Update Interface-Link-bring-up-sequence.md (#3)

Added breakout handling section.

doc/sfp-cmis/Interface-Link-bring-up-sequence.md

@@ -2,7 +2,7 @@
 Deterministic Approach for Interface Link bring-up sequence
 
 # High Level Design Document
-#### Rev 0.3
+#### Rev 0.7
 
 # Table of Contents
   * [List of Tables](#list-of-tables)
@@ -30,6 +30,7 @@ Deterministic Approach for Interface Link bring-up sequence
 | 0.4 | 01/26/2022  | Shyam Kumar,  Jaganathan Anbalagan | Addressed further review-comments 
 | 0.5 | 01/28/2022  | Shyam Kumar,  Jaganathan Anbalagan | Addressed further review-comments
 | 0.6 | 02/02/2022  | Shyam Kumar                        | Added feature-enablement workflow 
+| 0.7 | 02/02/2022  | Jaganathan Anbalagan               | Added Breakout Handling 
 
 
 # About this Manual
@@ -130,6 +131,11 @@ Work flows are designed considering SONiC NOS operating in sync mode.
 
 In case SONiC NOS operates in async mode, then expected behavior is - the return status of the set ADMIN_STATE attribute update in ASIC-DB (syncd/GBsyncd) will be treated to set the host_tx_ready in Orchagent.
 
+# Breakout Handling
+  - The new 'host_tx_ready' field of Port table in state-DB is created for every interface <regular/breakout interface>.
+  - Xcvrd processes the 'host_tx_ready' change event and is responsible to disable Tx/laser for all optical lanes or respective optical lane that belongs to the interface in case of breakout.
+  - Currently the logical mapping between the interface and optical lane is not present in xcvrd. Creating this logical mapping in xcvrd will address breakout interface handling.
+
 # Proposed Work-Flows
 
 Please refer to the  flow/sequence diagrams which covers the following required use-cases