Conversion choices: as simple to install as patch cables and connectors, media converters function as physical layer devices and do not interfere with upper-level protocol information

Communications News, March, 2008

Media converters, among the simplest and perhaps most useful devices in the network infrastructure, change signals on a copper cable to signals that run on fiber-facilitating the use of fiber in the network. This capability comes in handy for budget-strapped IT managers who need to upgrade their systems from copper to fiber but do not have the financial or staffing resources for more-comprehensive upgrades.

Working on the physical layer of the network, media converters receive data signals from one media and convert them to another, while remaining invisible to data traffic and other net devices. These devices normally have two media-dependent interfaces and a power supply, and can be installed almost anywhere in a network.

As simple to install as patch cables and connectors, media converters function as physical layer devices and do not interfere with upper-level protocol information. This lets them support quality of service (QoS) and Layer 3 switching.

This month, Communications News looks at a representative sampling of the latest media converters from leading vendors.

TC Communications

Featuring high security, long-distance capability and rate control, the TC Communications Model TC3240 10/100M four-port switching/bridging fiber-optic Ethernet media converter converts or connects 10/100BASEe-TX (UTP) networks to 100BASE-FX (fiber-optic) networks. The TC3240 includes a built-in switch that enables distances up to 100 kilometers without additional hardware. It can be managed through any Web browser, SNMP, telnet or serial console.

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The TC3240 allows up to four different IP address aliases, manageable privilege levels for users and is password protected. Configuration settings can be stored and recovered to simplify network administration, and firmware can be remotely uploaded. Virtual LAN and network time protocol are supported. Rate control can be set in 32-Kbps increments. The TC3240 provides 10/100-Mbps autonegotiation and automatically adapts to full- or half-duplex mode.

Transition Networks

The MEF 9- and MEF 14-certified xBFFG media converters from Transition Networks deliver Ethernet private line and Ethernet virtual private line services. They are designed for customers that require the ability to remotely manage multiple Gigabit Ethernet media converters. IEEE 802.1q virtual LAN (VLAN) management, including double VLAN tagging and VLAN tunneling, supports network security and segmentation. Quality of service and a wide variety of link monitoring, troubleshooting and reporting features increase network performance.

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Digital diagnostics enable network administrators to measure the quality of the optical connection and report it over the operation, administrative and maintenance, and simple network-management protocol (SNMP) connections. Link-loss notification signals the fault to the management system IEEE802.1x and Radius enable user authentication and increase network security and ease of user management. The xBFFG product family can be managed via graphical user interface, as well as any Web browser, telnet or local serial command-line interface. The xBFFG product includes auto-negotiation, autocross, symmetrical or asymmetrical pause, bandwidth allocation, transparent link pass-through and automatic link restoration.

Electro Standards Laboratories

Fiber 485 HP fiber/RS-485 converters from Electro Standards Laboratories connect fiber-optic-linked terminals to a controller having an RS-485/RS-422 interface port. The RS-485 is a versatile communication standard that communicates over tong distances at fast data rates. This system offers full-duplex connection between two devices having RS-422 ports. Plus, the ports of the connected terminals are protected from damage by potential differences (ground variations) that exist between them. The Fiber 485 Model 4127 connects via a DB-15 connector; Model 4129 connects via an RJ-45 connector. These products convert RS-485/RS-422 serial communication interface to HP versatile link plastic core cable. The data transfer rate is greater than 20 Kbps.

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Aaxeon

Aaxeon's extended-range Optolinx media converters are available as standalone converters, 19" rack-mounted converters and DIN rail-mountable industrial media converters, all with both multimode and singlemode options. Also offered are managed and unmanaged solutions with optional support for Gigabit Ethernet. The FCU-100SC-S5, 50 km, is a singlemode fiber converter with a 50-kilometer range, while the FCU-100SC-S5 can extend to 80 kilometers.

These Fast Ethernet converters are compact units with metal cases to fulfill FCC emission standards. The converters feature LED diagnostics for power, activity, link and full-duplex/half duplex operation. All converters are fully compliant with the IEEE 802.3 and 802.3u Fast Ethernet standards and feature one STP-RJ-45 10/100BASETX port, as well as one fiber-optic 100BASEFX SC port. Each unit is powered by an external power supply.