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-# Specification
-
-We use this document to detail the internal specification of Yamux.
-This is used both as a guide for implementing Yamux, but also for
-alternative interoperable libraries to be built.
-
-# Framing
-
-Yamux uses a streaming connection underneath, but imposes a message
-framing so that it can be shared between many logical streams. Each
-frame contains a header like:
-
-* Version (8 bits)
-* Type (8 bits)
-* Flags (16 bits)
-* StreamID (32 bits)
-* Length (32 bits)
-
-This means that each header has a 12 byte overhead.
-All fields are encoded in network order (big endian).
-Each field is described below:
-
-## Version Field
-
-The version field is used for future backward compatibility. At the
-current time, the field is always set to 0, to indicate the initial
-version.
-
-## Type Field
-
-The type field is used to switch the frame message type. The following
-message types are supported:
-
-* 0x0 Data - Used to transmit data. May transmit zero length payloads
- depending on the flags.
-
-* 0x1 Window Update - Used to updated the senders receive window size.
- This is used to implement per-session flow control.
-
-* 0x2 Ping - Used to measure RTT. It can also be used to heart-beat
- and do keep-alives over TCP.
-
-* 0x3 Go Away - Used to close a session.
-
-## Flag Field
-
-The flags field is used to provide additional information related
-to the message type. The following flags are supported:
-
-* 0x1 SYN - Signals the start of a new stream. May be sent with a data or
- window update message. Also sent with a ping to indicate outbound.
-
-* 0x2 ACK - Acknowledges the start of a new stream. May be sent with a data
- or window update message. Also sent with a ping to indicate response.
-
-* 0x4 FIN - Performs a half-close of a stream. May be sent with a data
- message or window update.
-
-* 0x8 RST - Reset a stream immediately. May be sent with a data or
- window update message.
-
-## StreamID Field
-
-The StreamID field is used to identify the logical stream the frame
-is addressing. The client side should use odd ID's, and the server even.
-This prevents any collisions. Additionally, the 0 ID is reserved to represent
-the session.
-
-Both Ping and Go Away messages should always use the 0 StreamID.
-
-## Length Field
-
-The meaning of the length field depends on the message type:
-
-* Data - provides the length of bytes following the header
-* Window update - provides a delta update to the window size
-* Ping - Contains an opaque value, echoed back
-* Go Away - Contains an error code
-
-# Message Flow
-
-There is no explicit connection setup, as Yamux relies on an underlying
-transport to be provided. However, there is a distinction between client
-and server side of the connection.
-
-## Opening a stream
-
-To open a stream, an initial data or window update frame is sent
-with a new StreamID. The SYN flag should be set to signal a new stream.
-
-The receiver must then reply with either a data or window update frame
-with the StreamID along with the ACK flag to accept the stream or with
-the RST flag to reject the stream.
-
-Because we are relying on the reliable stream underneath, a connection
-can begin sending data once the SYN flag is sent. The corresponding
-ACK does not need to be received. This is particularly well suited
-for an RPC system where a client wants to open a stream and immediately
-fire a request without waiting for the RTT of the ACK.
-
-This does introduce the possibility of a connection being rejected
-after data has been sent already. This is a slight semantic difference
-from TCP, where the conection cannot be refused after it is opened.
-Clients should be prepared to handle this by checking for an error
-that indicates a RST was received.
-
-## Closing a stream
-
-To close a stream, either side sends a data or window update frame
-along with the FIN flag. This does a half-close indicating the sender
-will send no further data.
-
-Once both sides have closed the connection, the stream is closed.
-
-Alternatively, if an error occurs, the RST flag can be used to
-hard close a stream immediately.
-
-## Flow Control
-
-When Yamux is initially starts each stream with a 256KB window size.
-There is no window size for the session.
-
-To prevent the streams from stalling, window update frames should be
-sent regularly. Yamux can be configured to provide a larger limit for
-windows sizes. Both sides assume the initial 256KB window, but can
-immediately send a window update as part of the SYN/ACK indicating a
-larger window.
-
-Both sides should track the number of bytes sent in Data frames
-only, as only they are tracked as part of the window size.
-
-## Session termination
-
-When a session is being terminated, the Go Away message should
-be sent. The Length should be set to one of the following to
-provide an error code:
-
-* 0x0 Normal termination
-* 0x1 Protocol error
-* 0x2 Internal error
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