Datagram 1200

draft-ietf-quic-tls.md

@@ -515,28 +515,29 @@ older than 1.3 is negotiated.
 ## ClientHello Size {#clienthello-size}
 
 QUIC requires that the first Initial packet from a client be sent in a single
-UDP datagram.  This places constraints on the first ClientHello message.
+UDP datagram.  Though a packet larger than 1200 octets might be supported by the
+path, a client improves the likelihood that a packet is accepted if it ensures
+that the first ClientHello message it sends remains within this limit.
 
 QUIC packet and framing overheads add at least 36 octets of overheads to the
-ClientHello message.  That overhead increases if the client chooses connection
+ClientHello message.  That overhead increases if the client chooses a connection
 ID without zero length, nor does it include the token or a connection ID longer
-than octets that might be required if a server sends a Retry packet.
+than 8 octets that might be required if a server sends a Retry packet.
 
-With these overheads, a typical TLS ClientHello can fit into a 1200 octet packet
-with ample space remaining.  However, aside from the overheads added by QUIC,
-there are several variables that could cause this limit to be exceeded.  Large
-session tickets or HelloRetryRequest cookies, multiple or large key shares, and
-long lists of supported ciphers, signature algorithms, versions, QUIC transport
-parameters, and other negotiable parameters and extensions could cause this
-message to grow.
+A typical TLS ClientHello can easily fit into a 1200 octet packet.  However, in
+addition to the overheads added by QUIC, there are several variables that could
+cause this limit to be exceeded.  Large session tickets, multiple or large key
+shares, and long lists of supported ciphers, signature algorithms, versions,
+QUIC transport parameters, and other negotiable parameters and extensions could
+cause this message to grow.
 
 For servers, in addition to connection ID and tokens, the size of TLS session
-tickets and HelloRetryRequest cookie extensions can have an effect on a client's
-ability to connect.  Choosing a small value increases the probability that these
-values can be successfully used by a client.
+tickets can have an effect on a client's ability to connect.  Minimizing the
+size of these values increases the probability that they can be successfully
+used by a client.
 
-A client is not required to fit a ClientHello that is sent in response to
-HelloRetryRequest in a single UDP datagram.
+A client is not required to fit the ClientHello that it sends in response to a
+HelloRetryRequest message into a single UDP datagram.
 
 The TLS implementation does not need to ensure that the ClientHello is
 sufficiently large.  QUIC PADDING frames are added to increase the size of the