remove negotiated spin

draft-ietf-quic-spin-exp.md

@@ -305,57 +305,3 @@ and Innovation under contract no. 15.0268. This support does not imply
 endorsement.
 
 --- back
-
-# Negotiating Spin Bit Usage
-
-This document describes the spin bit as a standard feature of the QUIC protocol.
-Alternately, the use or non-use of the spin bit could be negotiated using QUIC's
-version negotiation system. This section describes one method by which a version
-negotiated spin bit could work.
-
-We begin by assigning two version numbers to a given version of QUIC, which we
-will call version Vs and version Vt. Both headers use the same definition for
-the short header, as in {{header}}. Version Vs enables the spin bit, and version
-Vt disables it. For example, keeping with the version numbering scheme in
-Section 15 of {{QUIC-TRANSPORT}}, Vs could be 0x00000001, and Vt 0x00008001.
-
-A client proposing to use the spin bit for a connection sets version Vs in its
-Initial packet. If the server wants to support the spin bit for the connection,
-the handshake continues; otherwise, it sends a Version Negotiation packet
-proposing version Vt, and the Client restarts the handshake using version Vt,
-per Section 6 of {{QUIC-TRANSPORT}}.
-
-A client not wishing to use the spin bit sets version Vt in its Initial packet.
-To maintain the client's ability to choose whether to use the spin bit or not,
-the server MUST NOT reject an attempt to use version Vt with a proposal to use
-version Vs.
-
-Once version Vs is negotiated, client and server MUST enable the spin bit for
-the duration of the connectioon, by setting bit 0x04 in the first octet of each
-packet carrying a short header according to {{spinbit}}.
-
-Once version Vt is negotiated, client and server MUST disable the spin bit for
-the duration of the connection, by setting bit 0x04 in the first octet of each
-packet carrying a short header according to {{nospin}}.
-
-Negotiating the spin bit has a few properties that differ from the discretionary
-usage of the spin bit described in the main body of this document:
-
-- It provides a method to exercise version negotiation beyond the version
-  greasing mechanism described in section 15 of {{QUIC-TRANSPORT}}. This
-  additional exercise has the benefit of actually changing the protocol's
-  behavior in a way each endpoint can detect based on the negotiation of the
-  version, and may defend against ossification of the version negotiation
-  mechanism caused both by on-path interference as well as lazy implementations
-  better than greasing alone.
-
-- It provides a method by which on-path devices that observe the handshake can
-  explicitly classify a connection as spinning or not.
-
-## The Spin Bit in Spinless QUIC {#nospin}
-
-When version Vt is negotiated, both client and server randomly select a "pin
-value", 0 or 1, for each connection ID they will send packets with, and send
-this value as bit 0x04 in the first octet of each packet with a short header
-carrying the corresponding connection ID. This causes the spin bit to converge
-to a static state per connection ID.