On 9/20/07, Tommi Saviranta <wnd@xxxxxx> wrote: > Adds Kconfig-entries, modified Makefile, and adds DCCP_CCID enum for for > CCID 4. Kconfig-entries are derived from CCID 3, and are probably > invalid. > > > Signed-off-by: Tommi Saviranta <wnd@xxxxxx> > > +config IP_DCCP_CCID4 > + tristate "CCID4 (TCP-Friendly, Small Packet Variant) (EXPERIMENTAL)" But it doesn't depend on EXPERIMENTAL... This should be fixed. > + depends on IP_DCCP > + def_tristate IP_DCCP > + ---help--- > + CCID 4 denotes the Small-Packet variant of TCP-Friendly Rate Control > + (TFRC-SP), an equation-based rate-controlled congestion control > + mechanism. TFRC-SP 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-SP has a much lower variation of throughput over time compared > + with TCP, which makes CCID 4 more suitable than CCID 2 for > + applications such streaming media where a relatively smooth sending > + rate is of importance. > + > + CCID 4 is further described in RFC xxxx, > + http://www.ietf.org/rfc/rfcXXXX.txt > + This part should say that is an Internet Draft and give the URL for that. When it becomes a RFC a patch can then give the RFC number. > +config IP_DCCP_CCID4_RTO > + int "Use higher bound for nofeedback timer" > + default 100 > + depends on IP_DCCP_CCID4 && EXPERIMENTAL This EXPERIMENTAL can be removed with the changes to add to IP_DCCP_CCID4 as above > + ---help--- > + FIXME > + Use higher lower bound for nofeedback timer expiration. > + > + The TFRC-SP 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) > + But Linux actually uses 250 ms for TCP here, not 1000 ms. You might want to add that. -- Web1: http://wand.net.nz/~iam4/ Web2: http://www.jandi.co.nz Blog: http://iansblog.jandi.co.nz - To unsubscribe from this list: send the line "unsubscribe dccp" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
