Methods and systems for carrying synchronization over ethernet and optical transport network
The present disclosure relates to carrying synchronization through Ethernet, Optical Transport Network (OTN), and other asynchronous protocols. In one exemplary embodiment, timing markers or symbols are used in packets to enable a downstream device to recover timing based upon a time differential between markers or symbols. Advantageously, enabling Ethernet, OTN, etc. to carry synchronous information will de-risk switching from SONET/SDH to Ethernet and/or OTN for service providers. The present disclosure also includes frame decomposition scheme of the Ethernet stream. Ethernet packets are broken into fixed bandwidth and excess bandwidth. The fixed bandwidth is subdivided into fixed (negotiated) flits, with each flit corresponding to a specific user or combination of users like a private tunnel. This offers service providers a method to provide deterministic and more secure bandwidth over Ethernet to multiple clients.
1. A method for carrying synchronization, comprising:
inserting a first timing marker via a symbol in a line encoding scheme associated with a signal comprising Optical Transport Network (OTN) carrying an Ethernet stream, wherein both OTN and the Ethernet stream are asynchronous, wherein the first timing marker points to a second timing marker, wherein the first timing marker is configured to subdivide the Ethernet stream into fixed flits utilized for frame decomposition of the Ethernet stream for one or more clients, and wherein the fixed flits are collectively multiplexed to a higher rate in the Ethernet stream;
transmitting the signal with the first timing marker in the Ethernet stream within a payload of an OTN frame to a downstream node; and
establishing a timing reference based upon the first timing marker by extracting the first timing marker and the second timing marker from the payload.
2. The method of claim 1 , wherein the line encoding scheme comprises any of 8B/10B, 64B/66B, 64B/65B, and 512B/513B.
3. The method of claim 1 , further comprising:
inserting the second timing marker via the symbol in the line encoding scheme, wherein a timing difference between the first timing marker and the second timing marker defines the timing reference.
4. The method of claim 1 , wherein the method is performed by any of an Ethernet switch, a multi-service switch, a computer, a router, and an Optical Transport Network switch.
5. The method of claim 1 , and wherein the first timing marker is inserted with the highest priority through one of corrupting and retransmitting a current packet or inserting in a middle of a the current packet.
6. The method of claim 1 , wherein the first timing marker is an 8B/10B symbol.
7. The method of claim 1 , wherein the first timing marker is a 64B/66B symbol.
8. A network element, comprising:
a plurality of ports; and
circuitry communicatively coupled to one or more of the plurality of ports, wherein the circuitry is configured to insert timing markers pointing to subsequent timing markers in an Ethernet stream based upon a timing reference, wherein the timing markers are a symbol in a line encoding scheme associated with a signal comprising Optical Transport Network (OTN) carrying the Ethernet stream, wherein both OTN and the Ethernet stream are asynchronous, wherein the timing markers are configured to subdivide the Ethernet stream into fixed flits utilized for frame decomposition of the Ethernet stream for one or more clients, and wherein the fixed flits are collectively multiplexed to a higher rate in the Ethernet stream
wherein the timing markers are used by another network element configured to receive the OTN carrying the Ethernet stream to establish the timing reference based thereon.
9. The network element of claim 8 , wherein the line encoding scheme comprises any of 8B/10B, 64B/66B, 64B/65B, and 512B/513B.
10. The network element of claim 8 , wherein the timing markers are each inserted at a defined interval based on the timing reference.
11. The network element of claim 8 , wherein the network element comprises any of an Ethernet switch, a multi-service switch, a computer, a router, and an Optical Transport Network switch.
12. The network element of claim 8 , wherein the timing markers are inserted with the highest priority through one of corrupting and retransmitting a current packet or inserting in a middle of a the current packet.
13. The network element of claim 8 , wherein the timing marker is an 8B/10B symbol.
14. The network element of claim 8 , wherein the timing marker is a 64B/66B symbol.
15. A network, comprising:
a plurality of network elements interconnected therebetween and configured to interface data signals comprising Optical Transport Network (OTN) carrying Ethernet streams therebetween, wherein both OTN and the Ethernet streams are asynchronous, wherein the data signals comprise a line encoding scheme, wherein one or more of the plurality of network elements are configured to transmit synchronization over the data signals utilizing symbols in the line encoding scheme comprising timing markers pointing to subsequent timing markers in the Ethernet streams, wherein the timing markers are configured to subdivide the Ethernet streams into fixed flits utilized for frame decomposition of the Ethernet streams for one or more clients, and wherein the fixed flits are collectively multiplexed to a higher rate in the Ethernet streams;
wherein the timing markers are carried in OTN out-of-band.
16. The network of claim 15 , wherein the line encoding scheme comprises any of 8B/10B, 64B/66B, 64B/65B, and 512B/513B.
17. The network of claim 15 , wherein the timing marker is a 64B/66B symbol.