
i
i
“K16304” — 2012/11/19 — 9:15
i
i
i
i
i
i
4.2 Retransmission Policies
109
Timeout on dest B
2
-TSN X is rtxd
-TSNsY+2 & Y+3
incorrectly marked
for rtx !
TSN Y+2
B
1
A
1
A
2
B
2
Sender
A
Receiver
B
Receiver
B
SACK X
-
1 (X+1 to Y)
SACK X
-
1 (X+1 to Y+1)
TSN Y+3
TSN X (rtx
)
Incoming
SACKs
SACKs
that will
free up cwnd space
for destination B
1
SACKs
TSN Y+2
TSN Y+3
Spurious
rtxs
!!
LEGEND:
-
SACK X-1 (X+1 to Y) indicates a SACK with a cumack of X-1 carrying gap acks for TSNs from X+1
through Y. This SACK indicates that TSN X has not been received.
-
TSN Y+2 indicates a packet containing one data chunk with TSN Y+2. A data chunk is the smallest
indivisible unit of data in an SCTP packet.
Figure ...