networkZONE Products for the week of June 10, 2002
TranSwitch Says . . .
Super Mapper - TranSwitch's OC-48 Frame/Mapper Supports
Dynamic GigE and SAN Data Transport Services for SONET/SDH MANs
TranSwitch is pleased to introduce EtherMapTM-48, the newest member
of its EtherMap family of products for transporting Ethernet-over-SONET/SDH
(EoS). The EtherMap-48 is a unique four-channel Gigabit Ethernet mapper
with SONET/SDH framing and rich Add/Drop Multiplexer (ADM) functionality
that will enable Original Equipment Manufacturers (OEMs) and service providers
to offer new revenue generating services for existing SONET/SDH networks.
This highly integrated mapping device is targeted toward carrier access platforms with flexible Ethernet provisioning capabilities in existing metro optical networks. Carriers will now be able to satisfy growing metro data applications cost effectively while avoiding the complexity associated with legacy data transport. Additionally, carriers will be able to take advantage of extensive SONET/SDH network management and protection capabilities. The EtherMap-48 VLSI device supports mapping of multiple Gigabit or Fast Ethernet traffic and Storage Area Network (SAN) data streams into the SONET/SDH transport network at OC-48/OC-12 rates using Generic Framing Procedure (GFP) or Link Access Procedure for SDH (LAPS).
TranSwitch's EtherMap-48 blends exceptional SONET/SDH processing capabilities with optimized Ethernet payload transport to support interfaces comprised of up to four ports of Gigabit Ethernet and up to 24 ports of Fast Ethernet traffic. Mapping of block-encoded clients for SAN applications is also provided to support up to four 8B/10B encoded GigE, Fibre Channel or ESCON clients.
"The EtherMap-48's combination of EoS mapping and SONET/SDH transport will permit OEMs to more effectively satisfy emerging Gigabit WAN initiatives being launched by service providers by allowing them to build more cost-effective standards-based EoS features into their new or existing platforms. OEMs and service providers will be able to leverage the EtherMap-48's powerful features set and dramatically improve key areas of OEM platform design, namely cost, space, software integration and power," stated Robert Schwaber, TranSwitch's Product Marketing Manager for metro products.
Current implementations for combining SONET/SDH framing, Ethernet MACs, EoS mapping and path switching requires multiple discrete devices, including FPGAs and development of extensive management software in proprietary implementations. The EtherMap-48 greatly simplifies this approach by consolidating and optimizing these functions using an embedded RISC processor. The RISC-core and software suite permit outstanding data collection capabilities, thus alleviating the need for detailed device register manipulation. The EtherMap-48 incorporates additional functions for SONET/SDH framing, overhead and pointer processing and embedded RISC intelligence into a single device for EoS mapping.
EtherMap-48 also supports SAN data transport through transparent mode Generic Framing Procedure (GFP) for block-encoded client traffic in addition to the more commonly used GFP framed mode. This expands the application range for using the SONET/SDH infrastructure to transport a variety of data types.
By incorporating GigE MACs (Media Access Controllers) with flow control, the EtherMap-48 supports oversubscription of Ethernet streams. In addition, the EtherMap-48 handles traffic using either standard or virtual concatenation and can optionally function in Link Capacity Adjustment Scheme (LCAS) mode for hitless rate adaptation to dynamically alter bandwidth capacity. The device supports multiple configurations of Virtual Concatenation Groups (VCGs) to support customer requirements.
In response to network conditions such as path segment failures or periods of bursty LAN/SAN traffic, service providers can better manage and deploy customer-allocated bandwidth to achieve more efficient metro ring utilization. The EtherMap-48 allows for compensation of up to 50ms of differential delay during alignment of VCGs. To achieve this, a glueless SDRAM controller interface that requires no external timing or logic is provided for easy implementation. SONET/SDH payloads may be groomed or looped back using dual high/low order STS-1/VC-3 level cross-connects, which preserves any contiguous concatenation group and allow the path flow to be provisioned to best satisfy the application requirements.
The EtherMap-48 has been designed to work seamlessly with commercially available Ethernet and SAN switching components to enable comprehensive designs for carrier class applications. The EtherMap-48 costeffectively bridges the gap between SONET/SDH and Ethernet LANs, permitting transparent full or fractional Ethernet transport. "Service providers are delayed in the execution of native Optical Ethernet initiatives, while at the same time have chosen to continue with SONET/SDH in the short-term for stepping up their Ethernet WAN deployments. EoS technology augments the continuing notion of SONET/SDH as the primary WAN backbone layer that can generate additional immediate revenue. This is especially true for VDSL aggregation, IP DSLAM uplinks, premise Multi-Tenant Units (MTU), enhanced ADMs, terminal multiplexers and wireless backhaul electronics," concluded Mr. Schwaber.
