Method and apparatus for programmable generation of traffic streams

• US 20060280124A1
• Filed: 08/25/2006
• Published: 12/14/2006
• Est. Priority Date: 07/31/2001
• Status: Active Grant

• Current Assignee: Xylon LLC (Intellectual Ventures LLC)
• Original Assignee: Null Networks LLC (Intellectual Ventures LLC)
• Inventors: Keller, Richard B., Denton, I. Claude
• Granted Patent: US 7,804,782 B2
• Time in Patent Office: Days
• US Class Current: 370/250
• CPC Class Codes: H04L 2012/5628 Testing
• CPC Class Codes: H04L 43/0811 by checking connectivity
• CPC Class Codes: H04L 43/0847 Transmission error
• CPC Class Codes: H04L 43/50 Testing arrangements
• CPC Class Codes: H04L 49/254 Centralised controller, i.e. arbitration or scheduling
• CPC Class Codes: H04L 49/30 Peripheral units, e.g. input or output ports
• CPC Class Codes: H04L 49/555 Error detection
• CPC Class Codes: H04L 69/22 Parsing or analysis of headers

Abstract

Methods and apparatus provide single or multi-port, flexible, cost-effective, built-in self-test capabilities for network communications equipment, such as for example switches, and programmably generate, and subsequently analyze, one or more sequences of test packets, wherein the test packets simulate at least two flows of traffic. Such test packets can have programmable headers, payloads, and duty cycle. A line card embodying the present invention may generate its own traffic pattern, which may be similar or identical, to traffic patterns observed on Internet backbones. These traffic patterns may contain a bimodal distribution of control packets interspersed with data packets wherein the control packets and data packets are relatively short and long respectively. A plurality of test packet generators/receivers can be deployed in a network communications device having a plurality of ports. In such a configuration, test generator/receiver is associated with each of the plurality of ports. Under software control, test packets can be sent from at least any one of the plurality of ports to at least any other one of the plurality of ports. In this way, an in-circuit testing procedure may be implemented without having to disconnect line cards from the switch and connect the switch to expensive external test equipment.

Claims

1-45. -45. (canceled)

46. A test packet generator comprising:

a first test generator element adapted to generate and transmit a synchronization packet and at least a first sequence including first and second test packets, each of said test packets including a header portion and a payload portion, said first test packet being separated from said second test packet by a first inter-packet gap;

a second test generator element adapted to receive the synchronization packet and the at least first sequence and to generate first and second expected test packets; and

a monitor element adapted to compare at least a portion of the first and second test packets received in the at least first sequence with at least an associated portion of the first and second expected test packets, respectively, and to indicate occurrence of a transmit error in response to any portion of said comparison of the test packets and the expected test packets resulting in a mismatch.

47. The test packet generator of claim 46, wherein the first test generator element is adapted to generate at least first and second sequences including the first and second test packets, said second test packet being followed by a second inter-packet gap, said first and second inteFpacket gaps exhibiting different lengths.

48. The test packet generator of claim 47, wherein the header of the first test packet is different from the header of the second test packet and wherein the first test packet comprises a length substantially representative of a data packet length and wherein the second test packet comprises a length substantially representative of a control packet length.