Open Mic: DOCSIS 3.0: Under new management

Fri, 07/31/2009 - 8:15pm
Jason Schnitzer, Founder and principal of Applied Broadband

Where IPDR shines is in its capability to provide timely visibility
into discrete subscriber and service-level events.

Deployments of the latest and greatest DOCSIS version are well under way as subscribers enjoy an enhanced service experience thanks to the marvels of channel bonding.

Jason SchnitzerThough the DOCSIS 3.0 (D3) mantra is speed, this feature alone doesn’t capture the complete breadth of the protocol. In addition to speed, D3 also offers a rich suite of new management tools designed to help service providers enhance the subscriber experience and optimize resources.

The arrival of these new management tools is well-timed. With enhanced services and higher speeds, the need for effective subscriber and service management is greater than ever.

Coincidence or otherwise, the introduction of D3 has occurred right at a broadband tipping point. That is, we’re moving from the mindset of “the network is the service” to a new standard in which services and the network are decoupled.

Before, the voice network delivered voice, the data network provided data and the video network supported, well, video. We’re now looking at these services in a different way – not just as enhancements, but, rather, new ways that mash up features from all three, resulting in something new altogether. As a result, though D3 enables these new service opportunities, it also brings a new level of service management complexity.

Fortunately, the industry recognized the requirements for enhanced management tools in D3 and worked to embed new features directly into the protocol. Included in these tools is IP Detail Record (IPDR), which serves to address the information scalability and complexity problem of D3 service and subscriber management.

Thought of one way, IPDR is a better network management mousetrap. Where IPDR shines is in its capability to provide timely visibility into discrete subscriber and service-level events, such as network usage counters and service performance measurements.

In the DOCSIS network, subscriber services are delivered in individual service flows. These service flows are configured by the provider to carry specific types of Internet applications with different levels of quality of service. QoS-sensitive IP applications such as voice or video are “classified” into a service flow designed to enhance performance. All other IP applications that do not require access network QoS are classified into a best-effort service flow.

The traffic for each service flow in a D3 network is carefully counted and recorded. In addition, service quality metrics are calculated for the life of the flow. IPDR is used to prepare and transmit this information to the service provider’s management systems.

IPDR-based visibility into D3 subscriber service flows follows the traditional metered utility model for critical services, such as power and water. That is, it provides a way for the provider to accurately quantify subscriber usage by how much capacity was used, rather than precisely what it was used for.

When applied to usage monitoring, IPDR offers advantages over the deep packet inspection (DPI) approach by preserving subscriber privacy. Specifically, because IPDR counts traffic on the service flow level, it requires inspection of each packet in order to report per-subscriber traffic volumes. In this way, IPDR offers promise as a privacy- and network neutrality-friendly technology.

It’s worth noting that the use cases for IPDR in D3 service management extend beyond service flow monitoring. IPDR in D3 is also used to monitor fault and performance events for all cable modem-enabled subscriber devices.

Beyond applications in DOCSIS service management, the cable community is investigating IPDR as a candidate for use in other initiatives, such as addressable advertising and tru2way.

D3 is one of the most complex and feature-rich protocols the broadband industry has seen yet. However, delivering on the promise of D3 requires more than just a network upgrade; it also requires a big transition in provider mindset – from managing the network to managing the service.

It remains to be seen what service providers will do to make the most of this new IPDR toolkit when managing their D3 services, but it’s a promising new technology now there for them to use.


Next month, R.L. Drake President and CEO Jeff Huppertz will write
about business services, including the growing market for cable
operators to deliver HDTV services to the hospitality sector.

If you've got an idea for a column, send it to


Share This Story

You may login with either your assigned username or your e-mail address.
The password field is case sensitive.