SACK_GapBlockReport.seq - Any received DATA chunks with TSN greater than the Cumulative TSN Ack be reported in the Gap Ack Block fields
To check that any received DATA chunks with TSN greater than the
value in the Cumulative TSN Ack field SHOULD also be reported in
the Gap Ack Block fields.
./SACK_GapBlockReport.seq [-tooloption ...] -pkt ./SACK_GapBlockReport.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 data
in endpoint A such that DATA message with TSN greater than the
value in the Cumulative TSN Ack field are sent to endpoint B.
Endpoint A Endpoint B ULP
(ESTABLISHED) (ESTABLISHED)
DATA ---------------->
(TSN greater than the value in the Cumulative TSN Ack field)
<---------------- SACK (Gap Block Report)
TEST DESCRIPTION:
1. Send DATA message with TSN greater than the value in the
Cumulative TSN Ack field are sent to endpoint B.
2. Check A: SACK with Gap Ack Block is send to acknowledge
the reception of DATA chunk from endpoint B.
None
RFC 4960
6.2. Acknowledgement on Reception of DATA Chunks
Acknowledgements MUST be sent in SACK chunks unless shutdown was
requested by the ULP, in which case an endpoint MAY send an
acknowledgement in the SHUTDOWN chunk. A SACK chunk can acknowledge
the reception of multiple DATA chunks. See Section 3.3.4 for SACK
chunk format. In particular, the SCTP endpoint MUST fill in the
Cumulative TSN Ack field to indicate the latest sequential TSN (of a
valid DATA chunk) it has received. Any received DATA chunks with TSN
greater than the value in the Cumulative TSN Ack field are reported
in the Gap Ack Block fields. The SCTP endpoint MUST report as many
Gap Ack Blocks as can fit in a single SACK chunk limited by the
current path MTU.