The Problem
Today, many private lines still exist that use antiquated modems connected to a leased line. Because IP networks have become ubiquitous, many private lines and their associated modems can be eliminated, and the traffic sent over the Internet or a company’s own private internet network. In some cases, with the growth of the ubiquity of IP-based applications running on PC’s, larger hosts and servers, what is needed is no longer a private line but a single device at the outer edge of an internet that mediates from IP to the native protocol being used by the attached end device.
The major problems with the private line circuits are that the modems are old, use old technology, are constantly failing, and costly to maintain. In addition, there are usually monthly charges for use of the line. Also, where ground plane isolation is required, the modems used must have this as a feature. Depending on what protocols are being handled, different types of modems are needed. For synchronous protocols, synchronous modems are required, for asynchronous protocols, asynchronous modems are required. Typically, the modems on each end should be the same models from the same manufacturer. Depending on their age, they may need to be physically strapped or have switches set before installation.
A Solution
In the figure above, the modems and private line have been eliminated. Instead, a Datatek DT-9480 is used as an access point to the IP network and as shown in the figure paired with a port on a Datatek DT-4284 on the other end of the network. The DT-9480 is a multi-protocol device that mediates and/or terminates legacy protocols for interface with an IP network. It has a single DB25 RS-232 port and one 10/100 BaseT Ethernet port. The DT-4284 has four RJ45 RS-232 user ports and one 10/100 BaseT Ethernet port. Each port of a DT-4284 has the same capabilities as the DT-9480. However, each DT-4284 user port is independent of the other user ports, so each port can be running its own configured protocol and at its own desired speed.
The DT-9480 and DT-4284 ports are configured with the OSI layer 2 protocol used on the private line previously, such as asynchronous for async circuits or HDLC for synchronous circuits, for example. The speed is configured but can be easily changed remotely if the physical port on the connected device has the capability of running at a higher speed than what was possible previously with the modem connected. No ground plane issues exist because Ethernet is being used. Archaic private modem circuits and their associated maintenance support and troubleshooting are eliminated. The traffic is now transported over the IP cloud.
Benefits of this Solution
This solution provides the following benefits:
1. Provides seamless migration for the protocols handled over the circuits
2. Is cost effective
3. Is efficient
4. Is simple to install and operate.
5. Can be remotely configured or reconfigured after installation.
6. Provides isolated ground planes
7. Uses the existing IP network infrastructure for transport
8. Is reliable and has a low failure rate.
9. Provides optional data encryption
10. Supports various speeds and physical layer interfaces
11. Supports optional Closed User Group (CUG) security
For additional detail and other scenarios, click here for more information on our IP Modem solution .
