OTN – Lesson 9 – Video 3 – OTU Layer Sink Direction Circuitry/Functionality – Part 1
This blog post contains a video that begins our discussion of the Sink (Receive) Direction OTU-Layer Atomic Functions.
This Video starts with a brief re-cap of a portion of the OTSiG/OTUk_A_Sk Atomic Function (aka OTL4.4 Sink Terminal).
In this case, I specifically call out and identify portions of this Atomic Function that we discussed in Lessons 6 or 7 and those portions that we did not.
- In Lesson 7, we discussed that part of the OTSiG/OTUk_A_Sk function handled OTL4.4 or OTL4.20 logical lane signals.
- Lesson 6 also discussed part of the OTSiG/OTUk_A_Sk function that handled the OTL3.4 lane signal.
I also show you the differences between the OTU3 version of the OTSiG/OTUk_A_Sk function and that for OTU4.
Late in this Video, we start to discuss that portion of the OTSiG/OTUk_A_Sk function that handles the combined (composite) OTU3/OTU4 signal. This portion includes
- Discussing how the OTSiG/OTUk_A_Sk function declares and clears the dLOF defect by reviewing the Frame Alignment Block – dLOF/In-Frame State Machine Diagram, and
- Descrambling of the OTU3/OTU4 data stream.