Standards Watch : Interoperability Between Content Delivery Networks?

The evolution of content delivery will depend on communication among key industry consortia. Just what is a content delivery network (CDN), and why is fierce activity taking place with content peering initiatives? Recently, the Content Bridge was formed by Adero, Inktomi and AOL (see "The Coming Age of Next-Gen IP Services," Billing World, November 2000), and now the Content Alliance galvanized by Cisco Systems is hoping to produce worthwhile results.

"Given the collection of independent networks that form the Internet, content peering will be essential as content delivery networks become prevalent over the Internet and in WANs," maintains Jim Melvin, director of market development in Cisco's content services business unit. Melvin spearheaded the Content Alliance initiative with Mark Day, a scientist and technical guru at Cisco. "It will happen in the same manner ISPs peer their networks today to share bandwidth and improve end-to-end performance, except with CDNs, the interest will lie in providing information between multiple content delivery networks."

The Billing Scramble

Whether multiple service providers offer free content with advertising or subscriptions to premium services, there's no question that interoperability among their CDNs will be key to their search for intelligent billing metrics that can accommodate new services. That's why a lot of "noise" is emerging from the billing world, as vendors struggle to expand their functionality in the content billing and settlement space.

"We are struggling with billing and accounting, so it is imperative that we as an industry agree on a method by which we all can communicate, whether text tool, audio or video," notes Tom Goldman, president and COO of Apogee, an active member of the newly formed Content Alliance impelled by Cisco. Goldman believes standards will roll out in three steps: automation of peering content to other networks, request routing, and accounting or billing. "Once you route user requests to your content," he says, "it will be imperative that an accounting trail be present so you know how to bill."

But before anyone can do the routing, accounting and billing, the industry will have to clearly define the value propositions and security needs for different types of content. A company in entertainment will have different needs than, say, a company dealing with ad content.

As a means to that end, the Content Alliance is working to define a specification for peering needs such as authorizing the use of content between networks, and for sharing logging or billing information for charge settlement. The technology areas on which the group will focus include content distribution and management, content routing, content edge delivery, content switching, and intelligent network services. The Content Alliance's 60-plus charter members will participate in an upcoming CDN field trial, which will enable the deployment and rollout of next-generation content networking services.

Alliance member companies include Cable & Wireless, Digital Island, Genuity, PSINet, AOL, AT&T, Digital Island, EMC, IBM, Network Appliance, Novell, Sun and the Walt Disney Internet Group.

Taking It in steps

After testing and endorsing a content peering standard, the Alliance plans to submit a draft of the standard to the Internet Engineering Task Force (IETF) in December 2000. "We don't plan on building the whole thing in one shot. We will get some published and then launch, and build on top of that," notes Melvin. At its first meeting, 83 attendees hashed out common definitions and terminology for content, which Melvin sees as a critical step to developing some structure.

"It's up to us to do the homework and deliver development work to the IETF during its December BOF [birds-of-a-feather] session," Melvin says. Cisco is hoping to parlay its efforts into an IETF Working Group on the subject of content peering. The IETF direction hasn't been strictly defined, although the Alliance expects IETF will provide AAA (accounting, authorization and authentication) support and coordination in identifying and resolving accounting issues.

Details of IETF proposals can be reviewed in several on-line drafts, including:

"CDN Peering Architectural Overview"

"Content Distribution Network Peering Scenarios"

"Accounting Models for CDN Peering"

"A Model for CDN Peering"

These and other related documents can be found at http://www.ietf.org under the section "Internet-Drafts," using its search engine and the keyword "CDN."

Clearing the Air

While there is little question that the Alliance will do the footwork, and the IETF will be the governing body in the drive toward content delivery standards, there is some confusion about how other content-related "standards" efforts from such organizations as the ASP Industry Consortium, UMTS, GBA and OBF either complement or compete with the Content Alliance.

Most notable have been IPDR efforts, which some say should complement the work of the Content Alliance. There has been some criticism that the IPDR has been very VoIP-focused, and therefore more carrier-centric than is necessary to drive next-gen CDNs. "In their charter they talk about many types of content, but when we get up to vote, because they are dominated by telco-type companies, they end up being more carrier-focused," says one IPDR member who wished to remain anonymous. Also, there have been observations from some IPDR members that things have been relatively slow-moving and low-level.

But things are changing, according to Steve Cotton, technical programs director for the IPDR and principal of Cotton Management Consulting. "It is hardly accurate to say that the IPDR organization is primarily focused on VoIP," says Cotton, pointing to the latest revision of NDM-U 2.0, which addresses e-mail, VoIP, ASP, WAP/GPRS, authentication and authorization, and wholesale use cases.

He notes that part of the problem is a misconception that the IPDR is a standards body. "The IPDR is not a standards-based body, per se, but an attempt to have standards around specific types of content, such as VoIP. We focus on reaching agreement regarding the protocol between the network/service management layer and the business/operations systems layer of the operation of IP-based service providers." As such, he says, the IPDR is not constrained to a specific service, but rather working on agreements for all services. "These services are from a consumer viewpoint, not a network element viewpoint or TCP/IP viewpoint," Cotton adds.

But extensions into the IP domain have been "tenuous at best," according to IETF chair and Cisco's (title to come) Fred Baker. "The IPDR has not seen fit to contact the IETF, and I would not describe as 'obvious' the acceptance of per-session billing as a current Internet business model," he adds. The closest Internet equivalent to a call, according to Baker, is a TCP session or corresponding UDP exchange, or a set of such exchanges between a pair of systems. These, he believes, are generally too small to really be useful. "Because CDRs are information retained about telephone calls in a usage-based billing system used by a telephone company," he says, "they are proprietary both in content and in format." Instead, the usage-based billing he sees is more along the lines of RFC 2597's measurement of committed and excess rates. "There is some degree of disconnect," says Baker.

Communication Problems

There seems to be disconnect in the communication among the organizations, as well.

"They display the classic confusion of people specialized in usage management systems-namely, equating usage with billing. There are many other applications for usage information," says Cotton, such as traffic analysis, fraud abatement, and customer service queries. "I can only note that there are significant companies spending significant resources on making sure that the IPDR organization is producing relevant results."

It seems most of the tension is brought about by lack of communication. Baker claims it is the IPDR that "has not been forthcoming with progress."

But Cotton says Apogee and Portal-dual members-bring IPDR work to the table. "There are multiple member participants who also participate at various levels in the IETF, and we rely upon them for providing liaison and validation of our work," Cotton says. Some companies that are dual members, existing both in the IPDR and the Content Alliance, believe the two organizations will complement each other. "We are active in both," he says. "It is the Cisco approach that will galvanize the IETF to work on a standard that is broader in perspective, while IPDR will focus on specific types of content."

Regardless of how it happens or who is responsible, billers' goals are to somehow have a standard analogous to that developed 80 years ago to define numbering schemes for countries and cities around the world. "The same thing needs to happen around content now," says Apogee's Goldman. "We have to agree on a method by which we all can communicate, whether text tool, audio or video. If everyone can agree on request routing, routing, distribution-we can develop a universal standard."

Whether collaborating or competing, it will be difficult for any of the aforementioned consortia to work on standards until the Supreme Court decides on royalties issues. "That is an area we are all watching closely," notes Cisco's Melvin.