Precise statistics computation for communication networks
A method for accurately measuring one or more network performance statistics during one or more sampling periods comprises processing a received data packet to identify flow information and time of arrival; transmitting the data packet, along with metadata comprising the flow information and the time of arrival, to a sample processing module; replaying the reception of the data packet based on the relative speed of the transmission link and the databus and the time of arrival; incrementing a number of bytes received for the data packet for a first sampling period; starting a second sampling period at a predetermined time and incrementing a number of bytes received for the data packet for the second sampling period, if the replaying is not completed. The number of bytes received for the data packet for the first and second sampling periods are processed into first and second sampling period statistics, respectively.
1. A method, comprising:
receiving a data packet at a network interface of a network device from a transmission link;
processing said data packet to identify flow information and a time of arrival;
transmitting over a databus a copy of said data packet, along with metadata comprising said flow information and said time of arrival, to a sample processing module;
replaying reception of said data packet at the sample processing module based on said time of arrival and a relative speed of the transmission link and the databus,
incrementing a first number of bytes received for the copy of said data packet for a first sampling period;
incrementing a second number of bytes received for the copy of said data packet in a second sampling period;
determining a total byte count from said first number of bytes received for the copy of said data packet for said first sampling period and said second number of bytes received for the copy of said data packet for said second sampling period;
determining network performance statistics based on the total byte count;
wherein the total byte count and the network performance statistics are determined when the copy of said data packet is completely received by the sample processing module.
2. The method of claim 1 wherein said determining network performance statistics is done based on the flow information, packet size of the data packet, the time of arrival, and speed of the transmission link.
3. The method of claim 1 wherein said determining network performance statistics is done within the network device.
4. The method of claim 1 wherein said determining network performance statistics is done remotely from the network device.
5. The method of claim 1 wherein at least one of the network performance statistics is determined within the network device and at least one of the network performance statistics is remotely from the network device.
6. A system for measuring one or more network performance statistics during one or more sampling periods, comprising:
a network interface at a network device for receiving a data packet via a transmission link;
a module coupled with said network device for processing said data packet to identify flow information and a time of arrival, and for transmitting over a databus a copy of said data packet, along with metadata comprising said flow information and said time of arrival;
a sample processing module configured for replaying reception of said data packet based on said time of arrival and a relative speed of the transmission link and the databus, and for incrementing a first number of bytes received for the copy of said data packet for a first sampling period, and incrementing a second number of bytes received for the copy of said data packet for a second sampling period;
said sample processing module configured to determine a total byte count from said first number of bytes and said second number of bytes, and configured to determine network performance statistics based on the total byte count;
wherein the total byte count and the network performance statistics are determined when the copy of said data packet is completely received by the sample processing module.
7. The system of claim 6 wherein said sample processing module is configured to determine the network performance statistics based on the flow information, packet size of the data packet, the time of arrival, and speed of the transmission link.
8. The system of claim 6 wherein said sample processing module is coupled to the network device, whereby the determining network performance statistics is done within the network device.
9. The system of claim 6 wherein said sample processing module is remote from the network device, whereby the determining network performance statistics is done remotely from the network device.
10. The system of claim 6 wherein said sample processing module is coupled to the network device, whereby determining at least one of the network performance statistics is done within the network device; and further comprising a remote sample processing module remote from the network device, whereby determining at least one of the network performance statistics is done remotely from the network device.