eDocsis: The final frontier
PHOTO BY BOB SULLIVAN
propagation of embedded cable modem technology
By Jeff Baumgartner, Assistant Editor
The DOCSIS cable modem invasion is on.
Ready or not, the technology is starting to spread itself into a wide range of devices such as multimedia terminal adapters, set-top boxes and residential gateways. Not before too long, it might not be a stretch to suggest that core DOCSIS technology could also weave its way into game consoles, refrigerators and other everyday household appliances.
Instead of playing a starring role, as it does in stand-alone cable modems, DOCSIS in an "embedded" environment would provide a subordinate function at the core chip level to the host device. And, rather than leveraging a home networking protocol, an embedded DOCSIS device would feed directly into a cable network's DOCSIS channel.
This emerging–and apparently inevitable–embedded DOCSIS market could also present complications that could affect how CableLabs tests and certifies DOCSIS equipment, how cable operators monitor embedded DOCSIS devices, and how those devices handle software changes without falling prey to security breaches and damaging viruses.
CableLabs has already detected this trend, and has proposed a new initiative to deal with it before potential problems become here-and-now menaces. Hoisting the flag of this new initiative, dubbed "eDOCSIS," is Rouzbeh Yassini, senior executive consultant to CableLabs and CEO of YAS Broadband Ventures LLC–and the man more commonly known in industry circles as the "father" of the cable modem.
In addition to taming potential bugbears that could affect certification, network monitoring and whatnot, CableLabs is also forging eDOCSIS to further drive down a cable modem's operational and capital costs.
"It's getting cost-effective to put that modem into things like residential gateways and set-top boxes…anything that needs to do IP over cable," says Doug Jones, chief architect at YAS Broadband Ventures.
Embedded DOCSIS devices aside, stand-alone unit prices have dropped sharply over the last year, piercing what once was considered an ambitious milestone of $100 per unit.
And that's not just for cable operators. Consumers, if they spend more than two minutes researching modems on the Web, can find some pretty good deals. A recent check on Buy.com revealed a Linksys "Etherfast" cable modem for $79.64 and a model from D-Link for $77.01.
So, where do we go from here?
Yassini says the future of cable's key data specification isn't limited to a stand-alone cable modem that merely plugs into a PC and pumps data, but plunges much deeper, touching a network's management, security and provisioning pieces.
eDOCSIS, he says, will help MSOs get there, as it marks "the last frontier for DOCSIS…the final chapter to what DOCSIS is going to end up to be."
If all goes according to plan, the form factors and costs of DOCSIS ultimately could end up mirroring current Ethernet implementation. Once a rather clunky and expensive stand-alone device that had to undergo rigorous testing, Ethernet today is embedded and supported in myriad devices, virtually transparent to the end user.eDOCSIS: STEP-BY-STEP
Presently, eDOCSIS is at its second stage of development: the specification phase. CableLabs made it past the first step–the proposal phase–when the DOCSIS board sanctioned the project on August 14.
The eDOCSIS specification will focus on the interface between the embedded modem and the host device. The intent is to maintain the integrity of several key cable operator policy points within the modem. The specification effort will begin this fall.
But that's just the beginning. Several steps remain in eDOCSIS' evolution. Following the creation and approval of a specification, the project will shift into interoperability testing, followed by certification testing, and ultimately, to shipping of eDOCSIS-certified products.
The length of time it will take for eDOCSIS to complete all of those milestones is still unknown, but, if history is any indication, it could happen quickly. Each project in the DOCSIS chain so far has moved faster than its predecessor in getting from the certification to the shipment phase.
With the go-ahead from the board secured, CableLabs could complete the specification phase sometime in 2003, Jones estimates.PREPPING A NEW PARADIGM
Before eDOCSIS makes it to the certification testing stage, CableLabs also will be busy devising ways to make the process much cleaner and less costly than it is for vendors today.
In its current form, DOCSIS testing requires manufacturers to muddle through the process each and every time they make a software change to an embedded DOCSIS device. At $95,000 a shot, that's a pretty expensive proposition.
Costs, of course, represent just one challenge that lies ahead for embedded DOCSIS. CableLabs also has to contemplate how to considerably pare down the testing logistics and the resources required to carry it out.
"I don't think we can get there without some changes to how we manage DOCSIS in the embedded device," says Bruce McClelland, vice president of engineering for Arris Broadband.
CableLabs began dealing with that situation in August, when it announced plans to integrate its test program and lower certification fees by as much as 60 percent (see sidebar at right).
