Semiconductor memory based server for providing multimedia information on demand over wide area networks

• US 5,758,085 A
• Filed: 01/08/1997
• Issued: 05/26/1998
• Est. Priority Date: 08/23/1994
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Kouoheris, Jack Lawrence, Kumar, Manoj
• Primary Examiner(s): Coleman, Eric
• Application Number:
  US08/778,230
• Time in Patent Office: 503 Days
• Field of Search: 395/200.01, 395/200.61, 395/200.64, 370/255, 348/7
• US Class Current: 709/231
• CPC Class Codes: H04N 21/222 Secondary servers, e.g. proxy server, cable television Head-end provisioning of proxy services in data packet switching networks H04L67/56
• CPC Class Codes: H04N 21/23106 involving caching operations prefetching while addressing of a memory level in which the access to the desired data or data block requires associative addressing means within memory systems or architectures G06F12/0862; caching at an intermediate stage in a data network H04L67/568
• CPC Class Codes: H04N 7/147 Communication arrangements, e.g. identifying the communication as a video-communication, intermediate storage of the signals selecting H04Q
• CPC Class Codes: H04N 7/17336 Handling of requests in head-ends

Abstract

A method and apparatus for delivering multimedia video data from a server (host processor) to a plurality of clients connected to a communications network. More specifically, with this invention, preprocessed video and multimedia data packets are stored in switches of the network. When a client desires to receive the video and multimedia data, sends a request to the host processor which in turn sends a control message to the switches storing the requested data. These switches in turn send the requested data to the requesting client. If the data is not stored in the switches, the data must then be forwarded directly from the server to the requesting client.

Claims

1. A data communications network, comprising:

a. a communications system having a plurality of switches;

b. a host processor connected to the communications network;

c. a plurality of clients connected to the communications network;

d. each of the switches having

1) special memory means for storing preprocessed video packets,

2) means for retrieving and dispatching copies of requested ones of the preprocessed video packets to a requesting one of the clients, and

3) means for supplying information missing from the network protocol stack headers and trailers in the preprocessed packets,

said preprocessed video packets remaining stored in each of the switches even after copies of the requested video packets are transmitted to the requesting client

e. and means which enable each of the switches to independently transmit preprocessed video packets to clients.

2. A method for distributing video, multimedia or other continuous media content, from a particular switch of a number of switches, where said content is stored in form of preprocessed packets before or without a current request for said content, to clients, said switches and clients being part of a data communications system further comprising a host processor and other switches, said method comprising the steps:

1. requesting said content, or a portion thereof, by sending a request for transmission from one of said clients to said host processor,

4. A method as recited in claim 2, wherein each of said preprocessed packets comprises payload from said content, and headers and trailers of network protocol stack.

6. A method as recited in claim 4, wherein said content is removed from storage in said switch only if an independent control message requesting deletion of the said content is transmitted to latter said switch in said set, where said independent control message is independent of said request message.

3. identifying said particular switch in which the requested content is stored,transmitting a control message from said host processor to said switch, the control message indicating a request to send said content, or a portion thereof, from said switch to said one client, said control message not containing the requested content, or a portion thereof,transmitting a copy of the requested content, or a portion thereof, in form of preprocessed packets from said switch through one of the output ports of said switch to said one client, such that said continuous media content can be re-assembled from said preprocessed packets by said client, while retaining thereafter said content in the form of preprocessed packets in storage at said switch, said switch having switching means and several output ports enabling the switch to independently transmit content to any of said clients requesting said content, or a portion thereof.

5. A data communication system for transmitting video, multimedia or other continuous media content, from a switch where said content is stored in form of preprocessed packets before or without a current request for said content, to clients, said switch and clients being part of said data communications system which further comprises a host processor and;

1. means for requesting transmission of said content, or a portion thereof, by sending a request for transmission from one of said client to said host processor,

2. means for transmitting a control message from said host processor to said switch storing said requested content, the control message indicating a request to send said content, or a portion thereof, from said switch to said one of said clients, said control message not containing the requested content, or a portion thereof,

3. means for scheduling and transmitting a copy of the requested content, or a portion thereof, in form of preprocessed packets from said switch to said one of said clients, and

4. means enabling said switch which has switching means and several output ports to transmit content to any of said clients requesting said content, or a portion thereof, while retaining thereafter said content in the form of preprocessed packets in storage at said switch.

7. In a data communications system comprising a communications network to which a host processor, a plurality of switches and a plurality of clients are connected, a method of delivering continuous media content upon specific request by one of said clients, said content being stored in form of preprocessed packets at least in one of said switches, the method comprising:

1. transmitting a request message from a client requesting said continuous media content, or a portion thereof, to the host processor for a copy of the respective preprocessed packets which comprise said content to be delivered to the requesting client;

2. identifying the one of said plurality of switches in which said respective preprocessed packets are stored,

3. transmitting a control message from said host processor to said identified switch, said control message indicating a request to send said respective preprocessed packets from said switch to the requesting client, said control message not containing the requested content, or a portion thereof,

4. transmitting a copy of said respective preprocessed packets from said switch via one of its output ports through said network to said requesting client, while retaining thereafter said respective preprocessed packets in storage at said switch.

8. A data communications system for delivering continuous media content upon specific request by one of said clients, said system comprising a communications network to which a host processor, a plurality of switches and a plurality of clients are connected, said content being stored in form of preprocessed packets in one of said switches, said system further comprising:

1. means for transmitting a request message from the client requesting said continuous media content, or a portion thereof, to the host processor for a copy of the respective preprocessed packets which comprise said continuous media content to be delivered to the requesting client;

2. means for identifying the one of said plurality of switches in which said respective preprocessed packets are stored,

3. means for transmitting a control message from said host processor to said switch identified, said control message indicating a request to send respective preprocessed packets from said switch to the requesting client, said control message not containing the requested content, or a portion thereof,

4. means for transmitting a copy of said respective preprocessed packets from said switch via one of its output ports through said network to said requesting client, while retaining thereafter said respective preprocessed packets in storage at said switch.

9. System for distribution of continuous media content, having a host processor, a plurality of clients, and switches and/or routers having several output ports, said host processor comprising:

1. means for receiving requests from clients for transmission of a portion of said content stored in form of preprocessed packets,

2. means for identifying a particular switch or router in which the respective preprocessed packets comprising requested content are stored,

3. means for generating and transmitting a control message informing said particular switch or router that the transmission of said respective preprocessed packets is requested, said control message not containing the requested content, or a portion thereof, said switches and/or routers comprising

1. means for storing said continuous media content, segmented into preprocessed packets, in a media content memory,

2. means for receiving said control message from said host processor,

3. means for making a copy of said respective preprocessed packets in said media content memory,

4. means for scheduling and transmitting said copy of said specific preprocessed packets through one of the output ports of said switch or router to said particular client, while retaining thereafter said respective preprocessed packets in said media content memory.