T2ShutdownRetrans1.seq - SHUTDOWN message is transmitted again if T2-shutdown timer expires
To check that if T1-shutdown timer expires then the endpoint MUST retransmit SHUTDOWN and restart the T1-shutdown timer.
./T2ShutdownRetrans1.seq [-tooloption ...] -pkt ./T2ShutdownRetrans1.def -tooloption : v6eval tool option See Also: ../common/STD_PKT_COMMON.def ../common/SCTP_COMMON.def
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.
Endpoint A Endpoint B ULP (ESTABLISHED) (ESTABLISHED)
<----- Terminate <---------------- SHUTDOWN | | T2-Shutdown | Timer | <---------------- SHUTDOWN
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 or any DATAGRAM from the endpoint A. 2. Check A: After expiry of T2-Shutdown timer, SHUTDOWN message is sent again.
None
RFC 4960
9.2. Shutdown of an Association
Once all its outstanding data has been acknowledged, the endpoint shall send a SHUTDOWN chunk to its peer including in the Cumulative TSN Ack field the last sequential TSN it has received from the peer. It shall then start the T2-shutdown timer and enter the SHUTDOWN-SENT state. If the timer expires, the endpoint must resend the SHUTDOWN with the updated last sequential TSN received from its peer.
The rules in Section 6.3 MUST be followed to determine the proper timer value for T2-shutdown. To indicate any gaps in TSN, the endpoint may also bundle a SACK with the SHUTDOWN chunk in the same SCTP packet.
An endpoint should limit the number of retransmissions of the SHUTDOWN chunk to the protocol parameter 'Association.Max.Retrans'. If this threshold is exceeded, the endpoint should destroy the TCB and MUST report the peer endpoint unreachable to the upper layer (and thus the association enters the CLOSED state). The reception of any packet from its peer (i.e., as the peer sends all of its queued DATA chunks) should clear the endpoint's retransmission count and restart the T2-shutdown timer, giving its peer ample opportunity to transmit all of its queued DATA chunks that have not yet been sent.