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.