots of money by moving to a horizontal architecture, Siemens? Will there be plenty of fixed-mobile convergence, Nokia? Will we be able to live offa the fatta the LAN?"

Network equipment providers, for their part, have been more than happy to assume the George role. Of the hundreds of presentations and pitches delivered on NGN or IMS over the past couple of years, nearly all have focused on the destination rather than the journey. Descriptions of finely tuned networks, capable of turning out new applications in a matter of days and delivering customized services that eliminate the boundaries between fixed and mobile or work and leisure, are as common as a crooked politician, but it would take a microscope of considerable power to find a honest evaluation of how service providers are actually going to reach that land of milk and honey.

Nearly a quarter into 2007, it seems carriers and service providers have finally grown weary of all this talk of rabbits. The noticeable deflation of IMS hype in the latter portion of 2006 can be directly attributed to service providers beginning to turn a skeptical ear to the saccharine diatribes of their parts suppliers. Even children will lose interest in bedtime stories if every fairy tale they hear ends and begins with "…and they lived happily ever after."

Carriers, it appears, are finally waking up to the fact that they'll never enter that service delivery Promised Land until equipment makers stop skipping to the denouement and start fleshing out the early chapters of their transition stories. Even a superficial inspection of the situation reveals that the NGN roadmap has three major missing pieces that, unless found, will prevent service providers from transforming their networks into the subscriber-centric vessels that IMS and SDPs promise.

Backward Compatibility: Although this is Telecom 101, the folks creating the standards have spent nearly all of their efforts making sure that the dozens of functional elements in the IMS specification can talk to each other, without giving much more than a passing thought to making sure these elements work with the existing service and application environments. Without backward compatibility, IMS is just another stovepipe in a carrier's vertically organized infrastructure, and its adoption means a continuation of the status quo, rather than a reversal.

Service Orchestration: The irony about service orchestration is that the name of the mechanism that has come to represent the functionality – the Service Capabilities Interaction Manager (SCIM) – is almost as long as the technical prose dedicated to the subject in the 3GPP specification. It's not surprising that the standards bodies have left this utterly critical IMS component out of the specification: The process of coordinating the actions of multiple application servers, both in and out of a Session Initiation Protocol (SIP) environment, is not a trivial task, and is most likely best left to the efforts of individual equipment suppliers – which unfortunately have been slow to seize on anything resembling a definitive solution to this problem.

Non-IMS Traffic: To give proper credit where it's due, as early as 2005 some equipment makers were quick to recognize that a SIP-only service delivery architecture suffered severely from the fact that SIP makes up only a small percentage of the IP traffic that currently traverses service provider networks. While most equipment vendors have now addressed this issue by positioning IMS as a subset of a larger, more encompassing service delivery environment, work still needs to be done before carriers can fully integrate all of their services (voice, video, IPTV, mobile) into a master delivery system that puts all traffic types under one thumb.

Only an honest and realistic account of the current status of these roadblocks will get the NGN movement back on track. The network equipment providers that make the rabbits-to-reality transition and start to tackle these problems head-on will be the ones that win the long-term loyalty of carriers and service providers. Those that continue to fast-forward past these glaring obstacles should prepare for an eventual customer backlash by familiarizing themselves with another Steinbeck novel: The Grapes of Wrath.

J. R. Smolka