The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 31, 1991
Filed:
Nov. 21, 1990
Carl J Bushue, Olathe, KS (US);
Theodore S Holdahl, Lake Quivira, KS (US);
Sprint International Communications Corp., Reston, VA (US);
Abstract
A method and apparatus for providing troubleshooting capability in a four wire telephone line employing a V.32-type or other unbalanced modem in a local communication link at one or both ends of the telephone line for a data network. Each modem has its own transmitter and receiver. An activatable but normally inhibited analog loopback is installed externally of the modem within the local link with which the modem is associated, with no loopback connection between the transmitter and the receiver within the modem itself. The external loopback is activated while the modem is induced to transmit a call connection signal, so that by virtue of the external loopback the signal is fed back to the receiver of the same modem to permit testing of the operativeness of the modem and the related portion of the link. The external loopback may be activated from terminal equipment on the local link with which the modem is associated, or may be activated from a point of the network remote from the local link.