Back to results
US 5,477,531 AGranted
Method and apparatus for testing a packet-based network
AssigneeHewlett-Packard Company
InventorsNeil H. McKee, Peter Phaal
Life of this patent
Estimating the term…
Loading patent…
Loading patent…
AssigneeHewlett-Packard Company
InventorsNeil H. McKee, Peter Phaal
Estimating the term…
In packet-based networks (10), it is often desired to test communications between two specific stations (11, 12). This can generally be effected from a first one of the stations (11) by requesting the other station (12) to `loop-back` a test packet sent from the first station. The first station (11), on receiving back the test packet, can thereby ascertain that not only is communication with the other station (12) possible, but it can also measure the round trip time. However, more complex characteristics of the transmission path between the stations (11, 12) are not ascertainable in this manner. The transmission of a predetermined sequence of packets permits such characteristics to be determined by observing the effect of the network (10) on the sequence considered as a whole. Thus by varying packet size in a sequence, characteristics such as bandwidth, propagation delay, queuing delay and the network's internal packet size can be derived. The use of bursts of packets enables buffer size and re-sequencing characteristics to be determined.
A method of testing a packet-based network to ascertain characteristics of packet transmission between first and second nodes on the network, said method comprising the steps of transmitting packets between said first and second nodes;
A method according to any one of the preceding claims, wherein said packets are transmitted from said first node and looped-back at said second node for reception at said first node, said correlation data being derived by comparing packet transmission and reception at said first node.
Apparatus for testing a packet-based network to ascertain characteristics of packet transmission between first and second nodes on the network, said apparatus comprising transmission means for transmitting packets between said first and second nodes, receiving means for receiving the packets of one of said nodes, and correlation means for correlating packet transmission and reception to derive correlation data indicative of a first of said packet transmission characteristics;
Dependencies are inferred from the claim text.