Changing role of software
Service provisioning, made possible by the latest generations of software, is bringing the benefits of fiber to light.
BY PANKAJ SHAH, PATRICIA CHRYSTYCZ, Gambit Communications Inc., and MATT HOFFMAN, Appian Communications Inc.
Speed is the name of the game in transmitting voice and data. Speed's the reason for upgrading line service-even making the jump to fiber. But with carrier services, the speed of implementation always was the antithesis of the promised line speed-time-consuming provisioning, delays in availability of services, and mind-numbing planning exercises took the sheen off the gift of the promised data or voice speed and bandwidth improvements. In the optical arena, with its promise of even more speed, how can service providers deliver that speed to their customers...well, speedily?
One fast path to improved customer satisfaction for service providers is a new breed of solutions focused on dynamic delivery of optical services. As a service provider, imagine being able to do all the previously mind-numbing work with sophisticated software and a click of the mouse. This new breed of solution eliminates multiple truck rolls and equipment upgrades, saving service providers the substantial costs of deploying personnel and significantly reducing the time it takes to generate new revenue.
But behind the scenes, how do these new optical access solution providers assure that their powerful software is ready for market at the same time as their hardware? The solution is sophisticated simulation tools that shorten time-to-market while assuring functionality.
In the software-development environment, there is a constant struggle over the availability of networking devices-a struggle that's time consuming and unnecessary. Vendors never seem able to meet their software developers' needs for devices. It seems there is an unquenchable thirst for devices from the developers that design and program the device-management applications to the quality-assurance personnel in acceptance labs (see Figure 1).
This situation in the optical-software-development environment is especially bleak-every piece of interoperable third-party equipment must be purchased with hard-won capital budget money. Additionally, the time to research, purchase, install, inventory, and depreciate consumes human resources-resources that could be spent developing software.
Today's optical-service access solutions allow carriers to deliver high-speed business services more rapidly and with greater service flexibility. Optical hardware and provisioning software, along with element management, are deployed at the edge of service-provider networks, eliminating the bandwidth bottlenecks, service delays, and high costs that plague current first-mile infrastructures. Such solutions speed service deployment via soft-tunable, bandwidth-guaranteed Ethernet services interfaces that deliver multiservice access over the SONET/ DWDM optical core.
Optical-solution vendors can dramatically shorten the development cycle of their provisioning software and element managers by using simulators to virtually reproduce the devices-even before prototypes of the hardware are available in the labs. This allows optical-solution providers to deliver both the hardware and a full-featured, robust software suite to their first beta customers.
Simulators allow developers to set up virtual labs (see Figure 2) that are more extensive than could be available physically-labs that would be well out of their reach financially. With simulators, the developers can truly validate the scalability of software applications and test those designs against the simulator's virtual devices. Because simulators were developed to extend the lab environment inexpensively to meet these needs, one workstation can often simulate thousands of devices.
Today, optical-solution vendors are using such tools to simulate large networks of optical hardware to validate scalability and availability. These vendors anticipate optical access networks to grow to hundreds or even thousands of nodes. Simulators allow them to test networks of this size without dedicating large amounts of hardware or personnel resources.
To duplicate any existing lab, simulators can record the network and use that recording as input to a simulation of the network. Management applications can then be run against "virtual labs"-simulated networks that provide testing needs during development. Developers are then free to test their applications. They can run tests using the simulated network, such as disabling virtual devices, port, or interfaces to see how the management application reacts. They are also free to experiment with changes in the network to test features like real-time service activation and modification. Network faults can also be introduced without worrying about the impact to other developers.
Actually using the applications in simulated network environments can give developers an accurate appraisal of the software-and an assurance that the software will perform to specifications in the sales brochure. Also, there are no more assumptions on the developer's part about whether an application will scale as specified. Simulators allow them to play "what if" games with their configuration to make sure the application can hold up firm against all positive and negative conditions.
Simulators reduce the initial capital costs of the lab by factors of between 10 to 1,000, since there is no need to buy the variety and quantity of hardware from different vendors. Less equipment also means less real estate, infrastructure, and support staff. The type of hardware deployed in carrier networks is virtually unlimited, because simulators allow developers to design and test against virtual hardware-a huge savings in capital equipment. The software vendor is also assured that management applications perform properly when these devices are encountered in customers' networks.
Generally, multiple people with different needs share the same lab, complicating the difficulty of maintaining the lab infrastructure. Testers may require a sizeable network, for example, to test the scalability of the application. A developer implementing policy scripts may need to reproduce fault conditions to ensure proper operation. The lab time-sharing method affects development schedules. With simulations, individual developers can have their own networks on their own machines all the time. This results in significantly faster production schedules.
Negative conditions happen very infrequently and are hard to recreate. With simulations, even pathological conditions are easily reproduced, since control is provided for every single management-information-base (MIB) object instance at any time. Instead of using traffic generators, call generators, or any other physical device, simulators supply a batch-processing environment that can run unattended.
Simulators generally have different tools, such as a graphical user interface (see Figure 4), agent simulator, recorder, a compiler and a shell command-line interface. Some simulators also come with easy-to-use wizards that provide a user-friendly way to compile, record, and simulate huge networks.
Such simulators often ship with a large library of simulated devices, networks, and pre-compiled MIBs from the leading networking companies. These libraries should be updated frequently by the simulator vendor.
In the fast-paced world of optical networking, new devices and new services are constantly added. Whenever a new hardware device is introduced, it can be added to the simulator's device library and included in testing or training within days of being released by the manufacturer.
Using simulation capabilities, developers can create new designs and test them for operational control even before the hardware becomes available. This capability allows optical-solution vendors to develop and validate software features and functionality before hardware is available in the development labs, significantly reducing the time to market.
Simulator screens (see Figure 5) provide a user interface for dynamic modification and activation of services, real-time performance monitoring statistics, and trap viewing.
The use of simulators extends beyond development testing for optical-management vendors. For instance, the marketing department can use simulators for trade shows and customer demonstrations. During trade shows, the simulated optical network contains multiple network elements with a real mix of devices and connections. This facilitates customized demonstrations targeted at a particular audience-without the trouble of setting up a real network. A virtual demonstration lab enables the optical company to carry the network in a laptop, a big improvement for sales presentations.
In addition, optical companies can use simulators in their support environments. Support personnel can capture actual customer network scenarios and play them back to aid in troubleshooting, significantly shortening the problem recreation support step. Finally, simulators are designed to overcome many limitations in management software-application development and testing.
Pankaj Shah is CEO and co-founder and Patricia Chrystycz is marketing consultant of Gambit Communications Inc. (Nashua, NH), and Matt Hoffman is senior product manager for Appian Communications Inc. (Boxborough, MA). They can be reached via their company's respective Websites, www.gambitcomm.com and www.appiancom.com.