CableLabs is pondering ways to simplify the certification testing process for embedded DOCSIS devices.
Yassini notes that certification testing has followed an evolutionary path that starts with manual testing. From there, it moves to automated testing, third-party testing and self-testing (or an auto-certification "honor system"), and then finally to testing on the manufacturing plant floor, because the spec is so taut that testing can be built into the manufacturing process.
CableLabs presently is at the automated test phase. Back in the early part of 2001, CableLabs also considered, but later scuttled, a plan to involve third-party testers. Though nothing has been decided on this issue yet, Yassini envisions a day in which DOCSIS certification testing could completely "leapfrog" the third-party phase and enter an era of vendor self-testing or an honor system.
By design, however, the certification process is streamlining and evolving gradually on its own, thanks in part to the fact that new DOCSIS modems require fewer chipsets than their forefathers. DOCSIS modems, which required up to four separate chips in 1999, have collapsed all of those functions onto one chip, saving operational and capital expenses along the way.
Streamlining the testing and certification process will also grow in importance as unit prices continue to decline. "It makes sense to spend $2 or $3 on testing when the price of a unit is $100 or more," Yassini says. "But, when prices fall below $50, you also have to adjust that, because the biggest percentage of the cost comes from the testing."SCALING UP
Although a new eDOCSIS specification and a slimmed down certification process could usher in legions of products through CableLabs, Yassini believes the testing process is flexible enough to achieve that scale.
Under CableLabs' test philosophy, a new DOCSIS test plan isn't written for every kind of box–stand-alone modem, set-top box, washing machine or otherwise–that flows through its hallowed halls. Instead, CableLabs leverages a modular Test Execution Plan (TEP) that tests against specific functions. For example, DOCSIS 1.0 products face 29 TEPs, DOCSIS 1.1 modems encounter 58 TEPs and MTAs deal with about 75 tests.
Of the possible eDOCSIS scenarios, CableLabs is currently weighing how to test a cable modem on a "daughter" card or as a motherboard element.BATTENING DOWN THE HATCHES
The Computer-Controlled Cable Modem (CCCM), proposed by Intel Corp. in 1998, is a single-chip DOCSIS modem designed to reside within a personal computer and share some memory and processing functions with the host, essentially creating the first cable-ready PC for consumers. eDOCSIS, taking matters several steps further, is a broader model that injects DOCSIS into an almost unlimited number of host devices.
Although divvying up those resources offers high levels of efficiency and better cost curves, the practice does raise some potential security risks.
"Sharing is good, but it's got to be safe sharing," Yassini says, adding that eDOCSIS devices would embody security measures similar to their stand-alone cousins. Without the proper protections, however, an embedded DOCSIS device could be subject to "a rogue application or a virus," Jones warns.
CableLabs covers those security issues in its interim CCCM specification, but more work must be done for eDOCSIS implementations.
Jones notes that one provision under consideration calls for security to be done via hardware, creating a self-contained system that shields against viruses and other possible attacks. CableLabs is also looking into the virtues of a VLSI (very large-scale integration) implementation to ensure that other functions of the host device don't impact DOCSIS. Worldwide nano-level silicon technology will be the key to executing on eDOCSIS, he adds.eDOCSIS APPS
While the idea of putting DOCSIS into refrigerators and washing machines might get people's interest, "that's not really what anybody's talking about," says McClelland. "But there are a plethora of potential devices that could actually embed DOCSIS that are very practical."
Those examples, he says, include residential gateways, devices that distribute video to multiple screens in the home; and home automation gear, which don't typically absorb much bandwidth, but could take advantage of DOCSIS' inherent always-on capabilities.
eDOCSIS' QoS capabilities, he adds, will help operators discover what those are, whether it's for some sort of video or audio application, interactive gaming or even teleconferencing.
Beyond set-tops, gateways and MTAs, "personally, I don't foresee there being a huge move toward arbitrary devices being brought into the network," Tausworthe says. "More importantly, I don't see the MSOs allowing that to happen. If they allow the services to grow without bound, they could reach capacity on their networks and not be able to manage it."
In addition to certification, eDOCSIS devices, because they house core cable modem technology, will also have to be provisioned and authenticated by the cable operator before they're allowed to run wild on a network.
BroadJump Inc. is one of those companies that makes software designed to simplify that process for stand-alone cable modems. "We are looking at that [embedded DOCSIS] area," says BroadJump Vice President of Business Development Hunt Norment. He adds that residential gateway vendors have already approached the company about creating such software, and that BroadJump is working with CableLabs to make it happen. "There's demand already for this," Norment says.