All-optical Raman amplification supports network-architecture strategies that meet these enterprise requirements while providing opportunities for lowering network capital and operations expenses. It’s a new role for the technology. Distinguished from Erbium-based amplification in that it does not require doping of optical fiber, Raman amplification is compatible with the enterprise’s or managed service provider’s already installed base of single-mode fiber and supports superior transmission characteristics and longer span lengths. Once primarily utilized in addressing cost issues in service provider long-haul networks and submarine systems, Raman amplification today can be cost-effectively deployed to support single-span transmission at 10Gbit/s over distances of 200 km in enterprise networks. Depending on the length of a given fiber span, this eliminates or reduces the necessity of huts needed to house in-line amplifiers, as well as the maintenance burden and security concerns that are associated with such facilities.
Raman amplification offers network owners – enterprises as well as service providers – significant savings across capital expenditures (CAPEX); engineering, furnishing, testing and installation (EFI&T); and operations, administration and maintenance (OAM). Most importantly in regard to storage area network (SAN) services, reducing the number of amplifiers heightens network availability and lessens an enterprise’s exposure to disasters and other events that threaten network survivability.
New Demands in Enterprise Networking
A greater awareness of the cost of network downtime and a need for more flexible operational models have driven a wider array of enterprises than ever to implement sophisticated storage services. But perhaps the biggest driver of all behind the trend is regulatory pressure. Government regulations such as the Health Insurance Portability and Accountability Act of 1996 (HIPAA) and the U.S. Security and Exchange Commission’s rule on Retention of Records Relevant to Audits and Reviews are stipulating precisely how enterprises in more and more industries archive and safeguard data.
In the most demanding scenarios, enterprises require synchronous applications such as Continuous Data Protection (CDP). In this emerging application, disk technologies steadily record data updates in real time. Data is simultaneously written to disk at primary and secondary data centers – and time-stamped. In this way, CDP delivers the unprecedented capability for an enterprise to revert to data at any point in time, instead of a snapshot of data recorded on a preset interval (every four hours, for example).
WDM-enhanced fiber-optic networks – delivering protocol-agnostic, robust connectivity and reliable service – have emerged as the standard medium for CDP and other types of synchronous, business-continuity and disaster-recovery services. The rollout of Dense WDM (DWDM), Coarse WDM (CWDM) and hybrid CWDM/DWDM platforms has made it cost-effective for more enterprises to implement sophisticated storage capabilities. These innovations allow the enterprise to deploy only the precise amount of capabilities they require for their Recovery Time and Recovery Point Objectives (RTOs and RPOs) of the given moment – and affordably add traffic channels and bandwidth as new needs arise.