Architecting Collaborative Applications (Part II of II)

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To read Part I of this article, click here.

Planning a collaborative architecture

The figure below illustrates the business process and the ways that collaboration technology can accelerate it. The top layer depicts the business architecture, which connects people who access, use and transform information in accordance with a process that is aimed at achieving a business result. Collaboration is of paramount importance when it comes to optimizing the business process.

Figure 3: Collaborative Architecture (click here to enlarge image)

The three lower layers represent the technology architecture. This is where EAs model the business process and break it down into self-contained steps that ideally map to modular, reusable services. Within the enterprise applications layer, the composite applications illustrated here draw services from traditional applications, as well as using communications and collaboration services and network-based services to present the optimal tool to users.

Network-based services are vitally important when enabling a collaboration architecture that can mash up enterprise applications and collaborative elements with business-critical determinism. Resource allocation and policy are vital to support emerging collaboration models.

It is important to understand that while reusable network services can greatly enrich composite applications, they cannot compromise network availability or manageability. Rather, they can and should result in an overall network infrastructure that is easier to manage and able to fix itself whenever possible. Many of these services are easier to scale, manage and reuse when they reside in the network. All of these functions merge into a homogenous intelligent network cloud that ensures functionality transparently end to end.

Not only are these composite applications helping to bring down the walls between collaboration, application and data silos, but they also are beginning to blur the boundaries between the traditional organizational silos in IT. EAs, application developers and networking professionals must work together to best support the business process and innovate with collaboration.

The network as a platform for composite applications

Integrated network services accelerate and secure the composite application infrastructure, providing vital performance and security enhancements and overcoming concerns in those areas. In addition, the network helps enable communication and collaboration services that greatly enrich the emerging composite application world. By enriching these applications with powerful network services that support more effective collaboration, enterprises can realize significant and measurable productivity gains.

Because of the nature of composite applications, there is a 100 percent correlation between network availability and application availability. The different Web service components communicate with each other across the network, and any break in communication means that the orchestrated application cannot run. In addition, depending on the design of the composite application, there can be varying degrees of correlation between network latency and overall application performance. Network latency adds to the "time-to-complete" of each component and can decisively contribute to the time-to-complete of the entire composite application.

XML is emerging as the lingua franca for composite applications. Thus, network-based XML-aware acceleration, virtualization and security services ensure that any application gets the type of QoS and security that benefit it.

Because XML messages are encoded in human language, they are long and verbose, making them a prime candidate for compression. Compression reduces latency, especially over wide-area links, and greatly enhances application performance for remote users or branches.

Increased strain on processing resources is another concern. Some experts have opined that SOA places too much strain on the existing IT infrastructure. Arguably, protocol overhead like repetitive parsing, validation and transformation functions consume CPU horsepower that ideally should be dedicated to running the business application itself. As the Web services infrastructure grows, so too does the CPU penalty and the impact on application performance. Offloading these overhead functions to the network greatly helps application performance.

Finally, by definition, composite applications are open and distributed. This openness allows for unprecedented flexibility, but such a distributed application infrastructure also provides new vulnerabilities and more points of attack. Surrounding the monolithic enterprise application block with security walls will simply no longer work in an environment that, by definition, thrives on openness. Web services are under increasing scrutiny from a security standpoint, and this remains an area of great concern to EAs and CIOs as they set out to implement SOA. Network-based security services provide relief.


Collaboration is a powerful tool as businesses examine ways they can thrive in uncertain times, allowing employees to become more productive as they embrace new ways of working and leverage real-time access to information. An effective collaboration strategy is a requirement as the boundaries of the enterprise grow porous and encompass remote workers, partners and customers.

Enterprise architects are challenged to improve business processes and increasingly look to SOA and Web 2.0 mashups to help achieve this goal. Network-based services play a key role in accomplishing the overarching objective of aligning business and technology architectures and helping deliver new application models. In particular, SOA and mashups can create this new generation of end-to-end collaborative applications with rich user-interaction experiences, robust performance and high security.

About the Author

Paul Liesenberg is an Enterprise Architecture and Technology Manager for Cisco where he develops methodologies that optimally align next-generation infrastructures and overarching business processes. Prior to Cisco, Liesenberg was VP of Strategic Marketing for ZettaCom and Bivio Networks, orchestrating product and partnership strategies. Earlier, he was with Cisco through the acquisition of StrataCom, and was previously with Nortel's Data Networks Division and Siemens' Public Networks' R&D division. Liesenberg holds two patents in the area of VoIP, and an M.Sc. from TUM (Technische Universitaet Muenchen).

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