Powerline network bridging congestion control
View Patent ↗In a powerline network, a power line node device coupled to a host bridge application detects a “jam packet” in response to an attempt to pass a frame to the host bridge application. The powerline node device uses internal logic to override a conventional ARQ response to this and subsequent frames, in particular, when such frames are of the type for which a response is expected, with an automatic FAIL response for a predetermined time interval.
1. A method of performing flow control in a network, comprising: a node in a network of nodes detecting receipt of a jam-indicating packet from a bridge device in response to an attempt by the node to transmit a frame to the bridge device, wherein the jam-indicating packet has a generally unique content that is recognizable by nodes as an indication that a device on the network is congested and requests that it not be sent further packets; in response to detection of the jam-indicating packet by the node, causing a fail response to be transmitted by the node to the network for the frame; and for a predetermined time interval after the detection, causing another fail response to be transmitted by the node to the network for any subsequent frames transmitted by any of the other nodes when such frames are of the type for which a response is expected, wherein the fail response transmitted in response to receipt of the jam-indicating packet is the same fail response ordinarily transmitted, at times other than when a device on the network is congested, to indicate that a frame has not been received because of insufficient resources, wherein the network is a powerline network, and the fail response is transmitted to the powerline network.
2. The method of claim 1 , wherein causing comprises:
asserting a fail response override signal when the receipt of the jam-indicating packet is detected;
setting a fail response override timer to time the predetermined time interval; and
de-asserting the fail response override signal upon expiration of the fail response override timer.
3. The method of claim 2 , wherein causing further comprises:
determining if a frame transmitted by one of the nodes is a unicast frame for which a response is expected; and
determining if the fail response override signal is asserted.
4. The method of claim 3 , wherein causing further comprises:
if it is determined that the frame is a unicast frame for which a response is expected and that the fail response override signal is asserted, transmitting a fail response.
5. The method of claim 3 , wherein causing further comprises:
otherwise, sending a response in accordance with ARQ protocol.
6. The method of claim 1 , wherein the network of nodes is a powerline network.
7. The method of claim 6 , wherein the nodes in the network of nodes operate according to HomePlug 1.0 Specification protocols.
8. The method of claim 1 , wherein the jam-indicating packet is received over a Media Independent Interface bus.
9. The method of claim 1 , wherein the bridge device comprises a host computer that executes a bridge application.
10. A computer program residing on a non-transitory computer-readable medium for performing flow control in a network, the computer program comprising instructions causing a node in a network of nodes to: detect receipt of a jam-indicating packet from a bridge device in response to an attempt by the node to transmit a frame to the bridge device; wherein the jam-indicating packet has a generally unique content that is recognizable by nodes as an indication that a device on the network is congested and requests that it not be sent further packets; in response to detection of the jam-indicating packet by the node, cause a fail response to be transmitted by the node to the network for the frame; and for a predetermined time interval after the detection, cause another fail response to be transmitted by the node to the network for any subsequent frames transmitted by any of the nodes when such frames are of the type for which a response is expected, wherein the fail response transmitted in response to receipt of the jam-indicating packet is the same fail response ordinarily transmitted, at times other than when a device on the network is congested, to indicate that a frame has not been received because of insufficient resources, wherein the network is a powerline network, and the fail response is transmitted to the powerline network.
11. A system comprising: a jam-indicating packet detector at a node in a network of nodes for detecting receipt of a jam-indicating packet from a bridge device in response to an attempt by the node to transmit a frame to the bridge device;
wherein the jam-indicating packet has a generally unique content that is recognizable by nodes as an indication that a device on the network is congested and requests that it not be sent further packets;
means, responsive to detection of a jam-indicating packet by the jam-indicating packet detector, for causing a fail response to be transmitted by the node to the network for the frame;
for a predetermined time interval after the detection, means for causing another fail response to be transmitted by the node to the network for any subsequent frames transmitted by any of the nodes for a predetermined time interval when such frames are of the type for which a response is expected,
wherein the fail response transmitted in response to receipt of the jam-indicating packet is the same fail response ordinarily transmitted, at times other than when a device on the network is congested, to indicate that a frame has not been received because of insufficient resources, wherein the network is a powerline network, and the fail response is transmitted to the powerline network.