Method and system for link-based clock synchronization in asynchronous networks

A system for synchronizing a plurality of network devices in a network, the system comprising:

• a first data link coupling a first network device to an intermediary network device;
• a second data link coupling the intermediary network device to a second network device;
• at least one of the first data link and the second data link being an asynchronous data link;
• the first network device being configured to embed a first clock signal at a physical layer of the first data link;
• the intermediary network device being configured to:
• extract the first clock signal from the physical layer of the first data link;
• synchronize a first local clock based at least in part on the extracted first clock signal;
• embed a second clock signal at a physical layer of the second data link, the second clock signal representative of the first local clock;
• and
• adjust the second clock signal to a transmission rate of the second data link;
• and
• the second network device being configured to:
• extract the second clock signal from the physical layer of the second data link;
• synchronize a second local clock based at least in part on the extracted second clock signal.

A network device comprising:

• a first network interface operably connected to a first asynchronous data link and being configured to extract a first clock signal embedded at a physical layer of the first asynchronous data link;
• a phase-locked loop (PLL) operably connected to the first network interface and being configured to synchronize an output clock signal to the extracted clock signal;
• a second network interface operably connected to the PLL and to a second asynchronous data link and being configured to embed a second clock signal at a physical layer of the second asynchronous data link, the second clock signal based in part on the output clock signal;
• and
• means for adjusting the second clock signal to a transmission rate of the second asynchronous data link.

A method for synchronizing a plurality of network devices in a network, the method comprising:

• coupling an intermediary network device to a first data link;
• extracting, at the intermediary network device a first clock signal embedded at a physical layer of the first data link;
• synchronizing an output clock signal to the extracted first clock signal;
• coupling the intermediary network device to a second data link;
• embedding a second clock signal at a physical layer of the second data link, the second clock signal based at least in part on the output clock signal;
• and
• adjusting the second clock signal to a transmission rate of the second data link.