Delay monitoring of telecommunication networks
First Claim
1. In a telecommunication network, a method of measuring delay parameters between nodes A and B, each having a clock, comprising steps of:
- node A sending to node B a measurement cell containing timestamp value T1 indicating the time the measurement cell is sent, according to the clock at node A;
node B, in response to the measurement cell, sending to node A a reporting measurement cell containing timestamp value T3 and a delay difference value Td, wherein Td=T2-T1, and T2 and T3 are respectively the times the measurement cell is received at node B and the reporting measurement cell is sent from node B according to the clock at node B;
node A receiving the reporting measurement cell at time T4, according to the clock at node A, and obtaining a cell delay variation CDV in the direction from node A to node B as one of the delay parameters by using the following equation;
space="preserve" listing-type="equation">CDV=Td-most recent minimum Td.
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Abstract
Novel techniques are disclosed for continuously monitoring parameters of delay between two nodes in a telecommunication network such as an ATM or frame relay network. The techniques use measurement cells, i.e. test cells, test frames, performance management ATM OAM cells, or performance management frame relay frames. These cells or frames contain a timestamp indicating the time a cell or frame is sent and a delay value indicating a difference between reception and transmission times of the cell or frame. Near-end and far-end as well as unidirectional or bidirectional monitoring can be performed, to support single-ended monitoring.
185 Citations
10 Claims
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1. In a telecommunication network, a method of measuring delay parameters between nodes A and B, each having a clock, comprising steps of:
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node A sending to node B a measurement cell containing timestamp value T1 indicating the time the measurement cell is sent, according to the clock at node A; node B, in response to the measurement cell, sending to node A a reporting measurement cell containing timestamp value T3 and a delay difference value Td, wherein Td=T2-T1, and T2 and T3 are respectively the times the measurement cell is received at node B and the reporting measurement cell is sent from node B according to the clock at node B; node A receiving the reporting measurement cell at time T4, according to the clock at node A, and obtaining a cell delay variation CDV in the direction from node A to node B as one of the delay parameters by using the following equation;
space="preserve" listing-type="equation">CDV=Td-most recent minimum Td. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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Specification