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CMAP, CESAR, Whatever It Takes

June 2, 2011 - 1 Comment

By Mark Palazzo, VP/GM, Cable Access Business Unit, Cisco Systems

One of the more nuanced aspects of hard-core technological developments in the cable industry these recent months is the “CMAP v. CESAR” debate. Haven’t heard of it? Boiled way down, it’s a different set of viewpoints about the best way to migrate to a converged CMTS and universal edge QAM architecture, in conjunction with cable’s HFC (hybrid fiber-coax) plant migration.

To put this in historical context, cable operators “went digital” in phases. Digital video was first, followed by broadband data via cable modems, followed fairly shortly after by voice over IP. Operators use a form of modulation called “QAM” (quadrature amplitude modulation) to get video, data and voice signals over the plant to subscribing homes and businesses.

At issue was simple market timing: Digital video vendors built QAM products specifically to support video; broadband-side vendors built different QAM products, for high-speed data; and voice equipment vendors built QAM based TDM products for voice. The proprietary data and voice products where later replaced with the standardized DOCSIS CMTS platform.
As all three digital product lines are maturing, cable service providers are seeking ways to make their QAM gear more efficient – by creating a “one size fits all,”universal  QAM that can handle all three service types, while at the same time incorporating capabilities found in today’s CMTS’ and providing a more efficient use of bandwidth.

Comcast calls its version “CMAP” for “Converged Multiservice Access Platform.” Time Warner Cable calls its version “CESAR” (pronounced like the Roman leader and/or the salad). It stands for Converged Edge Services Access Router.

As a leading CMTS and QAM supplier, we get asked a lot what we think about the notion of supporting both, if that’s how it plays out. The easy and perhaps predictable answer is that we agree with both approaches.

There are a lot of similarities between the specifications, but let’s take a deeper look at the “alleged” differences – because in my view, while there are differences they’re complementary, not contradictory. For instance, while CESAR calls for smaller serving area groups, CMAP supports two SG sizes – one smaller, one larger. CMAP exists with and without encryption; CESAR excludes it. CESAR specifies an integrated platform; CMAP can be either modular or integrated. Lastly, CESAR specifies optional access network interfaces while CMAP continues to specify standard coax.

Speaking as a vendor – and as a guy who witnessed numerous technology transitions of the cable industry over the last 30 years – the differences between the two approaches don’t really detract from one another. They’re simply a testament as to how the cable industry has grown over time, the architectural decisions that were made years ago, and the impact of industry consolidation over the past decade.

So, we aren’t totally kidding with the title of this blog and the play on words taken from the famous “Mister Mom” line (“220, 221, whatever it takes!”). In a CMAP v. CESAR sense, it really is a case of whatever it takes.  Maybe a new name is appropriate – CARMASPEC– just a thought!

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  1. Nice summary!!

    I’d just like to point out that BOTH CESAR and CMAP include requirements for alternate access network technologies, both outlining EPON interfaces.

    So, like Mark well said, really no differences, but complemntary requirements.