+ * C) The receiver of a SHUTDOWN COMPLETE shall accept the packet
+ * if the Verification Tag field of the packet matches its own tag
+ * and the T bit is not set
+ * OR
+ * it is set to its peer's tag and the T bit is set in the Chunk
+ * Flags.
+ * Otherwise, the receiver MUST silently discard the packet
+ * and take no further action. An endpoint MUST ignore the
+ * SHUTDOWN COMPLETE if it is not in the SHUTDOWN-ACK-SENT state.