Black Box Explains...RS-232.
RS-232, also known as RS-232C and TIA/EIA-232-E, is a group of electrical, functional, and mechanical specifications for serial interfaces between computers, terminals, and peripherals. The RS-232 standard was developed by... more/see it nowthe Electrical Industries Association (EIA), and defines requirements for connecting data communications equipment (DCE)—modems, converters, etc.—and data terminal equipment (DTE)—computers, controllers, etc.) devices. RS-232 transmits data at speeds up to 115 Kbps and over distances up to 50 feet (15.2 m).
The standard, which is functionally equivalent to ITU V.24/V.28, specifies the workings of the interface, circuitry, and connector pinning. Both sync and async binary data transmission fall under RS-232. Although RS-232 is sometimes still used to transmit data from PCs to peripheral devices, the most common uses today are for network console ports and for industrial devices.
Even though RS-232 is a “standard,” you can’t necessarily expect seamless communication between two RS-232 devices. Why? Because different devices have different circuitry or pinning, and different wires may be designated to perform different functions.
The typical RS-232 connector is DB25, but some PCs and other data communication devices have DB9 connectors and many newer devices have RJ-45 RS-232 ports. To connect 9-pin PC ports or RJ-45 to devices with 25-pin connectors, you will require a simple adapter cable. collapse
Product Data Sheets (pdf)...Pure Networking Media Converters
Compact Media Converter, 10BASE-T/10BASE2 Manual
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Black Box Explains...T1 and E1.
Product Data Sheets (pdf)...Modular Wireless Extenders for Digital or Analog I/O
If you manage a heavy-traffic data network and demand high bandwidth for high speeds, you need digital super-fast T1 or E1.
Both T1 and E1 are foundations of global communications. Developed... more/see it nowmore than 35 years ago and commercially available since 1983, T1 and E1 go virtually anywhere phone lines go, but theyre much faster. T1, used primarily in the U.S., sends data up to 1.544 Mbps; E1, used primarily in Europe, supports speeds to 2.048 Mbps. No matter where you need to connectNorth, South, or Central America, Europe, or the Pacific RimT1 and E1 can get your data there fast!
T1 and E1 are versatile, too. Drive a private, point-to-point line; provide corporate access to the Internet; enable inbound access to your Web Servereven support a voice/data/fax/video WAN that extends halfway around the world! T1 and E1 are typically used for:
• Accessing public Frame Relay networks or Public Switched Telephone Networks (PSTNs) for voice or fax.
• Merging voice and data traffic. A single T1 or E1 line can support voice and data simultaneously.
• Making super-fast LAN connections. Todays faster Ethernet speeds require the very high throughput provided by one or more T1 or E1 lines.
• Sending bandwidth-intensive data such as CAD/CAM, MRI, CAT-scan images, and other large files.
Basic T1 service supplies a bandwidth of 1.536 Mbps. However, many of todays applications demand much more bandwidth. Or perhaps you only need a portion of the 1.536 Mbps that T1 supplies. One of T1s best features is that it can be scaled up or down to provide just the right amount of bandwidth for any application.
A T1 channel consists of 24 64-kbps DS0 (Digital Signal [Zero]) subchannels that combine to provide 1.536 Mbps throughput. Because they enable you to combine T1 lines or to use only part of a T1, DS0s make T1 a very flexible standard.
If you dont need 1.536 Mbps, your T1 service provider can rent you a portion of a T1 line, called Fractional T1. For instance, you can contract for half a T1 line768 kbpsand get the use of DS0s 112. The service provider is then free to sell DS0s 1324 to another customer.
If you require more than 1.536 Mbps, two or more T1 lines can be combined to provide very-high-speed throughput. The next step up from T1 is T1C; it offers two T1 lines multiplexed together for a total throughput of 3.152 on 48 DS0s. Or consider T2 and get 6.312 Mbps over 96 DS0s by multiplexing four T1 lines together to form one high-speed connection.
Moving up the scale of high-speed T1 services is T3. T3 is 28 T1 lines multiplexed together for a blazing throughput of 44.736 Mbps, consisting of 672 DS0s, each of which supports 64 kbps.
Finally theres T4. It consists of 4032 64-kbps DS0 subchannels for a whopping 274.176 Mbps of bandwidththats 168 times the size of a single T1 line!
These various levels of T1 service can by implemented simulta-neously within a large enterprise network. Of course, this has the potential to become somewhat overwhelming from a management standpoint. But as long as you keep track of DS0s, you always know exactly how much bandwidth you have at your disposal.
T1s cousin, E1, can also have multiple lines merged to provide greater throughput. collapse
Product Data Sheets (pdf)...Crossover Media Converters Economy Crossover Media Converters
LinkGain 10/100BASE-TX to 100BASE-FX Media Converter Manual
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Product Data Sheets (pdf)...Single-Strand Fiber Media Converters
MultiPower Miniature Media Converter (10-/100-/1000-Mbps Copper to SFP) User Manual
User Manual for the LGC135A (Version 1)
Black Box Explains…Fiber Ethernet adapters vs. media converters.
When running fiber to the desktop, you have two choices for making the connection from the fiber to a PC: a fiber Ethernet adapter or a media converter like our... more/see it nowMicro Mini Media Converter.
Fiber Ethernet adapters:
Create no desktop clutter, but the PC must be opened.
Powered from the PC—require no separate power provision.
Require an open PCI or PCI-E slot in the PC.
Can create driver issues that must be resolved.
May be required in high-security installations that require a 100% fiber link to the desktop.
No need to open the PC but can create a cluttered look.
Powered from an AC outlet or a PC’s USB port.
Don’t require an open slot in the PC.
Plug-and-play installation—totally transparent to data, so there are no driver problems; install in seconds.
The short copper link from media converter to PC may be a security vulnerability. collapse