Patent ID: 7307952

Claim:
A method for determining data flow restriction in a sender comprising: reading a Sequence Number field (SN) and a Data Offset (DO) from a Transmission Control Protocol (TCP) header in a data packet from the sender to a receiver; reading a Total Length field (TL) and an Internet Header Length field (IHL) from an Internet protocol (IP) header in the data packet from the sender to the receiver; reading an Acknowledgment Number field (AN) and a Window field (W) from a TCP header in a data packet from the from the receiver to the sender; and using the SN, DO, TL, IHL, AN and W from a network communication session to determine whether the sender restricts an amount of data flow, wherein said using comprises: calculating number of data bytes (DataSize) in the data packet using the TL, the IHL, and the DO; adding the DataSize to the SN to obtain a NextSequenceNumber; determining maximum NextSequenceNumber using TL, IHL, SN, and DO from at least one data packet from the sender to the receiver; determining maximum AN using AN from at least one data packet from the receiver to the sender; subtracting the maximum AN from the maximum NextSequenceNumber to obtain outstanding bytes (OutstandingBytes); subtracting the OutstandingBytes from W to obtain RemainingBytes; determining maximum W using the at least one data packet from the receiver to the sender; and calculating PercentWindowUsed using PercentWindowUsed=1-(RemainingBytes/maximum W).