*****OT**********
Or, sort of off topic.
I don't understand what Cerent has that's worth several billion to Cisco --- or anyone else.
As background, I went to NN's website to see what they did with SONET/SDH.
newbridge.com
Then I went to Cerent's website and found an article published in Telecommunications Magazine:
SONET: Still an Absolute Necessity
Optical Networking
Evolutionary optical platforms that protect existing infrastructure could be the key to solving the transport bottleneck.
Terry Brown
With a deployment rate of $8 billion per year in North America, SONET is still alive, well and growing. It?s the de facto standard in the transport space due to its innate survivability, reliability, interoperability and manageability. But the limitations of traditional SONET transport systems are becoming evident. They were designed to transmit fairly predictable levels of voice traffic using time division multiplexing (TDM) and they have done their job well, but the world is changing. There is a steady shift toward transport of high-volume and increasingly dense data traffic over the Internet and virtual private networks (VPNs). To accommodate subscriber requirements, service providers must implement systems offering more bandwidth along with cell- and packet-based technologies. Yet there are numerous complexities associated with expanding network capacity and integrating cell and packet technology into the existing network infrastructure. The most significant issue is that traditional SONET transport systems cannot scale quickly to accommodate the massive bandwidth demands and increasingly rich data traffic that is bursty by nature.
The Building Block Dilemma
The dilemma with traditional SONET transport systems is twofold. The first problem lies in the equipment?s partitioning of line rates; the second involves how nonoptical DS-3 and DS-1 signals are groomed and managed. The current SONET optical transport infrastructure utilizes bit-rate-specific TDM to generate required OC-n line rates from OC-192 (10 Gbps) down to OC-3 (155 Mbps). In other words, specific network elements supporting each OC-n line rate must be deployed along the entire network transmission path in order to deliver SONET synchronous transport signal (STS) payloads at the desired bandwidth (see Figure 1).
Dropping out lower line rates requires cascading network elements. For example, an OC-192 platform may only have the ability to drop out an OC-48 optical signal. As a result, to achieve a nonoptical DS-3 (45 Mbps) or DS-1 line rate (1.55 Mbps), which service providers use for a majority of their subscriber services, OC-48 network elements may have to be added to drop out an OC-3 service level. This, in turn, will deliver the DS-1 signal on its virtual tributary. The opposite problem holds true when providers seek to add bandwidth as network traffic demands grow. If a carrier is using OC-3 equipment and needs to deliver OC-48 line rates, another equipment bay must be added at each point along the network transmission path where OC-48 service is to be offered.
When provisioning DS-1 and DS-3 services, the problem occurs again. These services must be derived from SONET using digital cross-connect subsystems (DCS). As a result, yet another TDM circuit variant--one relying on multiple elements designed for the specific line rate--must be used. Now take the concept one step further. If data services based on cells (such as ATM) or packets (such as IP) need to be provisioned over SONET, different fiber must be used for the physical transmission path and totally different network elements must again be implemented. In all the scenarios described above, a service provider?s pain becomes evident. Its symptoms come in the form of spiraling equipment and fiber costs and added management overhead. There?s also a high probability that some equipment cannot be reconfigured to deliver scaled up bandwidth and services.
Taking Evolutionary Steps
Solving this transport bottleneck created by the explosion of data and video services requires making TDM-based SONET transport scalable and multifunctional. The solutions lie in evolutionary optical transport platforms that can be used within the existing network infrastructure.
From a network planning and design perspective, simplicity, flexibility and cost are crucial to success. What technologies are available that will increase the network?s capabilities and value while still offering interoperability with the embedded infrastructure of SONET network elements and operations, administration, management and provisioning (OAM&P) systems? What technologies can be deployed today without incurring a massive network overhaul? What technologies are field proven?
Answers are found in three dimensions of evolutionary optical transport platforms: simplicity, efficiency and value. First, the complexity of SONET transport solutions must be reduced. Integrating the capabilities of multiple network elements into one platform will simplify and supercharge the SONET transport network simultaneously. Second, the efficiency and functionality of SONET transport must be dramatically increased to support not only traditional voice applications, but data and video as well. Finally, new systems must offer tremendous value in the form of low first cost, ease of engineering and installation, and provisioning. These are essential operational facets for competitive carriers who must deliver various levels of service on demand. Delivering on the simplicity, service flexibility and value proposition requires taking an evolutionary approach to network configuration. It?s an approach that impacts the physical plant and equipment, how fiber is utilized and how operational support is provided.
