GFP optimizes storage over SONET

Companies are increasingly focused on developing disaster-recovery and business-continuity plans to minimize the effect of large-scale service disruptions. And some sectors such as healthcare and financial services must meet regulatory requirements pertaining to data security and availability. To meet the need for rapid recovery and restoration, organizations are looking to extend the reach of their storage-area networks.

Generic Framing Procedure (GFP) is an encapsulation method that is helping answer the call for SAN extension by letting Fibre Channel SAN traffic be carried directly onto the SONET network in an efficient and cost-effective manner. This technology provides a standards-based way to carry Fibre Channel and Fibre Connection (FICON) storage traffic seamlessly over SONET circuits without any changes to the SONET infrastructure.

SONET is the underlying transport protocol that carries all enterprise voice, video, data and storage traffic across metropolitan-area networks and WANs. SONET is particularly well-suited to carry enterprise mission-critical storage traffic because it is connection-oriented, and latency is deterministic and consistent. It is also secure and resilient, possessing both in-band and out-of-band management and sub-50-millisec failover.

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Companies are increasingly focused on developing disaster-recovery and business-continuity plans to minimize the effect of large-scale service disruptions. And some sectors such as healthcare and financial services must meet regulatory requirements pertaining to data security and availability. To meet the need for rapid recovery and restoration, organizations are looking to extend the reach of their storage-area networks.

Generic Framing Procedure (GFP) is an encapsulation method that is helping answer the call for SAN extension by letting Fibre Channel SAN traffic be carried directly onto the SONET network in an efficient and cost-effective manner. This technology provides a standards-based way to carry Fibre Channel and Fibre Connection (FICON) storage traffic seamlessly over SONET circuits without any changes to the SONET infrastructure.

SONET is the underlying transport protocol that carries all enterprise voice, video, data and storage traffic across metropolitan-area networks and WANs. SONET is particularly well-suited to carry enterprise mission-critical storage traffic because it is connection-oriented, and latency is deterministic and consistent. It is also secure and resilient, possessing both in-band and out-of-band management and sub-50-millisec failover.

Previously, corporations had to convert storage traffic to intermediary protocols such as ATM, frame relay or IP to access the SONET network. This added more overhead and security, resiliency, latency and performance problems.

GFP can be deployed as an interface on an optical switch and lets companies more efficiently utilize their SONET circuits. They can use GFP at the edge of leased SONET circuits (such as OC-3, OC-12, OC-48) and then can allocate portions of that circuit using virtual concatenation (VCAT) for storage, voice, data, video and the like. VCAT is a transport technology defined by the ITU-T (G.707/G.783) to extend the utility of the SONET transport layer by letting bandwidth be allocated in multiples of 50M bit/sec Synchronous Transport Signal increments using only the bandwidth an application requires.

The cost-effectiveness of GFP is greatly improved with VCAT. Companies benefit because they can send data at the optimal bandwidth, and service providers benefit because they can maximize the efficiency of their overall network.

Corporations also do not necessarily need private SONET rings to benefit from GFP. If they do have private SONET rings (that is, they have fully dedicated OC-192 SONET bandwidth vs. part of the SONET bandwidth) they also can use GFP to get better utilization and efficiency of their SONET infrastructure.

The emergence of GFP enables a very efficient mapping of storage protocols directly onto the widely available SONET infrastructure. This process is facilitated with a SONET add/drop multiplexer, which transforms Fibre Channel and FICON traffic directly into SONET payloads, which can then be transported over a SONET WAN.

For example, connecting two SANs with 200M bit/sec of Fibre Channel traffic previously would have required a dedicated OC-12 of bandwidth, effectively utilizing only 35% of the bandwidth. With storage over SONET using GFP with VCAT, companies utilize and pay for only 200M bit/sec of bandwidth. The net result is 65% lower bandwidth and lower cost by implementing storage over SONET.