CableLabs Accelerates Docsis 3.0 Testing

Cable operators appear to be putting Docsis 3.0 deployments on a fast track after CableLabs unveiled a plan seeking to speed up the testing process for cable modems and headend gear based on a platform that promises to push Internet speeds well beyond 100 Mbit/s.

If all happens as anticipated, operators could begin to deploy Docsis 3.0-based services as early as the second quarter of 2008, according to cable engineers familiar with the effort. That's well ahead of earlier predicted timelines that saw Docsis 3.0 equipment reaching deployable levels by late 2008 or sometime in 2009.

The more ambitious plan will also give operators earlier access to the technologies and services required to stay competitive with telcos that are rapidly deploying fiber-to-the-home networks.

Under the accelerated test plan, vendors are expected to submit Docsis 3.0-based equipment to CableLabs as early as the fourth quarter of 2007. That would point everything to Certification Wave 57, now considered a "rallying point" for cable modem and cable modem termination system (CMTS) suppliers. If those manufacturers want to be considered for testing in Wave 57, they must submit products by the first week of October, according to a schedule posted on the CableLabs Website.

In the interim, the Louisville, Colo.-based cable R&D house will conduct Docsis 3.0 interoperability tests, with two to three slated for the rest of 2007, according to CableLabs chief technology officer Ralph Brown.

The new test plan gives CMTS vendors the most wiggle room in terms of the features they are expected to support in order to obtain a passing grade from CableLabs. It also lets them prioritize which features to support in the earlier phases of testing.

While modems will be required to reach a uniform level of certification to be considered compliant with Docsis 3.0, the new plan will allow CMTS vendors to phase in features under a tiered approach. Those three tiers are: "Bronze," "Silver," and "Full."

CableLabs officials declined to disclose the specific features that will be required for each phase, citing a non-disclosure agreement. Brown, however, did point to some core capabilities handled by Docsis 3.0, including channel bonding, IPv6, and advanced security. He also stressed that CMTS vendors, despite the tiered testing approach, will be expected to support the full 3.0 specs eventually.

"The CMTS is always more complicated," Brown says, noting that it usually takes CMTS vendors longer than their modem counterparts to implement all of the features of a specification.

"We're really trying to encourage the manufacturers to bring in product that they've developed…and to give them some recognition on where they are in the development process," Brown says. The tiered testing system for CMTSs will allow those vendors "to get in there early and often."

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Cable engineers familiar with the three CMTS test tiers say Bronze will include core elements such as downstream channel bonding and IPv6; Silver will likely add in upstream channel bonding and perhaps the Advanced Encryption System (AES); and Full will include everything else, including the spec's administrative and monitoring capabilities.

They also believe the new plan will help speed Docsis 3.0 deployments.

"We think [the accelerated test plan] is a very positive development," says John Mattson, director of CMTS products for Cisco Systems Inc. (Nasdaq: CSCO), which expects to submit its flagship CMTS, the uBR10012, for "Bronze" testing in Wave 56.

He says Cisco and other parties have long advised that it makes sense to divide the CMTS portion of Docsis 3.0 into sub-segments, considering the sheer size and features found in the full spec. This way, vendors can implement the "significant features of Docsis 3.0" without slowing down the overall process, Mattson notes.

For some cable operators, particularly those crossing swords with Verizon Communications Inc. (NYSE: VZ) and its fiber-fed FiOS service, the quicker Docsis 3.0 comes online the better. Verizon's high-end tier offers 30 Mbit/s downstream. Cable execs and other industry observers believe a 50-Mbit/s tier from the telco will soon follow.

A rapid move to Docsis 3.0 would enable cable operators to offer shared speeds that breach the magical 100-Mbit/s mark.

Some cable operators, particularly those in Asia, have already implemented pre-Docsis 3.0 technologies that bond multiple Docsis 2.0 downstreams. StarHub of Singapore, for example, has already deployed a pre-3.0 service across the board using Motorola gear. Jupiter Communications Inc. , the largest cable MSO in Japan, recently announced the deployment of a similar system using Arris Group Inc. (Nasdaq: ARRS)modems and CMTSs. (See Japanese MSO Moves 160 Mbit/s.)

The new test plan also puts to rest any lingering notion that North American cable operators would latch onto "Docsis 2.0b," an unofficial label (no longer used) that originated with a set-top chipset from Broadcom Corp. (Nasdaq: BRCM).

That chipset, which bonds up to three downstream channels but does not combine upstream channels, is linked to the coming Comcast Corp. (Nasdaq: CMCSA, CMCSK) RNG set-top family. An adapted version of the Broadcom chipset was considered as an interim step toward the full Docsis 3.0. Operators backed off on the idea when they determined that formal adoption of the 2.0b approach would slow down the development of Docsis 3.0 considerably.

The new CableLabs test plan will cover both the modem and the CMTS, rather than just the modem, as it was with 2.0b. Brown of CableLabs also confirmed that modem and CMTS vendors that submit products for Docsis 3.0 will need to bond a minimum of four channels.

"But the opportunity to do more than four is definitely there. We may see some bigger downstream channel bonding than the specs call for," Brown says.

CableLabs issued the Docsis 3.0 specifications in August 2006. (See CableLabs Issues DOCSIS 3.0 Spec.)

— Jeff Baumgartner, Site Editor, Cable Digital News