TranSwitch will provide a complete set of support materials for the EtherMap-48,
including an easy-to-use APIbased device driver, application notes, BSDL
file, IBIS model, evaluation kit, and a comprehensive document set - all
backed by TranSwitch's world-class application engineering capabilities.
The EtherMap-48 VLSI device is implemented in 0.13 micron technology with
1.3 volt core and 2.5/3.3 volt I/O in CMOS rated for the industrial temperature
range (-40 to +85 degrees C)
analogZONE Says . . .
Sometimes, being a little conservative can pay off. Some mature companies like Agere, Agilent, and TranSwitch were a tad slow to embrace the all-IP mania of the last couple of years, and concentrated on making the most of their SONET/SDH products instead. This has paid off big time for TranSwitch, who stuck to its knitting and was one of the first companies to hop on the virtual concatenation bandwagon. While it's common wisdom now, the folks in Shelton anticipated that the incumbent carriers would be hot on this concept because it preserves the value and life of existing SONET investments. As a result, their EtherMap 3 has had strong interest from customers who are awaiting parts that will be available shortly.
Their latest product, the EtherMap-48 takes the concept of a buffered Ethernet concentrator/mapper/framer and "kicks it up" a few notches. Their new device can inhale packets from up to 24 fast Ethernet or 4 Gigabit Ethernet connections, and use virtual concatenation to feed them into a single OC-48, or four OC-12 channels. The mapper's on-chip can buffer up to 24 max-size or four "Jumbo" frames per port (most other chips use external SDRAM to do buffering.)The chip does use external SDRAM, but it's used for differential delay compensation - i.e. keeping a large number of concatenated channels aligned.
Like the EtherMap-3, it takes advantage of Ethernet's bursty nature and supports over-subscription to make the most efficient use of a SONET/SDH connection. Its built-in MAC has buffering and flow-control to match and rate-adapt uneven flows to the steady TDM streams. The buffers use programmable thresholds or "watermarks" to help manage network latency issues. About the only limitation to its Ethernet capabilities is that it is a full-duplex-only device, and does not support the backpressure mechanism used in half-duplex systems.
Since flexibility is a hallmark of TranSwitch products, it's no surprise that you can also mix-and-match nearly any combination of Fast, and Gigabit Ethernet streams that fall within its capacity limits. And, of course, it supports both GFP protocol, well as the Asian LAPS (GFP equivalent) mapping standard. You also can handle the recently-approved LCAS protocol that adjusts source and sink node link capacity on the fly.
In addition to its GFP/LAPS-compliant framer, the EtherMap-48 has a pair of on-chip cross-connects. The first one is used to re-direct traffic at STS-1 granularity while maintaining all concatenations. The streams are then passed to a TU-3 pointer-tracker that breaks the flows down into VC-3s, and a second cross-connect that switches the VC-3 streams. This allows for very flexible cross-connect, network diagnostic loop-backs, and protection switching.
If you're running in the quad OC-12 mode, the chip can mix-and-match framing protocols with one port running GFP while the other runs transparent mode. For those of you who need it the EtherMap-48 also runs linear-mode GFP which stat-muxes all four Gig Ethernet ports into a single pipe.
But the chip's versatility does not stop here It also supports SAN traffic running on either FibreChannel by connecting its four- 8B/10B SERDES interfaces to the appropriate PHYs and using GFP's transparent mode that simply encodes and decodes (plus rate adaptation) the stream without regard to format. You can also talk ESCON via its parallel interface.
And if that's not enough, it has an embedded Tensillica RISC core with driver software to handle overhead processing, plus configuration and stats collection. In contrast, their EtherMap-3 had similar software, but it ran on the host processor.
This chip should be a natural for use in any equipment that bridges a SONET/SDH infrastructure and an IP edge network. My only concern is the exceptionally long lead-time that TranSwitch is giving us for this part. While I understand that it is anxious to keep up with the flurry of Ethernet-capable OC-48 framers recently making the scene, it's out of character for the usually conservative company to pre-announce a part 6-8 months ahead.
Given their past performance, I'm pretty confident
that TranSwitch will deliver the goods, and that it will be worth the wait
for those designers whose designs won't be shipping until early next year
anyway. The device is scheduled for customer trials in Q1'03 and will be
priced at $550 each for quantities of 1-k units.
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