OTN – Lesson 9 – Video 3 – OTU Layer Sink Direction Circuitry – Part 1

This post presents the 3rd of 11 Videos that covers training on Performance Monitoring at the OTU-Layer. This post focuses on the Sink-Direction OTU-Layer Atomic Functions.

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 out 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, as well as those portions that we did not.  

  • NOTE:  Back in Lesson 7, we discussed that part of the OTSiG/OTUk_A_Sk function that handled either OTL4.4 or OTL4.20 logical lane signals.  
  • Additionally, back in Lesson 6, we discussed that part of the OTSiG/OTUk_A_Sk function that handled OTL3.4 lane signal.  

I also show you the differences between the OTU3 version of 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 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.  

Continue reading “OTN – Lesson 9 – Video 3 – OTU Layer Sink Direction Circuitry – Part 1”

OTN – Lesson 9 – Video 2 – OTU Layer Source Direction – Part 2

This post presents the 2nd of 11 Videos that covers training on Performance Monitoring at the OTU-Layer. This post focuses on the Source-Direction OTU-Layer Atomic Functions.

OTN – Lesson 9 – Video 2 – OTU Layer Source Direction Circuitry/Functionality – Part 2

This blog post contains a video that discusses the OTU Layer Source Direction circuitry.  This video is the 2nd of 11 videos that focus on the OTU-Layer.

This particular video discusses the role/functionality of both the OTSiG/OTUk_A_So Atomic Function (aka OTL3.4 or OTL4.4 Source Terminal) and the OTSi/OTUk_A_So Atomic Function (for OTU1 and OTU2 applications).   

I will briefly describe the role of these atomic functions below.

Role of the OTSiG/OTUk_A_So Atomic Function

  • To insert the FAS/MFAS fields into the Outbound OTU3/OTU4 data-stream
  • Compute the FEC-field and insert it into the backend of each outbound OTU3 or OTU4 frame.
  • Scramble the outbound OTU3/OTU4 data-stream
  • Convert an OTU3 or OTU4 signal into an OTL3.4 or OTL4.4 set of signals, respectively.  
  • Forward this OTL3.4 or OTL4.4 set of signals to an Optical Module for further processing.  

Role of the OTSi/OTUk_A_So Atomic Function

  • To insert the FAS/MFAS fields  into the outbound OTU1/OTU2 data-stream
  • Computer the FEC-field and insert it into the backend of each outbound OTU1 or OTU2 frame.
  • Scramble the outbound OTU1/OTU2 data-stream.
  • Forward this scrambled (and FEC encoded) OTU1 or OTU2 data-stream to an Optical Module for further processing.  

Continue reading “OTN – Lesson 9 – Video 2 – OTU Layer Source Direction – Part 2”