# Hot Swap changes

Previously, Hot Swap was implemented as a Natural Access service (the HSI service). This interface is now implemented as an NMS OAM extended management component (EMC). The following list details changes to the API made as a result of the NMS OAM implementation. For further information, refer to the NMS OAM Service Developer's Reference Manual.

- The HSI service is deprecated and is not compatible with NMS OAM.

- The information formerly returned by HSI functions hsiGetBoardInfo and hsiGetLogicalBoardInfo is now available using other means, as follows:

  Information | New source
  --- | ---
  Board information | oamBoardGet XXX and oamBoardLookupBy XXX functions
  Hot Swap state | Hot Swap EMC Board.name.State keyword

- Hot Swap events are now passed to applications using the same event handling mechanism used for NMS OAM events. Hot Swap events and errors have not changed, except for their prefixes: Hot Swap events have the prefix HSWEVN_ and Hot Swap error codes have the prefix HSWERR_. They are specified in hswdef.h.

- A new state was added to the state machine: Unsupported. If a board does not support Hot Swap, it is permanently in this state.

- Hot Swap state names have changed, to be closer to their SNMP equivalents:

  Old state name | New state name
  --- | ---
  NOT PRESENT | Extracted
  OFFLINE | OffLine
  PREPARATION | OnLinePending
  PREPARATION FAILED | Failed
  RUNNING | OnLine
  DOWNING | OffLinePending
  (none) | Unsupported

- The Hot Swap Developer's Manual is now obsolete. For Hot Swap runtime information, refer to the Hot Swap topics in the manual you are currently reading. For Hot Swap developer information, refer to the NMS OAM Service Developer's Reference Manual.