svcadm(8)을 검색하려면 섹션에서 8 을 선택하고, 맨 페이지 이름에 svcadm을 입력하고 검색을 누른다.
cc_vegas(4)
The Vegas congestion control algorithm uses what the authors term
the actual and expected transmission rates to determine whether
there is congestion along the network path i.e. actual rate =
(total data sent in a RTT) / RTT expected rate = cwnd / RTTmin
diff = expected - actual where RTT is the measured instantaneous
round trip time and RTTmin is the smallest round trip time ob‐
served during the connection. The algorithm aims to keep diff
between two parameters alpha and beta, such that: alpha < diff <
beta If diff > beta, congestion is inferred and cwnd is decre‐
mented by one packet (or the maximum TCP segment size). If diff
< alpha, then cwnd is incremented by one packet. Alpha and beta
govern the amount of buffering along the path. The implementa‐
tion was done in a clean-room fashion, and is based on the paper
referenced in the section below. The time from the transmission
of a marked packet until the receipt of an acknowledgement for
that packet is measured once per RTT. This implementation does
not implement Brakmo's and Peterson's original duplicate ACK pol‐
icy since clock ticks in today's machines are not as coarse as
they were (i.e. 500ms) when Vegas was originally designed. Note
that modern TCP recovery processes such as fast retransmit and
SACK are enabled by default in the TCP stack. The algorithm ex‐
poses the following tunable variables in the branch of the MIB:
Query or set the Vegas alpha parameter as a number of buffers on
the path. When setting alpha, the value must satisfy: 0 < alpha
< beta. Default is 1. Query or set the Vegas beta parameter as
a number of buffers on the path. When setting beta, the value
must satisfy: 0 < alpha < beta. Default is 3. Development and
testing of this software were made possible in part by grants
from the FreeBSD Foundation and Cisco University Research Program
Fund at Community Foundation Silicon Valley. The congestion con‐
trol module first appeared in The module was first released in
2010 by David Hayes whilst working on the NewTCP research project
at Swinburne University of Technology's Centre for Advanced In‐
ternet Architectures, Melbourne, Australia. More details are
available at: http://caia.swin.edu.au/urp/newtcp/ The congestion
control module and this manual page were written by