Parallel redundancy protocol over wide area networks

Patent metadata

Field	Value
Publication number	US-10044644-B2
Application number	US-201715397184-A
Country	US
Kind code	B2
Filing date	Jan 3, 2017
Priority date	Dec 31, 2015
Publication date	Aug 7, 2018
Grant date	Aug 7, 2018

Abstract

A parallel redundancy protocol (PRP) frame is generated at a first electronic device for transmission to a second electronic device over a LAN and a WAN. The PRP frame includes a source MAC address field, packet data, and a redundancy control trailer (RCT). The RCT is compliant with IEC standard 62439-3 and includes a sequence number field, a LAN identifier field, and a frame size field. The source MAC address of the first electronic device and at least one of a sequence number, a LAN identifier and a frame size for the RCT fields of the PRP frame are encoded, and the encoded data is inserted in at least one of the RCT fields of the PRP frame in place of the sequence number, LAN identifier and/or frame size. The PRP frame is transmitted to the second electronic device with the encoded data in the RCT.

First claim

What is claimed is:

1. A method of implementing parallel redundancy, the method comprising:
generating a first parallel redundancy protocol (PRP) frame at a first electronic device for transmission to a second electronic device over a first local area network (LAN) and a wide area network (WAN), the first PRP frame comprising a source media access control (MAC) address field, packet data, and a redundancy control trailer (RCT), the RCT being compliant with International Electrotechnical Commission (IEC) standard 62439-3 and including a sequence number field, a LAN identifier field, and a frame size field;
encoding a source MAC address of the first electronic device and at least one of a sequence number, a LAN identifier and a frame size for the RCT fields of the first PRP frame into encoded data;
inserting the encoded data in at least one of the RCT fields of the first PRP frame in place of at least one of the sequence number, the LAN identifier and the frame size; and
transmitting the first PRP frame with the encoded data in the RCT to the second electronic device.

2. The method of claim 1 , wherein encoding the source MAC address of the first electronic device and at least one of the sequence number, the LAN identifier and the frame size into the encoded data comprises:
translating the source MAC address of the first electronic device from an M-byte initial MAC address value to an N-byte hashed MAC address value using a hashing function, wherein M and N are integers and M>N; and
XORing the N-byte hashed MAC address value and at least one of the sequence number, the LAN identifier and the frame size.

3. The method of claim 2 , wherein M=6, N=4 and the encoded data occupies all of the RCT fields of the first PRP frame in place of the sequence number, the LAN identifier and the frame size.

4. The method of claim 2 , further comprising:
modifying a length of the hash function based on a number of electronic devices included in the first LAN, so that N corresponds to the number of electronic devices included in the first LAN.

5. The method of claim 1 , wherein encoding the source MAC address of the first electronic device and at least one of the sequence number, the LAN identifier and the frame size into the encoded data comprises:
accessing a lookup table which associates source MAC addresses, sequence numbers, LAN identifiers and frame sizes to different encoded data values; and
selecting the encoded data value associated with the source MAC address of the first electronic device, and the sequence number, the LAN identifier and the frame size for the RCT fields of the first PRP frame.

6. The method of claim 1 , further comprising:
verifying that the second electronic device does not belong to the first LAN prior to inserting the encoded data in at least one of the RCT fields of the first PRP frame in place of at least one of the sequence number, the LAN identifier and the frame size.

7. The method of claim 6 , wherein verifying that the second electronic device does not belong to the first LAN comprises:
determining that a destination MAC address included in the first PRP frame identifies a local router associated with the first LAN.

8. The method of claim 1 , further comprising:
generating a second PRP frame at the first electronic device for transmission to the second electronic device over a second LAN different than the first LAN and a WAN, the second PRP frame comprising a source MAC address field, the same packet data as the first PRP frame, and an RCT which is compliant with IEC standard 62439-3 and includes a sequence number field, a LAN identifier field, and a frame size field;
encoding the source MAC address of the first electronic device and at least one of a sequence number, a LAN identifier and a frame size for the RCT fields of the second PRP frame into encoded data, wherein the LAN identifier for the first PRP packet identifies the first LAN and the LAN identifier for the second PRP packet identifies the second LAN;
inserting the encoded data for the second PRP frame in at least one of the RCT fields of the second PRP frame in place of at least one of the sequence number, the LAN identifier and the frame size for the second PRP frame; and
transmitting the second PRP frame with the encoded data in the RCT to the second electronic device.

9. The method of claim 1 , further comprising:
generating a second PRP frame at the first electronic device for transmission to a third electronic device that belongs to the first LAN, the second PRP frame comprising a source MAC address field and an RCT, the RCT being compliant with IEC standard 62439-3 and including a sequence number field, a LAN identifier field, and a frame size field;
inserting the source MAC address of the first electronic device in the source MAC address field of the second PRP frame;
inserting a sequence number, a LAN identifier and a frame size for the second PRP frame in the corresponding RCT fields of the second PRP frame, responsive to verifying that the third electronic device belongs to the first LAN; and
transmitting the second PRP frame with the sequence number, the LAN identifier and the frame size in the RCT of the second PRP frame to the third electronic device over a different LAN than the first PRP frame.

10. An electronic device in a power generation, transmission or distribution system, comprising:
a processing circuit operable to:
generate a first parallel redundancy protocol (PRP) frame for transmission to a remote device over a first local area network (LAN) and a wide area network (WAN), the first PRP frame comprising a source media access control (MAC) address field, packet data, and a redundancy control trailer (RCT), the RCT being compliant with International Electrotechnical Commission (IEC) standard 62439-3 and including a sequence number field, a LAN identifier field, and a frame size field;
encode a source MAC address of the electronic device and at least one of a sequence number, a LAN identifier and a frame size for the RCT fields of the first PRP frame into encoded data; and
insert the encoded data in at least one of the RCT fields of the first PRP frame in place of at least one of the sequence number, the LAN identifier and the frame size; and

transmit circuitry operable to transmit the first PRP frame with the encoded data in the RCT to the remote electronic device.

11. The electronic device of claim 10 , wherein the processing circuit is operable to translate the source MAC address of the electronic device from an M-byte initial MAC address value to an N-byte hashed MAC address value using a hashing function, wherein M and N are integers and M>N, and XOR the N-byte hashed MAC address value and at least one of the sequence number, the LAN identifier and the frame size.

12. The electronic device of claim 11 , wherein M=6, N=4 and the encoded data occupies all of the RCT fields of the first PRP frame in place of the sequence number, the LAN identifier and the frame size.

13. The electronic device of claim 11 , wherein the processing circuit is further operable to modify a length of the hash function based on a number of electronic devices included in the first LAN, so that N corresponds to the number of electronic devices included in the first LAN.

14. The electronic device of claim 10 , wherein the processing circuit is operable to access a lookup table which associates source MAC addresses, sequence numbers, LAN identifiers and frame sizes to different encoded data values, and select the encoded data value associated with the source MAC address of the electronic device, and the sequence number, the LAN identif

Assignees

• Abb Schweiz Ag

Inventors

• Ma Xiaoguang

Classifications

• H04L61/103

  across network layers, e.g. resolution of network layer into physical layer addresses or address resolution protocol [ARP] · CPC title

• H04L45/7453

  using hashing · CPC title

• H04L12/2801

  Broadband local area networks · CPC title

• H04L69/40 Primary

  for recovering from a failure of a protocol instance or entity, e.g. service redundancy protocols, protocol state redundancy or protocol service redirection (management of faults, events, alarms or notifications in data switching networks H04L41/06) · CPC title

• H04L69/03

  Protocol definition or specification  (protocol conformance testing H04L1/244) · CPC title