Resilient data communications with physical layer link aggregation, extended failure detection and load balancing
Rapid channel failure detection and recovery in wireless communication networks is needed in order to meet, among other things, carrier class Ethernet channel standards. Thus, resilient wireless packet communications is provided using a physical layer link aggregation protocol with a hardware-assisted rapid channel failure detection algorithm and load balancing, preferably in combination. This functionality may be implemented in a Gigabit Ethernet data access card with an engine configured accordingly. In networks with various topologies, these features may be provided in combination with their existing protocols.
1. A method of detecting a transmit status and a receive status of a receiving node of a wireless link of multiple wireless links in a wireless link aggregation group, comprising:
(a) detecting by a receiving node whether a first packet was received from a transmitting node over the wireless link, the wireless link at the receiving node having a transmit status and a receive status;
(b) if the first packet has not been received by the receiving node from the transmitting node over the wireless link, then
(1) computing a time interval since last receipt of any packet from the transmitting node over the wireless link;
(2) comparing the time interval against a time interval threshold; and
(3) if the time interval fails a condition relative to the time interval threshold, then setting the receive status of the wireless link at the receiving node to ‘bad’;
(c) if the first packet has been received by the receiving node from the transmitting node over the wireless link, then
(1) computing at a physical layer an integrity value of the first packet;
(2) determining at a physical layer whether the integrity value is correct;
(3) if the integrity value is incorrect, then
(i) increasing an integrity error count;
(ii) comparing the integrity error count against an integrity error threshold;
(iii) if the integrity error count satisfies a condition relative to the integrity error threshold, then setting or maintaining the receive status of the wireless link at the receiving node as ‘bad’; and
(iv) if the integrity error count fails to satisfy the condition relative to the integrity error threshold, then maintaining the receive status of the wireless link at the receiving node as ‘good’; and
(4) if the integrity value is correct, then
(i) resetting the integrity error count;
(ii) increasing an integrity correct count;
(ii) comparing the integrity correct count against an integrity correct threshold;
(iv) if the integrity correct count satisfies a condition relative to the integrity correct threshold, then setting or maintaining the receive status of the wireless link at the receiving node as ‘good’; and
(v) if the integrity correct count fails to satisfy the condition relative to the integrity correct threshold, then maintaining the receive status of the wireless link at the receiving node as ‘bad’;
(d) inserting the receive status of the wireless link at the receiving node in a header of a second packet, and transmitting the second packet to the transmitting node, the receive status of the wireless link at the receiving node being used by the transmitting node as the transmit status of the wireless link at the transmitting node;
(e) repeating step (d) on a periodic basis; and
(f) extracting a receive status of the wireless link at the transmitting node from the first packet received from the transmitting node, and using the receive status of the wireless link at the transmitting node as the transmit status of the wireless link at the receiving node.
2. The method of claim 1 , wherein the method is performed by a data access card.
3. The method of claim 1 , wherein the transmitting node is configured not to send any data packets to the receiving node over the wireless link until the receive status of the wireless link at the receiving node is set to ‘good’.
4. The method of claim 1 , wherein the wireless link at the receiving node may have a receive status set as ‘bad’ and a transmitting status set as ‘good’.
5. The method of claim 1 , further comprising setting a status of the wireless link aggregation group as ‘bad’ when all of the multiple wireless links of the wireless link aggregation group are set to ‘bad’.
6. The method of claim 1 , further comprising setting a status of the wireless link aggregation group as ‘good’ when at least one of the multiple wireless links of the wireless link aggregation group is set to ‘good’.
7. The method of claim 1 , wherein the detecting the integrity value includes detecting at least one of traffic alignment or packet integrity.
8. The method of claim 1 , wherein the detecting the integrity value includes detecting a cyclic redundancy checksum (CRC).
9. A data access card configured to detect a transmit status and a receive status of a receiving node of a wireless link of multiple wireless links in a wireless link aggregation group, the data access card including circuitry configured to perform:
(a) detecting by a receiving node whether a first packet was received from a transmitting node over the wireless link, the wireless link at the receiving node having a transmit status and a receive status;
(b) if the first packet has not been received by the receiving node from the transmitting node over the wireless link, then
(1) computing a time interval since last receipt of any packet from the transmitting node over the wireless link;
(2) comparing the time interval against a time interval threshold; and
(3) if the time interval fails a condition relative to the time interval threshold, then setting the receive status of the wireless link at the receiving node to ‘bad’;
(c) if the first packet has been received by the receiving node from the transmitting node over the wireless link, then
(1) computing at a physical layer an integrity value of the packet;
(2) determining at a physical layer whether the integrity value is correct;
(3) if the integrity value is incorrect, then
(i) increasing an integrity error count;
(ii) comparing the integrity error count against an integrity error threshold;
(iii) if the integrity error count satisfies a condition relative to the integrity error threshold, then setting or maintaining the receive status of the wireless link at the receiving node as ‘bad’; and
(iv) if the integrity error count fails to satisfy the condition relative to the integrity error threshold, then maintaining the receive status of the wireless link at the receiving node as ‘good’; and
(4) if the integrity value is correct, then
(i) resetting the integrity error count;
(ii) increasing an integrity correct count;
(iii) comparing the integrity correct count against an integrity correct threshold;
(iv) if the integrity correct count satisfies a condition relative to the integrity correct threshold, then setting or maintaining the receive status of the wireless link at the receiving node as ‘good’; and
(v) if the integrity correct count fails to satisfy the condition relative to the integrity correct threshold, then maintaining the receive status of the wireless link at the receiving node as ‘bad’;
(d) inserting the receive status of the wireless link at the receiving node in a header of a second packet, and transmitting the second packet to the transmitting node, the receive status of the wireless link at the receiving node being used by the transmitting node as the transmit status of the wireless link at the transmitting node;
(e) repeating step (d) on a periodic basis; and
extracting a receive status of the wireless link at the transmitting node from the first packet received from the transmitting node, and using the receive status of the wireless link at the transmitting node as the transmit status of the wireless link at the receiving node.
10. The data access card of claim 9 , wherein the transmitting node is configured not to send any data packets to the receiving node over the wireless link until the receive status of the wireless link at the receiving node is set to ‘good’.
11. The data access card of claim 9 , wherein the wireless link at the receiving node may have a receive status set as ‘bad’ and a transmitting status set as ‘good’.
12. The data access card of claim 9 , wherein the data access card is further configured to set a status of the wireless link aggregation group as ‘bad’ when all of the multiple wireless links of the wireless link aggregation group are set to ‘bad’.
13. The data access card of claim 9 , wherein the data access card is further configured to set a status of the wireless link aggregation group as ‘good’ when at least one wireless link of the multiple wireless links of the wireless link aggregation group is set to ‘good’.
14. The data access card of claim 9 , wherein the data access card is further configured to detect at least one of traffic alignment or packet integrity.
15. The data access card of claim 9 , wherein the data access card is further configured to detect a cyclic redundancy checksum (CRC).