NAME

  CwrWithBadChunkLength.seq - ECN-CWR chunk is received with invalid chunk length


PURPOSE

  To check that if ECN-CWR chunk is received with invalid chunk length, the
  endpoint should response with ABORT message.


SYNOPSIS

  ./CwrWithBadChunkLength.seq [-tooloption ...] -pkt ./CwrWithBadChunkLength.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 data 
  in endpoint A such that ECN-CWR chunk with invalid chunk length is 
  sent to endpoint A.


TEST PROCEDURE

  Endpoint A                           Endpoint B                ULP
  (ESTABLISHED)                        (ESTABLISHED)
  ECN_CWR       ----------------->
  (with invalid chunk length)
                <----------------      ABORT
  TEST DESCRIPTION:
  1. Send ECN_CWR chunk with invalid chunk length from endpoint A to 
     endpoint B.
  2. Check A: ABORT message will be sent to response ECN_CWR chunk from
     endpoint B.


NOTE

  None


REFERENCE

  RFC 4960
  Appendix A.  Explicit Congestion Notification
    ECN-Echo:
    [RFC3168] details a specific bit for a receiver to send back in its
    TCP acknowledgements to notify the sender of the Congestion
    Experienced (CE) bit having arrived from the network.  For SCTP, this
    same indication is made by including the ECNE chunk.  This chunk
    contains one data element, i.e., the lowest TSN associated with the
    IP datagram marked with the CE bit, and looks as follows:
         0                   1                   2                   3
         0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
        +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
        | Chunk Type=12 | Flags=00000000|    Chunk Length = 8           |
        +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
        |                      Lowest TSN Number                        |
        +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
        Note: The ECNE is considered a Control chunk.