Flexible framer juggles with datarates

Cypress Semiconductor is sampling a device it dubs the industry's most advanced Sonet/SDH framer.

Cypress Semiconductor is sampling a device it dubs the industry's most advanced Sonet/SDH framer.

Operating at OC-48/STM-16 (2.5Gbit/s) speeds, POSIC2GVC uses virtual concatenation to dynamically allocate up to 16 channels of voice and data, providing right-sized, secure and dedicated bandwidth for high-speed data networks.

POSIC2GVC supports generic framing procedure (GFP), which makes it possible to transport any protocol over Sonet/SDH, including Gigabit Ethernet, Fibre Channel, enterprise system connection (ESCON) and digital video broadcast (DVB).

POSIC2GVC features packet preclassification, offloading work from the network processor, thereby enabling higher performance.

POSIC2GVC is ideal for metropolitan area network and wide area network carrier-class routers, switches, add/drop multiplexers and dense wave-division multiplexing communication systems.

"At the metro level, there is tremendous pressure for expanded capacity to support broadband local access and high-speed WAN", said Christopher Norris, vice president of Cypress's data communications division.

"Although having wider pipes is imperative, dynamic service provisioning-being able to instantly allocate bandwidth to guarantee quality of service-is critical.

POSIC2GVC can dynamically allocate bandwidth in milliseconds versus days, which is typically what carriers and service providers need in order to provision a high-speed line.

Service providers can easily upgrade their networks to efficiently transport multiprotocol and multirate data simply by adding POSIC2GVC to the end nodes only".

"Dynamic bandwidth allocation will have a major impact on both users and service providers, and this is the functionality added with the new Cypress chip", said Allan Armstrong, Director of Optical Transport Semiconductors at RHK, a leading telecommunications industry analyst firm.

"This kind of framer IC lets carriers group any number of STS-1 channels for transporting data, regardless of the source or type of data packet.

This is important because it lets service providers supply bandwidth on demand to meet changing QoS requirements without having to charge for dedicated bandwidth".

"POSIC2GVC has already received tremendous response from our customers", said Ralph Schmitt, Cypress's vice president of sales and marketing.

"We have engaged in key platform designs with multiple corporate accounts and have shipped samples for prototype builds.

Using POSIC2GVC our customers are able to quickly upgrade their equipment to offer highly configurable and optimised services and in turn enable their customers-the carriers/service providers-to increase efficiency while keeping costs down".

POSIC2GVC is a pioneer in supporting generic framing procedure (GFP) at OC-48/STM-16 rates, supporting both framed GFP (GFP-F) and transparent GFP (GFP-X).

GFP is a way to encapsulate any protocol for transport over a Sonet/SDH network.

Using POSIC in GFP mode, a carrier can efficiently transport any data over standard Sonet/SDH networks with no degradation of service and no waste of bandwidth.

POSIC2GVC enables service providers to oversubscribe data channels.

For example, a line card can have four Gigabit Ethernet ports.

POSIC2GVC would create four virtual channels of equal bandwidth - namely 622Mbit/s.

When a customer requires the full use of a dedicated channel (1Gbit/s datarate), the service provider can change one of the virtual channels to be 1Gbit/s while reducing the other three channels appropriately.

This flexibility helps insure high levels of service and efficient use of the network.

In addition, POSIC2GVC offers packet pre-classification, which provides a "bandwidth boost" to the network processor/link layer device on the line card.

Packet pre-classification allows separation of the control and data packets.

It enables on-chip parsing and label lookups for multi-protocol level switching (MPLS) packets, freeing the network processor from having to analyse every packet.

The POSIC2GVC is also a pioneer in supporting virtual concatenation, a new IEEE standard.

Within Sonet's synchronous transport signal-n (STS-n) structure, a special "c" class, (STS-n "c") defines concatenated synchronous payload envelope (SPE) structures for ATM signals.

Normally Sonet equipment may not disassemble STS-nc SPEs into lower-rate Sonet signals but must transport entire SPEs unchanged.

Each user grabs a fixed amount of bandwidth in the fixed OC48 frame.

This inflexibility results in partial packets being passed along in OC-48 frames, with a great deal of waste and resulting lack of bandwidth.

Current OC-48 framers typically waste half of each frame when processing Gigabit Ethernet packets.

Current ASIC approaches to solving the problem are only partially successful.

POSIC handles this problem by dynamically allocating all bandwidth between users, depending on the type of data involved.

Virtual concatenation with up to 16 channels provides POSIC with the capability of providing secure, dedicated and right-sized bandwidth for LAN and ATM transports.

It also enables transport of packets larger than standard SPE size transparently through the network.

Virtual concatenation can be done with STS-1 or STS-3c granularity.

Clear channel mode enables transport of TDM traffic on selected virtual channels, while all other virtual channels will transport a selected data type (e.g ATM, POS etc).

Production samples of CY7C9536-BLC (POSIC2GVC) are available in a 504-pin BGA.

Pricing starts at $400 in quantities of 1000.

An evaluation board and device driver API are also available.

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