NAME

  T5ShutdownGuardExpires.seq - Abort the association by sending an ABORT chunk if T5-shutdown-guard timer expires

PURPOSE

  To check that at the expiration of T5-shutdown-guard timer, the sender SHOULD
  abort the association by sending an ABORT chunk.

SYNOPSIS

  ./T5ShutdownGuardExpires.seq [-tooloption ...] -pkt ./T5ShutdownGuardExpires.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 no SHUTDOWN ACK is sent in response
  to SHUTDOWN.

TEST PROCEDURE

  Endpoint A                           Endpoint B                ULP
  (ESTABLISHED)                        (ESTABLISHED)

                                                   <-----    Terminate
                <-----------------      SHUTDOWN
                                           |
                                           | T2-Shutdown
                                           | Timer
                                           |
                <-----------------      SHUTDOWN

  DATA          ----------------->

                <-----------------      SACK

                <-----------------      SHUTDOWN
                                           |
                                           | T2-Shutdown
                                           | Timer
                                           |
                <-----------------      SHUTDOWN

  DATA          ----------------->

                <-----------------      SACK

                <-----------------      SHUTDOWN
                                           .
                                           . Retransmit x
                                           .  times
                <-----------------      ABORT

  TEST DESCRIPTION:

  1. Try to terminate an association between endpoint A and endpoint B by 
     sending SHUTDOWN message from endpoint B.Don't send the SHUTDOWN-ACK 
     from the endpoint A.
  2. Check A: SHUTDOWN message is transmitted again if T2-shutdown timer
     expires.
  3. Send DATA message from the endpoint A.
  4. SACK chunk and SHUTDOWN chunk is send immediately to the endpoint A.
  5. Check B: Repeat step 3~4 some times, at the expiration of T5-shutdown-guard, 
     timer, the sender SHOULD abort the association by sending an ABORT chunk.

NOTE

  None

REFERENCE

  RFC 4960

  9.2.  Shutdown of an Association

    The sender of the SHUTDOWN MAY also start an overall guard timer
    'T5-shutdown-guard' to bound the overall time for the shutdown
    sequence.  At the expiration of this timer, the sender SHOULD abort
    the association by sending an ABORT chunk.  If the 'T5-shutdown-
    guard' timer is used, it SHOULD be set to the recommended value of 5
    times 'RTO.Max'.

    If the receiver of the SHUTDOWN has no more outstanding DATA chunks,
    the SHUTDOWN receiver MUST send a SHUTDOWN ACK and start a T2-
    shutdown timer of its own, entering the SHUTDOWN-ACK-SENT state.  If
    the timer expires, the endpoint must resend the SHUTDOWN ACK.