Electrical computers and digital processing systems: multicomput – Master/slave computer controlling – Master/slave mode selecting
Reexamination Certificate
1997-05-19
2001-02-20
Dinh, Dung C. (Department: 2757)
Electrical computers and digital processing systems: multicomput
Master/slave computer controlling
Master/slave mode selecting
C709S222000
Reexamination Certificate
active
06192397
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to the field of data communications. In particular, the present invention provides a system for establishing a master-slave relationship, at the physical layer, on a point-to-point link in a peer-to-peer network.
2. Background
Peer-to-Peer networks utilize a communication protocol such as Carrier Sense Multiple Access/Collision Detection (CSMA/CD). The philosophy of this type of network is that every device coupled to the network determines, on an independent basis, when to send information to another device coupled to the network. To summarize this process, when a device has data for transmission to another device on the network, the device checks the medium across which it intends to transmit the data for any existing traffic. If the device senses traffic on the medium, it waits until the medium is free of traffic before initiating transmission of its data. If the device does not sense traffic on the medium, then it attempts to send data across the network to the other device. If the sending device detects a collision during the transmission, it suspends transmission and waits a randomly chosen amount of time before attempting to resend the data by repeating the above process.
As the utilization of a peer-to-peer network increases, the number of collisions on the network increases, thereby reducing the overall throughput of the network. To address this problem, technology has developed various types of hardware capable of higher data transmission rates and has developed more efficient network software. Higher data transmission rates reduce the time period during which the data is on the medium for a given amount of data, thereby reducing the probability of a collision with data from another device.
Network software typically includes several layers of protocol. For example, in an Ethernet local area network, the network interface comprises: the physical layer, the media access control sublayer and the logical link control sublayer. The physical layer's function is to take data packets given to it from the media access control layer and place the packets on the medium to be delivered to a destination device. The carrier sense, collision detection functions to support the arbitration of access to the medium by the attached device.
Each device in a peer-to-peer network is a peer to other devices in the network. Thus, no device is considered to be “superior” to any other device on the network. As such, a master-slave relationship between devices is not typically supported in a peer-to-peer network environment. It is therefore desirable to provide a system capable of establishing a master-slave relationship (when such need arises), at the physical layer, on a point-to-point link in a peer-to-peer network.
SUMMARY OF THE INVENTION
The present invention provides improved performance in a peer-to-peer network by permitting the establishment of a master-slave relationship between any two devices at each end of a point-to-point link. By establishing a master-slave relationship, the master may provide control signals or other data to the slave for use by the slave.
An embodiment of the present invention provides a system for establishing a master-slave relationship at the physical layer between a first device and a second device in a peer-to-peer network connected by a point-to-point link. The system generates a first information which is associated with the first device. Additionally, a second information is generated which is associated with the second device. The first information is compared with the second information to generate a comparison result. Based on the comparison result, one device is designated as a master and the other device is designated as a slave.
Another feature of the invention provides that the generation of the first information and the second information is performed by the first device and second device, respectively.
A specific aspect of the invention transmits the first information from the first device to the second device and transmits the second information from the second device to the first device. Each device then compares the first information to the second information to determine which device is master and which device is slave. Since each device has the same data and the same criteria, their determination is expected to agree.
An embodiment of the invention assigns a particular value to each device. If the assigned values are unequal, then the assigned values are used to determine which device is master and which device is slave. If the assigned values are equal, then the first device selects a first random number and the second device selects a second random number. The first selected number is compared with the second selected number to generate a comparison result. Based on the comparison result, one device is designated as master and the other device is designated as slave.
REFERENCES:
patent: 4488232 (1984-12-01), Swaney et al.
patent: 4543574 (1985-09-01), Takagi et al.
patent: 4630264 (1986-12-01), Wah et al.
patent: 5729686 (1998-03-01), Heck et al.
Blakely , Sokoloff, Taylor & Zafman LLP
Dinh Dung C.
Nortel Networks Limited
LandOfFree
Method for establishing a master-slave relationship in a... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method for establishing a master-slave relationship in a..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method for establishing a master-slave relationship in a... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2613422