System and method for resilient wireless packet communications
Rapid failure detection and recovery in wireless communication networks is needed in order to meet, among other things, carrier class Ethernet transport channel standards. Thus, resilient wireless packet communications is provided using a hardware-assisted rapid transport channel failure detection algorithm and a Gigabit Ethernet data access card with an engine configured accordingly. In networks with various topologies, this is provided in combination with their existing protocols, such as rapid spanning tree and link aggregation protocols, respectively.
1. A receiver system, comprising:
a port configured to receive data packets from a transmitter system over a wireless link, each of the data packets including a cyclic redundancy check (CRC) value;
registers storing a packet receive timeout value, a CRC error threshold value, and a CRC validation threshold value;
a first circuit configured to measure time while no data packets are being received, and configured to declare the wireless link bad when a time period based on the packet receive timeout value expires before any data packet is received;
a second circuit configured to evaluate the CRC value of each data packet received to evaluate validity of each data packet received;
a third circuit configured to count each data packet received and found to be invalid by the second circuit, and configured to declare the wireless link bad when a number of data packets received and found to be invalid exceeds a first threshold number based on the CRC error threshold value;
a fourth circuit configured to count each data packet received and found to be valid by the second circuit, and configured to declare the wireless link good upon satisfaction of a condition, the condition including that a number of data packets received and found to be valid exceeds a second threshold number based on the CRC validation threshold value; and
a fifth circuit configured to insert a receive status indicator in an outgoing data packet being sent to the transmitter system, the receive status indicator indicating whether the receiver system has declared the wireless link as good or bad, the transmitter system using the receive status indicator to identify its transmit status.
2. The receiver system of claim 1 , wherein the wireless link is a link of a link aggregation group.
3. The receiver system of claim 1 , wherein the transmitter system is configured to, when there are no data packets, send a keep-alive packet at a keep-alive insertion rate.
4. The receiver system of claim 1 , wherein the receiver system and the transmitter system are two nodes in a wireless network ring.
5. The receiver system of claim 1 , wherein the port configured to receive data packets includes a port configured to receive Ethernet data packets.
6. The receiver system of claim 1 , wherein the packet receive timeout value is the time period.
7. The receiver system of claim 1 , wherein the CRC error threshold value is the first threshold number.
8. The receiver system of claim 1 , wherein the CRC validation threshold value is the second threshold number.
9. A method, comprising:
storing a packet receive timeout value, a cyclic redundancy check (CRC) error threshold value, and a CRC validation threshold value;
measuring time while no data packets are being received from a transmitter system over a wireless link;
declaring the wireless link bad when a time period based on the packet receive timeout value expires before any data packet is received;
receiving data packets from the transmitter system over the wireless link, each of the data packets including a CRC value;
evaluating the CRC value of each data packet received to evaluate validity of each data packet received;
counting each data packet received and found to be invalid;
declaring the wireless link bad when a number of data packets received and found to be invalid exceeds a first threshold number based on the CRC error threshold value;
counting each data packet received and found to be valid;
declaring the wireless link good upon satisfaction of a condition, the condition including that a number of data packets received and found to be valid exceeds a second threshold number based on the CRC validation threshold value;
inserting a receive status indicator in an outgoing data packet being sent to the transmitter system, the receive status indicator indicating whether the receiver system has declared the wireless link as good or bad, the transmitter system using the receive status indicator to identify its transmit status; and
transmitting the outgoing data packet to the transmitter system.
10. The method of claim 9 , wherein the wireless link is a link of a link aggregation group.
11. The method of claim 9 , further comprising receiving a keep-alive packet at a keep-alive insertion rate from the transmitter system, when there are no data packets.
12. The method of claim 9 , wherein the transmitter system is a node in a wireless network ring.
13. The method of claim 9 , wherein receiving data packets includes receiving Ethernet data packets.
14. The method of claim 9 , wherein the packet receive timeout value is the time period.
15. The method of claim 9 , wherein the CRC error threshold value is the first threshold number.
16. The method of claim 9 , wherein the CRC validation threshold value is the second threshold number.