Electronic Design

Access Processor Aggregates Multiple Protocol Traffic For Carrier Ethernet Transmission

An excess of acronyms represents the protocols used in carrying various types of data traffic. Nowhere is this more profound than in cellular communications, where basestations must maintain the older legacy protocols as well as implement all the new ones. The challenge in making equipment that can handle this job lies in pulling all those different protocols together and transmitting them over a lower-cost medium.

That lower-cost medium is gradually emerging as carrier Ethernet that can replace older T1-E1/ATM/Sonet systems, which work well but are very expensive. Wintegra, a provider of packet processors and software for wireless and wireline infrastructure equipment, now has a way to aggregate all that data into a manageable format. Its WinIP family of IP-only silicon and software provides the intelligence and upgradeablility for infrastructure equipment to support the emerging networks based on the convergence of voice, video, data, and wireless services.

The WinIP solution combines a network processor optimized for access and aggregation and the related software. It suits emerging carrier Ethernet applications such as wireless backhaul connectivity between wireless basestations, wireless Long-Term Evolution (LTE) transport, and Metro Ethernet access.

However, the migration to an all-IP network doesn’t simplify the protocol processing requirements in new equipment. Simple switches aren’t sufficient to provide advanced encapsulation such as MPLS, L2TP, GRE, and Ethernet pseudo-wire. Additionally, they aren’t sufficient to handle quality-of-service (QoS) features such as shaping, policing, and remarking IP packets needed by carriers to offer service-level agreements (SLAs) to their customers.

With a WinIP processor and Wintegra’s array of free protocol processing software, though, vendors can build a cell-site aggregator that packages all the T1/E1, ATM, OC3, AAL2/5, PPPmux, ML-PPP, and other protocols into carrier Ethernet for cost-efficient transmission to the central office. These multicore processors contain both data-path and control-path processing (see the figure).

The control path uses a 24k MIPS core running at up to 600 MHz, while the data path uses up to six 350-MHz Wintegra proprietary data engines optimized for data handling. The initial devices support up to four 1-Gbit Ethernet (GbE) ports or 24 Fast Ethernet ports. The memory is external so its size can be optimized to the application.

The processors can use DDR-I or DDR-II SDRAM or SRAM with error correction coding (ECC) support. The WinIP devices have on-board hardware accelerators for shaping, integrated encryption support, and testdata- in (TDI) clock generation circuitry. Other interfaces include PCI 2.2, POS2, or SPI.3 and up to four serial TDI ports.

The free software that’s included saves a massive amount of time and cost in new product development. Support includes PPPoA/PPPoE, bridging/routing/switching, GRE/GTP, L2TP, and synchronous Ethernet. QoS support includes Ethernet OAM, BFD/ VCCV, packet classification, hierarchical shaping, WRED, statistics/ billing, and 2 Rate 3-Color marking.

Advanced L2 protocols are all available. Wintegra’s supplied Carrier Grade-Wintegra Device Driver Interface facilitates interfacing with your own software. Two of the planned chips and all of the software are available now.

WINTEGRA www.wintegra.com

See associated figure

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