CableLabs Revamps CMTS Testing Process

Looking to end a lengthy dry spell and to encourage cable modem termination system (CMTS) vendors to submit products for interoperability testing more frequently, Cable- Labs has overhauled its DOCSIS 3.0 qualification structure.

Pivoting away from an old, monolithic CMTS qualification process, the new, more flexible structure gives vendors the option of testing products in bite-sized, feature-focused pieces, something CableLabs now calls “test units.”

For example, if a manufacturer added upstream channel bonding or revised how IPv6 was being implemented, the company could enlist CableLabs to test against only those features, rather than having to run the CMTS against the full battery of tests.

In addition to defining independent test areas, the new plan also introduces the notion of “core” qualification testing that bundles together feature sets that define the baseline functions of a DOCSIS 3.0 CMTS.

The new way should also be lighter on vendor wallets, or at least allow them to get more bang for their buck, as the process is now rate-structured based on a specific number of test units (see table). And the amount vendors pay per test unit will drop if they decide to purchase test units in bulk.

Vendors can also buy those test units up front and spread them out as needed. Test unit purchases are valid for up to a year, according to CableLabs. Previously, CMTS qualification testing set a vendor back about $175,000.

CableLabs said it initiated the changes based on feedback from manufacturers that complained the old, more rigid process was financially burdensome and technically problematic because it required them to test their CMTSs against the full specs every time out, whether it involved a brand new product or some software tweaks made to existing CMTS models.

In some ways, the new process is a more refined version of a tiered testing scheme CableLabs used during the early days of DOCSIS 3.0, which represented a quantum leap in terms of features and functionality when compared to DOCSIS 2.0. Back then, CMTS makers could shoot for “Bronze” qualification, which covered downstream channel bonding and IPv6; “Silver,” which added upstream channel bonding and advanced encryption; or “Full” 3.0 qualification. CableLabs phased out that tiered testing program in 2009.

CableLabs hopes the revamped process will result in more submissions as vendors update and enhance their DOCSIS CMTS products.

And it should bring more dollars in the door at CableLabs, which has not awarded a CMTS qualification stamp in years. In fact, the last time a vendor submitted a CMTS and obtained a qualification stamp was in December 2008, when Casa Systems secured the “Full” DOCSIS 3.0 stamp for its C10200 chassis. Casa remains the only CMTS vendor to obtain 3.0 CMTS qualification beyond the original Bronze level.

If the new system works out, CableLabs said it expects to use it for DOCSIS 3.1, a next-gen spec that is aiming for capacities of 10 Gigabits per second downstream and up to 2 Gbps upstream. CableLabs released the DOCSIS 3.1 product specs last fall, and the initial 3.1-pointing CMTSs and cable modems are expected to show up later in 2014.