Synchronous packet voice/data communication system

• US 4,819,228 A
• Filed: 10/15/1987
• Issued: 04/04/1989
• Est. Priority Date: 10/29/1984
• Status: Expired due to Term

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: StrataCom, Inc. (Cisco Systems, Inc.)
• Inventors: Owen, David P., Baran, Paul, Holden, Brian D., Stonebridge, Peter W. J., Corbalis, Charles M., Masatsugu, Jon K., Marggraff, Lewis J.
• Primary Examiner(s): NOT, DEFINED
• Assistant Examiner(s): Scutch, III, Frank M.
• Application Number:
  US07/109,337
• Time in Patent Office: 537 Days
• Field of Search: 370/60, 370/54, 370/85, 370/118, 370/110.1, 340/825.5
• US Class Current: 370/389
• CPC Class Codes: H04L 12/64 Hybrid switching systems
• CPC Class Codes: H04M 7/006 Networks other than PSTN/ISDN providing telephone service, e.g. Voice over Internet Protocol (VoIP) , including next generation networks with a packet-switched transport layer H04L65/00 takes precedence; aspects not specific to the type of network H04M3/00; special services in those networks H04M3/42
• CPC Class Codes: H04Q 2213/13031 Pulse code modulation, PCM
• CPC Class Codes: H04Q 2213/13034 A/D conversion, code compression/expansion
• CPC Class Codes: H04Q 2213/1309 Apparatus individually associated with a subscriber line, line circuits
• CPC Class Codes: H04Q 2213/13096 Digital apparatus individually associated with a subscriber line, digital line circuits
• CPC Class Codes: H04Q 2213/13103 Memory
• CPC Class Codes: H04Q 2213/13174 Data transmission, file transfer
• CPC Class Codes: H04Q 2213/13196 Connection circuit/link/trunk/junction, bridge, router, gateway
• CPC Class Codes: H04Q 2213/13201 Change-over of service during connection
• CPC Class Codes: H04Q 2213/13216 Code signals, frame structure
• CPC Class Codes: H04Q 2213/1322 PBX
• CPC Class Codes: H04Q 2213/13292 Time division multiplexing, TDM
• CPC Class Codes: H04Q 2213/13299 Bus

Abstract

A packet communications network and apparatus for communicating information in voice and data packets transmits and receives voice and data in accordance with standardized frames of a standardized communications format such as a standard DS-1 type trunk. An apparatus is coupled to multiplex standardized channels into a single channel wherein voice or data signals are packetized into independently addressable packets synchronized on, for example, the DS-1 frame. The network includes voice and packet data concentration apparatus operable in a multiple node trunk environment to concentrate signals into independently addressable synchronously switchable packets, thereby to provide an efficient (high data capacity) interface between trunk terminations. Up to four times as much information can be transferred between nodes with the ability to switch between nodes as compared to conventional TDM and PCM communication without compression without the ability to switch between nodes.

Claims

1. For use in a communications network for communicating data and voice in independent information packets, including voice packets and data packets, through a digital communications medium, an apparatus for coupling digital signals to said communications medium comprising:

a multiplexing bus, said multiplexing bus including a clock line for synchronizing said information packets;

a multiplexing bus controller coupled to said multiplexing bus and operative to generate at least a clock signal on said clock line to control switching of said information packets, said information packets comprising independently addressable digital data conforming to a standardized time frame of a standardized synchronous communications format; and

means coupled to said multiplexing bus for packetizing signals into digitized information packets, each said digitized information packet having a packet format which is self-contained as to destination and content and which conforms to boundaries of said standardized synchronous time frame; and

first digital communications means coupled to said multiplexing bus for transmitting said information packets to a digital communication medium and for receiving said information packets from said digital communications medium, said first digital communication means being operative to communicate said information packets according to said standardized communication format.

2. The apparatus according to claim 1, further including means coupled to said multiplexing bus for compressing voice signals and for decompressing voice signals.

3. The apparatus according to claim 1, further including at least one packet framing transceiver for receiving and transmitting digitized information packets according to said standardized communications format, and means coupling said packet transceiver to said communications medium, said packet transceiver further including means for coupling address timing and information signals to said multiplexing bus.

4. The apparatus according to claim 3 wherein said packet transceiver comprises:

means for inserting framing and signaling information into a standardized time frame in said standardized communications format; and

means for extracting framing and signaling information from a standardized time frame in said standardized communication format.

5. The apparatus according to claim 4 wherein said packet framing transceiver further includes means coupled to said multiplexing bus for receiving and serially forwarding said information packet, and means coupled to said multiplexing bus for transferring TDM signals.

6. The apparatus according to claim 1 wherein said packet control unit includes:

a packet receiver coupled to said multiplexing bus;

a packet transmitter coupled to said multiplexing bus; and

a multiplexing bus controller coupled to said multiplexing bus for controlling operation of said multiplexing bus.

7. The apparatus according to claim 1 wherein said standardized communication format is a DS-1 trunk communication format having a 193 bit frame and wherein each said information packet has a format comprising an 168 bit data packet field and 24 bit address and error correction field, said packet format being confined to one information packet per standardized frame.

8. The apparatus according to claim 7 wherein said information packet employs a four bit voice code in normal operation.

9. The apparatus according to claim 2 wherein said voice packets are dropped in the event of over capacity operation of said communication medium.