Flow control in a packet-switched communication network using a leaky bucket algorithm
OwnerPetri Gronberginventor
Life of this patent
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Abstract
A buffer in a packet control network unit may overflow or underflow during data transmission from an external network to a user terminal, thus causing many kinds of problems in data transmission. The problems can be prevented in a packet network providing a data flow control algorithm performed by the packet control unit. The packet control unit indicates to the network node, from which it receives data packets, the actual transmission rate of a specified data flow, as well as the buffering capacity for that flow. Then the said network node adjusts its transmission rate for the indicated flow.
Claims15
A method of controlling data flow in a packet network comprising
- a first network node in which initial flow control parameters are stored and through which data packets are transferred to a second network node,
- the second network node, in which data packets are stored in a buffer before being forwarded towards their destinations,
- characterized by the steps of:
- in the second network node,
- monitoring the transmission rate of each of a plurality of data flows, each data flow being formed by the packets destined for a certain destination,
- monitoring the degree of filling in buffers associated with each of the data flows,
- computing flow control parameter values for each of the data flows based on the transmission rate of the data flow and the degree of filling in the buffer,
- sending to the first network node a flow control message which includes an identifier and the flow control parameter values of a data flow, and
- in the first network node,
- receiving the flow control message and replacing previous flow control parameter values with the new values received,
- adjusting the data rate for the data flow based on information in the flow control message, and
- transferring data from the first network node to the second network node at the adjusted data rate.
A system for controlling data flow in a packet network comprising
- a first network node in which initial flow control parameters are stored and through which data packets are transferred to a second network node,
- a second network node, in which data packets are stored in a buffer before being forwarded towards their destinations,
- characterized in that the system includes
- in the second network node,
- first monitoring means for monitoring the transmission rate of the plurality of data flows, each data flow being formed by the packets destined for a certain destination,
- second monitoring means for monitoring the degree of filling in buffers associated with each of the data flows,
- computing means for computing flow control parameter values for each of the data flows based on the transmission rate of the data flow and the degree of filling in the buffer,
- sending means for sending to the first network node a flow control message which includes an identifier and the flow control parameter values of a data flow, and
- in the first network node,
- receiving means for receiving the flow control message and replacing previous flow control parameter values with the new values received,
- adjusting means for adjusting the data rate for the data flow based on information in the flow control message, and
- transferring means for transferring data from the first network node to the second network node at the adjusted data rate.
Dependencies are inferred from the claim text.