Gigabit TechBlast Newsletter, January 2003 Issue

Welcome to the January 2003 edition of the Gigabit TechBlast Newsletter from DSS Networks.

   – The Gigabit Experts™

[The up-to-date resource for information on DSS Networks high-performance network solutions]

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In this months edition
  • Featured products
  • Recent Press Releases
  • Gigabit-Performance Networking Tech Tips
===== F E A T U R E D   P R O D U C T S =====

1) The new Quad-Port Gigabit Ethernet PMC Controller. Featuring 4 ports 10/100/1000, PCI-PCI Bridge, Quad-Bicolor LEDS and Fully Shielded Recessed RJ-45's all on a PMC Mezzanine Card form factor. More Info >>>

2) The new Dual-Port Gigabit Ethernet PMC Controller. Featuring 2 ports 10/100/1000, PCI-PCI Bridge, four LEDS per port and fully shielded, recessed RJ-45's all on a PMC Mezzanine card form factor. More Info >>>

===== R E C E N T   P R E S S =====


Irvine, CA - December 9, 2002 - DSS Networks announces another network first -- offering four ports of Gigabit Ethernet on a single PMC Mezzanine card - a winning new addition to their expanding family of Gigabit Ethernet products targeted for Embedded Broadband Network Applications. More Info >>>


Irvine, CA - Oct 7, 2002 -- DSS Networks achieves another network first and announces one of the fastest network benchmarks ever for running TCP/IP traffic using our Gigabit Ethernet cards at 114 megabytes per second (912 megabits/sec) of user-payload data, transferring about 3.4GB of data every 30 seconds continuously. More Info >>>

===== T E C H   T I P S =====

This month's tech-tip addresses the need to gauge the level of system performance required to run Gigabit Ethernet at "wire speed" using protocol stacks.

First we should define in our opinion just what "wire-speed" is. Gigabit Ethernet runs at 1 Gb (one gigabit) in each direction of data flow and normally operates in full-duplex mode. This equates to a total throughput of 2Gb per second or 250MB (250 megabytes) of data. The actual system level overhead is slightly less than this as there is framing overhead inserted and removed at the interface. However, you must include the total "transmit plus receive" overhead as it is the total load on the system including the PCI bus, CPU, system controller and memory that must be considered.

In addition, the load on the CPU and memory bandwidth usage will be higher as the protocol stack and socket API will cause data to be copied. So "wire-speed" is up to 250MB (2Gb) of data delivered to the application minus the Ethernet framing and protocol stack overhead or approximately 225-240MB/sec of payload data total send plus receive.

So then, just how fast of a system do I need to run Gigabit Ethernet? This is a question implementers and integrators of Gigabit Ethernet technology should ask if they want to get the best performance when using Gigabit Ethernet. While the answer depends on several system level factors, there are some basic guidelines that will help you gauge your system needs. The general rule floating around the industry is that is takes about a 2 GHZ based processor system to run Gigabit Ethernet at wire speed when using the TCP/IP protocol stack. Since Gigabit Ethernet controllers use efficient bus-master DMA, this is mainly due to the intense processing overhead of the host-based TCP/IP protocol stack in conjunction with the overhead of delivering the data to the application via the socket API interface. Based on our own internal benchmarks, the "2 GHz" rule seems to be a good one in general.

For example, our benchmarks show that we can run "wire-speed" in an end-to-end unidirectional simplex test at about 114MB (912) per second consuming only about 30 percent of a 2 GHz Xeon processor.

Other issues for consideration when using a protocol stack with Gigabit Ethernet:
  • When using TCP/IP, moderate to larger window sizes are also required to prevent "stalls" and should be 32K or larger.
  • Using UDP greatly reduces protocol stack overhead, so you should be able to get much better performance on a given system using UDP/IP rather than TCP/IP. For example, you may be able to run at wire-speed using UDP/IP using a 1 GHZ based system. UDP also eliminates the "window stall" flow control issues with TCP and allows smaller message sizes to be used. However, UDP lacks other features found in connection-oriented protocols like TCP so there may be tradeoffs to this approach.
  • Investigate other alternatives to TCP/IP such as UDP/IP, "direct IP" or other high-performance protocol implementations.
  • Our benchmarks are finding that large MTU sizes (> 1514 bytes) are generally not required as the system speed, efficient DMA and the resultant reduction of hardware interrupts lessen the need for using "jumbo frames".
Contact the DSS team via email at

Thanks for reading! We hope you found this information useful.
-- The team at DSS Networks - "The Gigabit Experts"

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DSS Networks designs and manufactures its products in Lake Forest, CA under the highest quality standards. We provide embedded solutions based on high-performance next generation broadband networking technologies including Gigabit Ethernet, 10-Gigabit Ethernet and CWDM/DWDM. DSS markets its products to OEMs, VARs and Systems Integrators.

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DSS News

At the RTECC Show in Washington DC, DSS Networks Announced a New Family of 3U Compact PCI Network Cards to Address New Market Demands.

DSS News

DSS Networks Today Announced a New Reduced Cost 12-Port PICMG 2.16 Compliant Gigabit Ethernet Backplane Switch Fabric Card Targeted at High Volume OEMS.

DSS News

DSS Networks today announced the innovative evolution of it's Model 6468 as an intelligent quad port Gigabit Ethernet server adapter with an onboard level 2 switch providing an independent bypass feature.

DSS News

DSS Networks today announced a dual port Gigabit Ethernet PMC with SC-type transceivers supporting multiple fiber transceiver wavelength options and ruggedized features for MIL-AERO.

DSS News

DSS Networks Today Announced a Next-Gen RoHS Compliant PCI-X Based Quad Port Gigabit Ethernet PMC for Telecom, Mil-Aero and Industrial Apps.

DSS News

DSS Networks Today Announced Entry into the ATCA, MicroTCA and AdvancedMC Product Market with a New Family of AdvancedMC Cards.

DSS News

DSS Networks today announced another highly differentiated extreme performance Network Product -- a new dual port Gigabit Ethernet PMC Controller with pluggable SFP transceivers supporting both fiber and copper.

DSS News

DSS Networks today announced another highly differentiated extreme performance Network Product -- a multi-port Processor PMC Gigabit Ethernet Network Processor Engine.

DSS News

DSS Networks today announced first to market extreme performance PCI-Express Switch/Interface product.

Featured DSS Networks Partners

Windriver and DSS Networks Team Up!
DSS and Wind River are teaming up together to bring you advanced embedded broadband networking solutions.

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