An evolutionary optical transport platform integrates the functions of multiple SONET network elements into one. This helps carriers and service providers leverage their embedded optical transport network investment, and it effectively supercharges their SONET infrastructure. These systems are designed to collapse the functions of multiple line rate SONET network elements--from OC-3 up to OC-192--into one platform. This alleviates the need to deploy a cascading collection of different bit rate-specific devices for varying levels of transport services. To support nonoptical DS-3 and DS-1 line rates, these next-generation platforms also incorporate 3x3 and 3x1 DCS in the same chassis.
Evolutionary optical platforms also offer unprecedented multiservice network capabilities in the same box. This maximizes the use of existing fiber, rack space and power. In addition to being able to configure DS-1 and DS-3 line rates on the fly, cell- and packet-based services such as ATM and IP, plus additional services such as video, can be added by simply plugging cards into the chassis. This supports rich data traffic such as transparent LAN services, cable modems, and streaming audio and video.
Combining the functions of a SONET multiplexer, a digital cross-connect switch and an ATM/IP data switch into one network element is the best new optical transport solution. Besides the obvious transport benefits, these systems draw less power, have a smaller footprint than traditional network elements, and are built to scale as bandwidth requirements grow. As a result, the transport network becomes simplified. Economically, these capabilities set a dramatically different value point. There is a significantly lower first cost when using evolutionary optical transport systems: Their cost is approximately one-half that of traditional SONET network elements. Furthermore, system costs over time are lower due to ease of engineering, installation and use. Best of all, these cost benefits can be extrapolated across the board to any service provider market segment, including ILECs, CLECs, cable TV providers, utilities, IXCs and ISPs.
Inside Evolutionary Optical Transport Systems
When compared to the rigid, bit rate-specific systems currently available, evolutionary optical transport systems by definition are able to support today?s requirements. They also have a built-in ability to allow migration to additional services and capacity expansions as needed in the transport network. New optical systems are founded on several key attributes. These include integration of sophisticated ASIC technology, form-factor design improvements and the proliferation of highly robust and reliable optical components.
By design, these systems are bit rate agnostic and are able to accommodate multiple services and SONET bit rates in the same platform on either end of the network. They are able to aggregate any service type including TDM, ATM, IP, video and frame relay onto SONET backbones at any bit rate. Thanks to multidimensional flexibility, these evolutionary optical transport systems can interoperate with traditional SONET products and with data and video networking equipment. They also work with existing operations support systems (OSS). Integrated bandwidth management functions support cross-connect capabilities, data switching and over-subscription features to ensure that SONET bandwidth is used efficiently and is well-packed.
While demand for network access skyrockets and core networks rapidly expand, traditional SONET equipment designed for voice networks will crack under the load of surging data traffic unleashed by the Internet and broadband VPNs. A new generation of optical transport is required to break free of this dilemma. These products must be able to work in existing SONET networks in order to be cost-effective today, and they must also be able to evolve to support wavelength division multiplexing (WDM) and other optical transport options as they become economically viable. The evolutionary systems available now can support any network traffic type over any optical bit rate at a 50-percent lower cost than traditional SONET solutions. Service providers that demand simple, scalable and efficient transport systems can capitalize on the incredible benefits these new optical transport systems provide.
Terry Brown is vice president of field operations for Cerent Corp., focusing on marketing and sales. Before joining Cerent, Brown led the sales and marketing efforts at Advanced Fibre Communications and Teradyne. Brown holds a B.S.E.E. degree from the University of Notre Dame and a master?s degree in marketing and economics from Northwestern University?s Kellogg School of Management. Contact him at terry.brown@cerent.com.
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And, finally, I found stats on the Cerent 454, itself:
cerent.com
Who is most impacted by Cerent's products? Does it compete with anything NN has, or would Tellabs or DSC(ALA) be more threatened?
I need help. . .
Pat |
