Frame relay system capable of handling both voice and data frames

• US 5,303,237 A
• Filed: 07/31/1992
• Issued: 04/12/1994
• Est. Priority Date: 07/31/1992
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Bergman, William C., Cherukuri, Janakirama R.
• Primary Examiner(s): Olms, Douglas W.
• Assistant Examiner(s): HSU, ALPUS
• Application Number:
  US07/923,713
• Time in Patent Office: 620 Days
• Field of Search: 370/13, 370/17, 370/60, 370/60.1, 370/94.1, 370/94.2, 370/95.1, 370/105.1, 370/110.1, 370/85.6, 371/37.1, 371/37.7, 371/47.1
• US Class Current: 370/418
• CPC Class Codes: H04L 12/56 Packet switching systems
• CPC Class Codes: H04L 12/6418 Hybrid transport
• CPC Class Codes: H04L 2012/5635 Backpressure, e.g. for ABR
• CPC Class Codes: H04L 2012/5638 Services, e.g. multimedia, GOS, QOS
• CPC Class Codes: H04L 2012/5645 Connectionless
• CPC Class Codes: H04L 2012/5652 Cell construction, e.g. including header, packetisation, depacketisation, assembly, reassembly
• CPC Class Codes: H04L 2012/6464 Priority
• CPC Class Codes: H04L 2012/647 Frame Relay, X.25
• CPC Class Codes: H04L 2012/6481 Speech, voice

Abstract

Modifications to existing frame relay communication protocols are described which permit both voice and data frames to be handled in an integrated frame relay system. A Voice Frame Identifier bit is defined in the address field of a frame. When an intermediate node detects a voice frame, a CRC operation is performed using only the frame header; that is, voice information is excluded from the computation. The frame is flagged for priority processing in the node. When the intermediate node detects a data frame the CRC operation uses both the header and the data fields.

Claims

1. A frame relay communication system capable of transmitting both digital data frames and voice frames, said system comprising a plurality of nodes interconnected by communication links, at least one of said nodes including:

means for receiving a frame on an oncoming link;

means for detecting whether said frame is a digital data frame or a voice frame;

means responsive where said frame has been identified as a voice frame to perform an error checking operation only on a first set of fields of the frame, said first set of fields excluding data fields, said means being responsive to said frame having been identified as a data frame to perform an error checking operation on a second set of fields, said second set of fields including data fields.

2. A frame relay communication system as defined in claim 1 further including means responsive to a frame having been identified as a voice frame to further identify the frame as one which should be placed in a high priority output queue.

3. In a frame relay communication system comprising a plurality of nodes interconnected by communication links, a method of processing both digital data frames and voice frames in at least one node comprising the steps of:

receiving a frame from an incoming link;

identifying the frame as a voice frame or a data frame;

if the frame is a voice frame, performing an error check only on a first set of fields in the frame, said first set of fields excluding data fields; and

if the frame is a data frame, performing an error check on a second set of fields in the frame, said second set of fields including data fields.

4. A method as defined in claim 3 further including the step of identifying the frame as one which should be placed in high priority output queue where the frame has been identified as a voice frame.