menu "DCCP CCIDs Configuration (EXPERIMENTAL)"
- depends on IP_DCCP && EXPERIMENTAL
+ depends on EXPERIMENTAL
config IP_DCCP_CCID2
tristate "CCID2 (TCP-Like) (EXPERIMENTAL)"
- depends on IP_DCCP
def_tristate IP_DCCP
select IP_DCCP_ACKVEC
---help---
to the user. For example, a hypothetical application that
transferred files over DCCP, using application-level retransmissions
for lost packets, would prefer CCID 2 to CCID 3. On-line games may
- also prefer CCID 2.
+ also prefer CCID 2. See RFC 4341 for further details.
- CCID 2 is further described in:
- http://www.icir.org/kohler/dccp/draft-ietf-dccp-ccid2-10.txt
-
- This text was extracted from:
- http://www.icir.org/kohler/dccp/draft-ietf-dccp-spec-13.txt
-
- If in doubt, say M.
+ CCID2 is the default CCID used by DCCP.
config IP_DCCP_CCID2_DEBUG
- bool "CCID2 debug"
+ bool "CCID2 debugging messages"
depends on IP_DCCP_CCID2
---help---
- Enable CCID2 debug messages.
+ Enable CCID2-specific debugging messages.
+
+ When compiling CCID2 as a module, this debugging output can
+ additionally be toggled by setting the ccid2_debug module
+ parameter to 0 or 1.
If in doubt, say N.
config IP_DCCP_CCID3
tristate "CCID3 (TCP-Friendly) (EXPERIMENTAL)"
- depends on IP_DCCP
def_tristate IP_DCCP
+ select IP_DCCP_TFRC_LIB
---help---
CCID 3 denotes TCP-Friendly Rate Control (TFRC), an equation-based
rate-controlled congestion control mechanism. TFRC is designed to
suitable than CCID 2 for applications such streaming media where a
relatively smooth sending rate is of importance.
- CCID 3 is further described in:
-
- http://www.icir.org/kohler/dccp/draft-ietf-dccp-ccid3-11.txt.
+ 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 3448.
- This text was extracted from:
- http://www.icir.org/kohler/dccp/draft-ietf-dccp-spec-13.txt
+ This text was extracted from RFC 4340 (sec. 10.2),
+ http://www.ietf.org/rfc/rfc4340.txt
+ To compile this CCID as a module, choose M here: the module will be
+ called dccp_ccid3.
+
If in doubt, say M.
+config IP_DCCP_CCID3_DEBUG
+ bool "CCID3 debugging messages"
+ depends on IP_DCCP_CCID3
+ ---help---
+ Enable CCID3-specific debugging messages.
+
+ When compiling CCID3 as a module, this debugging output can
+ additionally be toggled by setting the ccid3_debug module
+ 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
- depends on IP_DCCP_CCID3
- def_tristate IP_DCCP_CCID3
+ tristate
+ default n
+
+config IP_DCCP_TFRC_DEBUG
+ bool
+ depends on IP_DCCP_TFRC_LIB
+ default y if IP_DCCP_CCID3_DEBUG
endmenu