HOST NETWORK COMMUNICATION WITH TRANSPARENT CONNECTION DEVICES
 Inventors: Jeffrey A. Biber, Sterling, Va.;
Zon-Hong Hsieh, Potomac, Md.
 Assignee: Sprint International Communications Corp., Reston, Va.
 Appl. No.: 630,247
 Filed: Dec. 19, 1990
 Int. CI.5 H04L 12/56; H04J 3/24
 U.S. CI 370/94.1; 370/85.8;
 Field of Search 370/94.1, 60, 85.8,
370/95.2, 94.2, 94.3; 340/825.08; 371/32, 33
 References Cited
U.S. PATENT DOCUMENTS
4,755.992 7/1988 Albal 370/94.1
4,951,278 8/1990 Biber et al 370/94.1
4,975,905 12/1990 Mann et al 370/94.1
5,023,604 6/1991 Takase et al 370/94.1
Primary Examiner—Douglas W. Olms
Assistant Examiner—H. Kizou
Attorney, Agent, or Firm—Leitner, Greene &
A packet switched network has a system for providing an end-to-end connection for a communication or data transfer session between a host processor and a transparent connection device, which may be an unattended device, both utilizing a 3270 protocol. A terminal PAD is responsive to positive dataset signals on the associated line for the device indicating desire to establish communication by the device, irrespective of the absence of polling of the device by the host or by the terminal PAD, to transmit a call request packet through the network to a host PAD operatively associated with the host. The host PAD is responsive to the call request subsequent to a poll from the host to transmit call accept and circuit enable packets through the network to the terminal PAD. The latter then commences polling of the device to evoke information and data messages from the device for end-to-end communication with the host in the data transfer state. This procedure is followed only on start-up of the system, including start-up following a virtual circuit or other failure in the network so that the virtual circuit is automatically re-established even for unattended devices. At all other times after the start-up, communication is handled by local polling.
. 13 Claims, 13 Drawing Sheets