net/dccp/ccids/Kconfig

   1 menu "DCCP CCIDs Configuration (EXPERIMENTAL)"
   2         depends on EXPERIMENTAL
   3
   4 config IP_DCCP_CCID2_DEBUG
   5         bool "CCID-2 debugging messages"
   6         ---help---
   7           Enable CCID-2 specific debugging messages.
   8
   9           The debugging output can additionally be toggled by setting the
  10           ccid2_debug parameter to 0 or 1.
  11
  12           If in doubt, say N.
  13
  14 config IP_DCCP_CCID3
  15         bool "CCID-3 (TCP-Friendly) (EXPERIMENTAL)"
  16         def_bool y if (IP_DCCP = y || IP_DCCP = m)
  17         ---help---
  18           CCID-3 denotes TCP-Friendly Rate Control (TFRC), an equation-based
  19           rate-controlled congestion control mechanism.  TFRC is designed to
  20           be reasonably fair when competing for bandwidth with TCP-like flows,
  21           where a flow is "reasonably fair" if its sending rate is generally
  22           within a factor of two of the sending rate of a TCP flow under the
  23           same conditions.  However, TFRC has a much lower variation of
  24           throughput over time compared with TCP, which makes CCID-3 more
  25           suitable than CCID-2 for applications such streaming media where a
  26           relatively smooth sending rate is of importance.
  27
  28           CCID-3 is further described in RFC 4342,
  29           http://www.ietf.org/rfc/rfc4342.txt
  30
  31           The TFRC congestion control algorithms were initially described in
  32           RFC 5348.
  33
  34           This text was extracted from RFC 4340 (sec. 10.2),
  35           http://www.ietf.org/rfc/rfc4340.txt
  36
  37           If in doubt, say N.
  38
  39 config IP_DCCP_CCID3_DEBUG
  40         bool "CCID-3 debugging messages"
  41         depends on IP_DCCP_CCID3
  42         ---help---
  43           Enable CCID-3 specific debugging messages.
  44
  45           The debugging output can additionally be toggled by setting the
  46           ccid3_debug parameter to 0 or 1.
  47
  48           If in doubt, say N.
  49
  50 config IP_DCCP_CCID3_RTO
  51           int "Use higher bound for nofeedback timer"
  52           default 100
  53           depends on IP_DCCP_CCID3 && EXPERIMENTAL
  54           ---help---
  55             Use higher lower bound for nofeedback timer expiration.
  56
  57             The TFRC nofeedback timer normally expires after the maximum of 4
  58             RTTs and twice the current send interval (RFC 3448, 4.3). On LANs
  59             with a small RTT this can mean a high processing load and reduced
  60             performance, since then the nofeedback timer is triggered very
  61             frequently.
  62
  63             This option enables to set a higher lower bound for the nofeedback
  64             value. Values in units of milliseconds can be set here.
  65
  66             A value of 0 disables this feature by enforcing the value specified
  67             in RFC 3448. The following values have been suggested as bounds for
  68             experimental use:
  69                 * 16-20ms to match the typical multimedia inter-frame interval
  70                 * 100ms as a reasonable compromise [default]
  71                 * 1000ms corresponds to the lower TCP RTO bound (RFC 2988, 2.4)
  72
  73             The default of 100ms is a compromise between a large value for
  74             efficient DCCP implementations, and a small value to avoid disrupting
  75             the network in times of congestion.
  76
  77             The purpose of the nofeedback timer is to slow DCCP down when there
  78             is serious network congestion: experimenting with larger values should
  79             therefore not be performed on WANs.
  80
  81 config IP_DCCP_TFRC_LIB
  82         def_bool y if IP_DCCP_CCID3
  83
  84 config IP_DCCP_TFRC_DEBUG
  85         def_bool y if IP_DCCP_CCID3_DEBUG
  86 endmenu