Server controller responsive to various communication protocols for allowing remote communication to a host computer connected thereto

• US 5,857,074 A
• Filed: 08/16/1996
• Issued: 01/05/1999
• Est. Priority Date: 08/16/1996
• Status: Expired due to Term

• Current Assignee: Hewlett Packard Enterprise Development LP (Hewlett-Packard Enterprise Company)
• Original Assignee: Compaq Computer Corporation (HP Inc.)
• Inventors: Johnson, Derrick W.
• Primary Examiner(s): Meky, Moustafa M.
• Application Number:
  US08/695,827
• Time in Patent Office: 872 Days
• Field of Search: 395/200.31, 395/200.32, 395/200.47, 395/200.48, 395/200.49, 395/200.54, 395/200.57, 395/200.58, 395/200.33, 395/200.6, 395/200.61 , 395/200.62, 395/200.66
• US Class Current: 709/217
• CPC Class Codes: G06F 11/0709 in a distributed system consisting of a plurality of standalone computer nodes, e.g. clusters, client-server systems
• CPC Class Codes: G06F 11/0748 in a remote unit communicating with a single-box computer node experiencing an error/fault remote testing G06F11/2294
• CPC Class Codes: G06F 11/2294 by remote test
• CPC Class Codes: H04L 69/18 Multiprotocol handlers, e.g. single devices capable of handling multiple protocols
• CPC Class Codes: H04L 9/40 Network security protocols

Abstract

A communication system is presented whereby sequences of video screens sent from a host CPU to a video controller can be stored and subsequently retrieved by a terminal located remote from the host CPU. The host CPU and video controller form part of a server arranged within a distributed computing system. An administrator situated at the remote terminal can retrieve select video screens produced during server operations to determine information regarding the server configuration and possible causes of server failure or future failure. The sequence of video screens thereby represent video screen changes stored upon a server controller adapted for coupling to the server expansion bus. The video screen changes represent a sequence of video screen changes occurring prior to server failure or after server reset. Those changes provide beneficial information to an administrator located remote from the server, and allows the administrator to communicate with the server using several possible communication protocols. The server controller snoops display data written from the host CPU to the video controller and mirrors the display data upon buffers within the server controller. Information within the buffers can be called upon by a remotely situated administrator regardless of whether server power is lost in the interim.

Claims

1. A server controller, comprising:

a communication unit configured to receive information transferred following one of a plurality of communication protocols from a terminal located remote from the server controller;

a processor coupled to the communication unit, wherein the processor is responsive to at least one character which identifies one of said plurality of communication protocols; and

a controller memory coupled to the processor whereupon the processor, upon receiving said at least one character, dispatches video information stored within said controller memory.

2. The server controller as recited in claim 1, wherein said processor dispatches said video information to the terminal in response to identifying said one of the plurality of communication protocols.

3. The server controller as recited in claim 1, wherein said server controller is adapted for connection to a server.

4. The server controller as recited in claim 1, wherein said processor executes an interrupt service routine corresponding to each of said plurality of communication protocols.

5. The server controller as recited in claim 1, wherein said processor is responsive to said at least one character sent from said communication unit, and wherein said at least one character is forwarded to a plurality of state machines which determine which communication protocol of said plurality of communication protocols the terminal is currently forwarding.

6. The server controller as recited in claim 5, wherein the state machines determine whether the terminal is transferring information using text protocol, point-to-point (PPP) protocol, or pre point-to-point (pre PPP) protocol.

7. The server controller as recited in claim 5, wherein said state machines determines whether said at least one character transferred from the communication unit comprises three consecutive ASCII space characters, whether said at least one character transferred from the communication unit comprises a string of ASCII alphanumeric characters, or whether said at least one character transferred from the communication unit comprises a packet of binary values beginning with hexadecimal value 0x7E.

8. The server controller as recited in claim 7, wherein said ASCII space characters signify text protocol.

9. The server controller as recited in claim 7, wherein said ASCII alphanumeric characters comprise C, followed by L, followed by I, followed by E, followed by N, followed by T to signify pre point-to-point protocol.

10. The server controller as recited in claim 7, wherein said hexadecimal value signifies point-to-point protocol.

11. The server controller as recited in claim 1, wherein said communication unit comprises a modem.

12. A computer, comprising:

an expansion bus operably coupled between a host central processing unit and a video controller;

a server controller adapted for connection to said expansion bus for receiving display data upon said expansion bus, wherein said server controller comprises;

a communication unit coupled to receive information transferred following one of a plurality of communication protocols from a terminal located remote from the computer; and

a processor coupled to the communication unit for allowing storage of said display data to a controller memory and for allowing recall of said display data from the controller memory in response to the processor identifying said one of the plurality of communication protocols.

13. The computer as recited in claim 12, wherein said processor, upon receiving at least one character which identifies one of said plurality of communication protocols, dispatches video information stored within said controller memory.

14. The computer as recited in claim 12, wherein said processor dispatches said video information to the terminal in response to said one of the plurality of communication protocols.

15. The computer as recited in claim 12, wherein said processor sends at least one character to said host central processing unit based on the terminal sending information using one of the plurality of communication protocols.

16. The computer as recited in claim 12, wherein said server controller further comprises

detection logic coupled between said expansion bus and a controller bus;

said detection logic coupled to obtain mastership of said controller bus during a time in which display data is sent from the host central processing unit to the controller memory; and

said processor coupled to obtain mastership of said controller bus during a time in which at least one character is forwarded from the communication unit to the processor.

17. A method for servicing multiple communication protocols used to transfer information from a remote terminal, comprising:

providing a processor coupled to a communication unit accessible by a remote terminal;

transferring information using one of said multiple communication protocols from said remote terminal to said communication unit; and

activating state machines executed by said processor to recognize the one communication protocol being used.

18. The method as recited in claim 17, further comprising dispatching the recognized communication protocol to a controller memory for extracting a sequence of video screens stored therein.

19. The method as recited in claim 17, wherein said transferring companies providing information using either a text protocol, a PPP protocol or a pre-PPP protocol to said communication unit.

20. The method as recited in claim 17, wherein said activating comprises:

resetting said state machines;

initiating a timer; and

prior to said timer expiring, passing a character to said state machines to determine a type of communication protocol used to transfer information being received by said server controller.

21. The method as recited in claim 20, wherein said passing comprises determining whether said type of communication protocol is a text protocol, a PPP protocol, or a pre-PPP protocol.

22. The method as recited in claim 20, further comprising determining text protocol is used upon expiration of said timer.