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“K16304” — 2012/11/19 — 9:15
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62
Fault Tolerance
cwnd exceeds ssthresh. Using the slow start cwnd growth model from Cardwell et
al. (2000), the last alternate path cwnd before exiting slow start is
cwnd = ssthresh = init_cwnd ·
1 +
1
b
r
ss
−1
(2.2)
where init_cwnd is the initial cwnd, b is the number of TPDUs per ack the receiver’s
delayed ack algorithm uses, and r
ss
is the number of alternate path round trips spent
in slow start. Since init_cwnd = 1, b = 2, and r
ss
≤ r, we can solve for r
ss
to arrive at
r
ss
= max
r, 1 + log
3
2
(ssthresh)
(2.3)
Using a component of the slow start data transfer model from Cardwell et al. (2000),
the number of TPDUs sent duri ...