Migrating Your Network to DOCSIS 3.0

The road to DOCSIS 3.0 has both speed bumps and shortcuts, but either way you turn, cable operators need to get in the race.

Cisco Systems and Communications Technology sponsored and hosted, respectively, a webcast last week on the migration path to DOCSIS 3.0.

Cisco Senior Director of Product Marketing John Mattson started the webcast by outlining the main components of DOCSIS 3.0, which include downstream and upstream channel bonding, which include a minimum of four channels for both, IPv6, multicast and AES (advanced encryption standard) encryption.

"These are the ones that are flying the highest," Mattson said. "These are the ones that we’re hearing about the most from our customers."

Mattson said cable operators would like to offer speeds from 50 Mbps to 100 Mbps into the home, but because of companies such as YouTube, customers are launching more services out of their homes, thus increasing demand for greater upstream speeds. While Verizon‘s FiOS fiber-based solution can offer symmetrical service to its customers, Mattson said it can’t match cable’s potential for the downstream speeds, but cable needs to be aware of increasing its upstream speeds as well so they won’t be "the chink in the armor." IPv6 Mattson said that while IPv6 won’t offer any competitive advantages per se for cable, the new addresses will give cable operators some operational efficiencies and make the IP networks more scalable.

Saifur Rahman, senior manager, advanced engineering, for Comcast, said IPv6 is a priority for Comcast. The new addresses are needed internally to manage set-top boxes, EMTAs and cable modems.

"IPv6 is clearly the way to manage internal devices," Rahman said. "We need IPv6 so global NOCs can see each subscriber. IP touches almost all of the devices, so we look at this as a long term project."

Rahman said it’s not just the larger MSOs that need IPv6; cable operators with a footprint as small as 3 million will also benefit from its implementation. On the customer side, IPv6 will break a potential logjam of addresses for all of the new devices that consumers are clamoring for.

For the transition to IPv6, Rahman suggested that cable operators audit all of their systems to find what could break, work with vendors to develop a roadmap, and ensure that all new elements have IPv6 as a requirement.

In contrast to Comcast, Cox‘s Ben Bekele, senior DOCSIS engineer, said IPv6 wasn’t as big a priority for his company because of how Cox has its systems architected. Benefits of bonding Rahman said bonding channels has several drivers. As customers move toward Internet applications that include both video and audio, cable operators will need to increase their capacities to enable future services and applications.

On the commercial side, bonding will help deliver T-1 or E-1 services and offer data backup, committed information rates, and thin client applications to small and medium businesses.

Some of the benefits of channel bonding include the ability to serve 100 Mbps in both directions while still leaving room for HD and SD TV channel lineups.

Rahman also said cable operators don’t need to wait for the full-blown version of DOCSIS 3.0 to start down the migration pathway. They can add more downstream DOCSIS RF channels and downstream load balancing instead of node splitting and field trial pre-DOCSIS 3.0 solutions until the full solution is available. While downstream bonding can currently be accomplished through software, upstream bonding requires hardware upgrades, but Rahman said to plan ahead so that "you don’t rip out CMTSs twice." M-CMTS deployments Cisco’s Mattson said that while DOCSIS 3.0 and modular CMTSs (M-CMTSs) were developed in parallel by CableLabs, "there’s some confusion on how they go together." Mattson said that while the two are complimentary, DOCSIS 3.0 is about more throughput and enabling new services, while M-CMTS technology is focused on scalability and reduced costs.

Bekele said Cox is looking at M-CMTS because it’s key to increasing downstream capacity, as well as increasing speeds to existing DOCSIS 1.0 and 2.0 modems.

"Modular CMTS gives you the ability to offer more downstream capacity without paying a lot up front for it," Bekele said. Delivery date for DOCSIS 3.0 Mattson said DOCSIS 3.0’s delivery date has been delayed because some vendors had to make some changes to align with DOCSIS 3.0, while other vendors are still working on IPv6 and multicast products.

"It’s taken a little longer for the vendors," Mattson said. "On the CM side, we need new silicon to allow the vendors to complete development, but sometimes they need to spin it several times, and then vendors needs about a year to develop with it."

Mattson said the cable industry should start seeing DOCSIS 3.0 products some time next year.

For the on-demand version of the webcast "Migrating Your Network Performance to DOCSIS 3.0," go to www.cable360.net/ct. Registration is required for the webcast. – Mike Robuck