ConnNet

ConnNet was a packet switched data network operated by the Southern New England Telephone Company serving the U.S. state of Connecticut.

ConnNet was the nation's first local public packet switching network when it was launched on March 11, 1985. Users could access services such as Dow Jones News Retrieval, CompuServe, Dialcom, GEnie, Delphi, Eaasy Sabre, NewsNet, PeopleLink, the National Library of Medicine, and BIX. ConnNet could also be used to access other national and international packet networks, such as Tymnet and ACCUNET. Large companies also connected their mainframe computers to ConnNet allowing employees access to the mainframes from home. The network is no longer in operation.

Hardware

The X.25 network was based on hardware from Databit, Inc. consisting of three EDX-P Network Nodes that performed switching and were located in Hartford, New Haven and Stamford. Databit also supplied 23 ANP 2520 Advanced Network Processors each of which provided the system with a point of presence, a network control center and modems. Customers would order leased line connections into the network for host computers running at 4,800 to 56,000 bits per second (bit/s). Terminals would connect over a leased line from 1,200 to 9,600 bit/s synchronous, 300 to 2,400 bit/s asynchronous or using dial-up connections from 300 to 1,200 bit/s. The connection to Tymnet was established over an X.75 based 9,600 bit/s analog link from the ConnNet Hartford node to Tymnet's Bloomfield node.

Telnet - Current status

As of the mid-2000s, while the Telnet protocol itself has been mostly superseded for remote login, Telnet clients are still used, often when diagnosing problems, to manually "talk" to other services without specialized client software. For example, it is sometimes used in debugging network services such as an SMTP, IRC, HTTP, FTP or POP3 server, by serving as a simple way to send commands to the server and examine the responses.



This approach has limitations as Telnet clients speak is close to, but not equivalent to, raw mode (due to terminal control handshaking and the special rules regarding \377 and \15). Thus, other software such as nc (netcat) or socat on Unix (or PuTTY on Windows) are finding greater favor with some system administrators for testing purposes, as they can be called with arguments not to send any terminal control handshaking data. Also netcat does not distort the \377 octet, which allows raw access to TCP socket, unlike any standard-compliant Telnet software.



Telnet is popular with:

* enterprise networks to access host applications, e.g. on IBM Mainframes.
* administration of network elements, e.g., in commissioning, integration and maintenance of core network elements in mobile communication networks.
* MUD games played over the Internet, as well as talkers, MUSHes, MUCKs, MOOes, and the resurgent BBS community.
* embedded systems