> -----Original Message----- > From: Eric Dumazet <[email protected]> > Sent: Tuesday, January 20, 2026 10:54 AM > To: Chia-Yu Chang (Nokia) <[email protected]> > Cc: [email protected]; [email protected]; [email protected]; > [email protected]; [email protected]; [email protected]; [email protected]; > [email protected]; [email protected]; [email protected]; > [email protected]; [email protected]; [email protected]; > [email protected]; [email protected]; [email protected]; > [email protected]; [email protected]; [email protected]; > [email protected]; [email protected]; [email protected]; > [email protected]; [email protected]; Koen De Schepper (Nokia) > <[email protected]>; [email protected]; > [email protected]; [email protected]; cheshire > <[email protected]>; [email protected]; [email protected]; Vidhi Goel > <[email protected]>; Olivier Tilmans (Nokia) <[email protected]> > Subject: Re: [PATCH v9 net-next 04/15] tcp: ECT_1_NEGOTIATION and > NEEDS_ACCECN identifiers > > > CAUTION: This is an external email. Please be very careful when clicking > links or opening attachments. See the URL nok.it/ext for additional > information. > > > > On Mon, Jan 19, 2026 at 7:59 PM <[email protected]> wrote: > > > > From: Chia-Yu Chang <[email protected]> > > > > Two CA module flags are added in this patch related to AccECN negotiation. > > First, a new CA module flag (TCP_CONG_NEEDS_ACCECN) defines that the > > CA expects to negotiate AccECN functionality using the ECE, CWR and AE > > flags in the TCP header. > > > > Second, during ECN negotiation, ECT(0) in the IP header is used. This > > patch enables CA to control whether ECT(0) or ECT(1) should be used on > > a per-segment basis. A new flag (TCP_CONG_ECT_1_NEGOTIATION) defines > > the expected ECT value in the IP header by the CA when not-yet initialized > > for the connection. > > > > The detailed AccECN negotiaotn during the 3WHS can be found in the AccECN > > spec: > > https://tools.ietf.org/id/draft-ietf-tcpm-accurate-ecn-28.txt > > While for some reason linux uses icsk_ca_ops, I think the terminology is > about "CC : Congestion Control" > > Not sure what CA means... > > Reviewed-by: Eric Dumazet <[email protected]>
Thanks for feedback, I will change into CC in the next version. Chia-Yu
