menu "DCCP CCIDs Configuration (EXPERIMENTAL)" depends on EXPERIMENTAL config IP_DCCP_CCID2_DEBUG bool "CCID-2 debugging messages" ---help--- Enable CCID-2 specific debugging messages. The debugging output can additionally be toggled by setting the ccid2_debug parameter to 0 or 1. If in doubt, say N. config IP_DCCP_CCID3 bool "CCID-3 (TCP-Friendly) (EXPERIMENTAL)" def_bool y if (IP_DCCP = y || IP_DCCP = m) ---help--- CCID-3 denotes TCP-Friendly Rate Control (TFRC), an equation-based rate-controlled congestion control mechanism. TFRC is designed to be reasonably fair when competing for bandwidth with TCP-like flows, where a flow is "reasonably fair" if its sending rate is generally within a factor of two of the sending rate of a TCP flow under the same conditions. However, TFRC has a much lower variation of throughput over time compared with TCP, which makes CCID-3 more suitable than CCID-2 for applications such streaming media where a relatively smooth sending rate is of importance. CCID-3 is further described in RFC 4342, http://www.ietf.org/rfc/rfc4342.txt The TFRC congestion control algorithms were initially described in RFC 5448. This text was extracted from RFC 4340 (sec. 10.2), http://www.ietf.org/rfc/rfc4340.txt If in doubt, say N. config IP_DCCP_CCID3_DEBUG bool "CCID-3 debugging messages" depends on IP_DCCP_CCID3 ---help--- Enable CCID-3 specific debugging messages. The debugging output can additionally be toggled by setting the ccid3_debug parameter to 0 or 1. If in doubt, say N. config IP_DCCP_CCID3_RTO int "Use higher bound for nofeedback timer" default 100 depends on IP_DCCP_CCID3 && EXPERIMENTAL ---help--- Use higher lower bound for nofeedback timer expiration. The TFRC nofeedback timer normally expires after the maximum of 4 RTTs and twice the current send interval (RFC 3448, 4.3). On LANs with a small RTT this can mean a high processing load and reduced performance, since then the nofeedback timer is triggered very frequently. This option enables to set a higher lower bound for the nofeedback value. Values in units of milliseconds can be set here. A value of 0 disables this feature by enforcing the value specified in RFC 3448. The following values have been suggested as bounds for experimental use: * 16-20ms to match the typical multimedia inter-frame interval * 100ms as a reasonable compromise [default] * 1000ms corresponds to the lower TCP RTO bound (RFC 2988, 2.4) The default of 100ms is a compromise between a large value for efficient DCCP implementations, and a small value to avoid disrupting the network in times of congestion. The purpose of the nofeedback timer is to slow DCCP down when there is serious network congestion: experimenting with larger values should therefore not be performed on WANs. config IP_DCCP_TFRC_LIB def_bool y if IP_DCCP_CCID3 config IP_DCCP_TFRC_DEBUG def_bool y if IP_DCCP_CCID3_DEBUG endmenu