NAME

  HB_RecvInShutAckSend.seq - HEARTBEAT chunk is received in SHUTDOWN-ACK-SENT State


PURPOSE

  To check that if HEARTBEAT chunk is received in SHUTDOWN-ACK-SENT
  State, the endpoint should responds it by HEARTBEAT-ACK with
  the information carried in the Heartbeat message.


SYNOPSIS

  ./HB_RecvInShutAckSend.seq [-tooloption ...] -pkt ./HB_RespondWithAck.def
    -tooloption : v6eval tool option
  See Also: ../common/STD_PKT_COMMON.def
            ../common/SCTP_COMMON.def


PRE-TEST CONDITION

  Association is established between endpoint A and B. Arrange the data
  in endpoint A such that HEARTBEAT message is sent to endpoint B when
  endpoint B is in SHUTDOWN-ACK-SENT State.


TEST PROCEDURE

  Endpoint A                           Endpoint B                ULP
  (SHUTDOWN-SENT)                      (SHUTDOWN-ACK-SENT)
  HEARTBEAT        ----------------->
                   <-----------------    HEARTBEAT-ACK
                                         (Information copied from the
                                         HEARTBEAT message)
  TEST DESCRIPTION:
  1. Send HEARTBEAT message from endpoint A to B when endpoint B is in
     SHUTDOWN-ACK-SENT State.
     Record the message sequence using an emulator. 
  2. Check A: HEARTBEAT-ACK message will be sent in response to HEARTBEAT 
     message.
  3. Check B: Information carried in the HEARTBEAT message is carried 
     back into the HEARTBEAT-ACK message.
  4. Check C: After expiry of T2-shutdown timer SHUTDOWN-ACK message is 
     transmitted again.


NOTE

  None


REFERENCE

  RFC 4960
  8.3.  Path Heartbeat
    By default, an SCTP endpoint SHOULD monitor the reachability of the
    idle destination transport address(es) of its peer by sending a
    HEARTBEAT chunk periodically to the destination transport
    address(es).  HEARTBEAT sending MAY begin upon reaching the
    ESTABLISHED state and is discontinued after sending either SHUTDOWN
    or SHUTDOWN-ACK.  A receiver of a HEARTBEAT MUST respond to a
    HEARTBEAT with a HEARTBEAT-ACK after entering the COOKIE-ECHOED state
    (INIT sender) or the ESTABLISHED state (INIT receiver), up until
    reaching the SHUTDOWN-SENT state (SHUTDOWN sender) or the SHUTDOWN-
    ACK-SENT state (SHUTDOWN receiver).