Rather than drafting off of the Comcast Corp. (Nasdaq: CMCSA, CMCSK)-led Converged Multiservice Access Platform (CMAP) effort, Time Warner Cable Inc. (NYSE: TWC) is venturing out on its own as it pursues a new type of convergence edge device.

The TWC project appears to share much in common with CMAP. For starters, it will look for vendors to create a super-dense edge product that combines the functions of the edge QAM and the cable modem termination system (CMTS) and blend the more traditional cable RF world with IP.

"It's a home-grown equivalent to the CMAP," says an industry source familiar with both projects.

And it's got a different name. TW Cable is calling it the Converged Edge Services Access Router (CESAR).

The vision behind CESAR, says TWC Group VP of Broadband Engineering and Technology Howard Pfeffer, is to establish a "single edge device that allows us to deliver all of our services to the edge of our network, whether that's our traditional services or IP services." That same device would also let the MSO share resources among services as needed.

The MSO isn't sharing all the nitty-gritty technical details on what it has in mind, but it's calling on vendors to meet certain goals around density, throughput and performance. The operator is also looking for CESAR to help support commercial services.

"PON is something we're exploring as something we can integrate," says Ron da Silva, TWC's senior director of network engineering and architecture technology.

Integrated or modular?
While CMAP is specifying modular and integrated implementations for the architecture's Access Shelf (for the downstream and upstream PHY and MAC layer) and Packet Shelf (for packet processing) components, several industry sources believe TWC will likely stick with a highly integrated version of CESAR. The MSO says it hasn't formed a final opinion, but it does appear to be a bit wary of the potential pitfalls of more modular designs.

"We recognize that vendors may want to partner together to create a solution," da Silva says. "What we want to steer clear of is creating an interoperability nightmare for us where we have to be the integrator of a whole bunch of different components."

But it's still open to the idea if multiple vendors want to collaborate and present TWC with a pre-integrated package deal. "We honestly don't have a bias at this point," Pfeffer says, noting that the MSO intends to vet the strengths and weaknesses of every approach during its regular evaluation process.

TWC's decision to pursue its own project, despite its apparent similarities to CMAP, has caused a bit of confusion in the marketplace, leaving some vendors to wonder if they'll need to create entirely separate products for CMAP and CESAR.

But da Silva stresses that TWC has been holding discussions with MSOs and vendors about CESAR, and the situation is not all that extraordinary since MSOs typically have different product requirements for products like core routers and switches. To amplify that point, he says it's likely that Comcast's requirements for CMAP products will differ from the requirements of other MSOs that are contributing to that effort -- a group that includes Cox Communications Inc. , Cablevision Systems Corp. (NYSE: CVC) and Liberty Global Inc. (Nasdaq: LBTY), among others.

"If any operator created a document that reflected their needs with some other clever acronym, you'll see some slight variations as well," he said.

Size matters
Some of those variations will likely include the sizing of the boxes. TWC, it's believed, will want a smaller chassis than Comcast. CMAP calls for a maximum size of 16 rack-units (RUs). Comcast is also being more specific than TWC is when it comes to defining features like power consumption.

As for the guts, vendors are hopeful that CMAP and CESAR will be closely aligned and won't create a fragmented market for next-gen cable edge products.

Several vendors that are developing CMAP products tell Light Reading Cable that much of that work can be ported over to CESAR. "We'll have to reconcile the differences between Comcast, Time Warner and other MSOs moving forward. The heavy lifting should be the same for the two."

"It's just got a clever name to it," TWC's Pfeffer says. "We're not spec'ing out or creating new standards. These are product requirements and not definitions of new technologies."

In fact, TWC is keeping a close eye on the CMAP interface specs CableLabs is developing. As part of that work, CableLabs is looking into defining a standard XML interface for managing all sorts of access network devices. That work could conceivably encompass both CMAP and CESAR. (See CMAP Heads to CableLabs .)

"CESAR has been loose on specifying the interfaces," a vendor source says. "But they are using the right words to direct you to the CableLabs work."

CESAR timing
TWC's CESAR project is well underway, as the MSO has already cascaded its initial product requirements document to the vendors. It would then follow with a request for proposal (RFP), but the MSO isn't saying when it might put it out there.

In contrast, initial CMAP products are expected to be ready for field trials late this year and into early 2012. CMAP deployments may begin later in 2012. (See Comcast Targets First CMAP Field Trial .)

— Jeff Baumgartner, Site Editor, Light Reading Cable