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Ethernet Extenders - A Fiber Alternative Made Easy


Extending a point-to-point transmission beyond the 100-meter Ethernet limitation typically involves using fiber cables. However, deploying a new fiber infrastructure can be difficult to justify in a cost-benefit analysis, and far more time-consuming than leveraging existing copper wiring resources. According to a 2009 entry of the U.S. Department of Transportation, installation for one mile (1.6 km) of single mode fiber optic cable (96 fibers) can cost as much as USD 11,880.

Moxa now offers a cost-effective alternative to this dilemma, the DSL Ethernet extender, to drive long-range and high-speed data communication over existing voice-grade copper wires between geographically separated LANs, or LAN devices, for a very cost effective bridged-Ethernet connection.

Typical entry-level DSL Ethernet extenders promise a "plug-and-play" installation. However, engineers/integrators can still encounter device limitations during deployment, management, and maintenance. Moxa's managed DSL Ethernet extenders offer industry-leading features to effectively reduce deployment time, simplify maintenance, and enhance manageability.

Zero configuration for easy installation

Working in pairs, traditional Ethernet extenders must have one designated as the CO (Central Office) device, and the other as the CPE (Customer Premise Equipment) device (see Figure 1). Having similar device types at both ends (CO to CO or CPE to CPE) will disallow the extenders to communicate. Many entry-level industrial DSL Ethernet extenders promise "plug-and-play" installation but still require manual configuration through the web browser or device DIP switch settings to designate one device as the CO and the other device as the CPE.

Moxa's managed DSL Ethernet extenders can provide auto CO/CPE negotiation (see Figure 2), which requires zero configuration during deployment. When the DIP switch on both extenders is set to CO (factory default), auto CO/CPE negotiation will be triggered to automatically designate one device as the CO and the other as the CPE. This feature eliminates the possibility of human configuration errors and reduces deployment time.

Virtual panel and NMS monitoring for easy management

The managed DSL Ethernet extender is accessible via remote access using a web-based browser. The virtual panel (see Figure 3) provides device status information at a glance, and SNMP protocol support allows the DSL extender to be managed by Moxa's MXview network management software for total network manageability.

Link-quality LEDs for simple troubleshooting

Many factors can affect Ethernet extender transmission data rates, which can include manual transmission speed settings, distance, and environmental noise. Moxa's managed DSL extender displays DSL port link quality (speed/SNR) on the front panel (see Figure 4) for engineers/integrators to easily troubleshoot poor connectivity. A poor link quality may be indicative of a need to reconsider manually lowering transmission speed settings or investigate environmental noise levels. Furthermore, an inverse relationship exists between transmission distance and data transmission rate; as transmission distance increases, data transmission rate will diminish.

Link fault pass-through (LFP) for quick failure recovery

Moxa's DSL extender provides an LFP (link fault pass-through) feature to force a link-down status by disabling the downstream and upstream (or CO and CPE) Ethernet connections to prevent data loss. "STATE" LEDs (see Figure 5) indicate the location of the link failure, allowing network operators to immediately determine the location and quickly recover from a link failure. The LFP feature, when used in a network with Turbo Ring/Turbo Chain redundancy, can trigger redundancy recovery for the Ethernet port connection in less than 20 milliseconds, and less than 4 seconds if the DSL port connection fails.

Reduce deployment costs and total cost of ownership

The wide-temperature tolerance (-40 to 75°C) of the DSL extender is designed specifically for industrial applications such as ITS (intelligent transportation system), wayside control and monitoring, and factory automation. For applications with long distance transmission requirements, using Ethernet extenders can substantially reduce deployment costs and lower total cost of ownership, as illustrated in Figure 6 below.

Assuming that copper wiring exists between the locations, and the distance between the fiber and each traffic intersection is one mile, Moxa's DSL Ethernet extenders, based on the cost of USD$ 1,000 per Ethernet extender installation, can save this ITS application a total of USD$ 29,640 in deployment costs when compared to a fiber installation.

The Perfect DSL Extender Solution

Moxa's managed DSL Ethernet extenders offer two technologies to extend the point-to-point transmission over voice-grade copper wires, SHDSL and VDSL2, for different applications based on deployment distance and bandwidth requirements. The IEX-402-SHDSL series can provide data rates of up to 15.3 Mbps and a transmission distance of up to 8 kilometers, while the IEX-402-VDSL2 series (please contact Moxa for availability) is capable of reaching 100 Mbps (bi-directional) within 250 meters to fulfill high bandwidth requirements, such as HD video transmission, and a maximum transmission distance of up to 3 kilometers. Both models offer zero configuration for easy installation, virtual panel and NMS monitoring for easy management, link-quality LEDs for simple troubleshooting, and link fault pass-through (LFP) for quick failure recovery.

For more information on how Moxa's IEX-402-SHDSL series can cost-effectively extend your Ethernet connectivity, please visit http://www.moxa.com/product/IEX-402-SHDSL_Series.htm

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