System and method for improved data transfer in packet-switched communication networks

In a communication network that implements TCP connections between at least one sender node and at least one receiver node utilizing sliding-window flow control, a method of performing retransmission timer based error recovery at a sender node, comprising the steps of:

• (a) opening a TCP connection between the sender node and a receiver node;
• (b) initializing a retransmission timer (REXMT) with a predetermined retransmission timer value (RTO)
• (c) transmitting data segments from the sender node to the receiver node;
• (d) receiving acknowledgement (ACK) segments from the receiver node;
• (e) upon receipt of each ACK segment from the receiver node, determining a (RTO) as a function of the time required for the sender node to receive a predetermined number of duplicate acknowledge segments (DUPACKS) from the receiver node;
• and
• (1) reinitializing said REXMT with said RTO.

A method of operating a packet-switched communications network that implements logical connections between sender nodes and receiver nodes on the network, wherein said sender nodes are configured to utilize sliding-window flow control and retransmission timer based error recovery, comprising the steps of:

• (a) establishing logical connections between said sender nodes and respective receiver nodes on the network;
• (b) initializing, for a logical connection, a retransmission timer with a retransmission timer value that is a function of network traffic parameters;
• (c) transmitting data packets from sender nodes to respective receiver nodes on the network;
• (d) receiving, at the sender nodes, acknowledgement packets from their, respective receiver nodes;
• and
• (e) upon receipt of an acknowledgement packet, reinitializing said retransmission timer (REXMT) with a retransmission timer value (RTO) that is determined as a function of the time required for the sender node to receive a predetermined number of duplicate acknowledge segments (DUPACKS) from the receiver node.

A communications network element that implements TCP connections between at least one sender node and at least one receiver node utilizing sliding-window flow control and REXMT based error recovery, comprising:

• (a) an output module for transmitting data segments to a receiver node;
• (b) an input module for receiving acknowledgement (ACK) segments from the receiver node;
• and
• (c) logic, operating on a processor associated with the network element, for reinitializing said retransmission timer (REXMT) with a retransmission timer value (RTO) that is determined at a function of the time required for the sender node to receive a predetermined number of duplicate acknowledge segments (DUPACKS) from the receiver node.

A communications network sender node that implements TCP connections with at least one receiver node utilizing sliding-window flow control and retransmission timer based error recovery, comprising:

• (a) means for opening a TCP connection between the sender node and a receiver node;
• (b) means for initializing a REXMT with a predetermined RTO;
• (c) means for transmitting data segments from the sender node to the receiver node;
• (d) means for receiving ACK segments from the receiver node;
• and
• (e) means for reinitializing said retransmission timer (REXMT) with a retransmission timer value (RTO) that is determined as a function of the time required for the sender node to receive a predetermined number of duplicate acknowledge segments (DUPACKS) from the receiver node.

A sender node in a packet-switched communications network that implements logical connections between sender nodes and receiver nodes on the network, wherein sender nodes are configured to utilize sliding-window flow control and retransmission timer based error recovery, comprising:

• (a) means for establishing logical connections between sender nodes and respective receiver nodes on the network;
• (b) means for initializing, for a logical connection, a retransmission timer with a retransmission timer value that is a function of network traffic parameters;
• (c) means for transmitting data packets from sender nodes to respective receiver nodes on the network;
• (d) means for receiving, at the sender nodes, acknowledgment packets from their respective receiver nodes;
• and
• (e) means for reinitializing said retransmission timer (REXMT) with a retransmission timer value (RTO) that is determined as a function of the time required for the sender node to receive a predetermined number of duplicate acknowledge segments (DUPACKS) from the receiver node.