CZ--"HBONE (actual)"-->SZ
    SZ--Plain-->Server
```

### Pooling

User connections can be multiplexed over shared HBONE connections.
This is done through standard HTTP/2 pooling.
The pooling is keyed off the `{source identity, destination identity, destination ip}`.

### Headers

Ztunnel uses the following well-known headers in HBONE:

	ErrorLevel:    "error",
	CriticalLevel: "critical",
	OffLevel:      "off",
}

var stringToLevel = map[string]Level{
	"trace":    TraceLevel,
	"debug":    DebugLevel,
	"info":     InfoLevel,
	"warning":  WarningLevel,
	"warn":     WarningLevel,
	"error":    ErrorLevel,
	"critical": CriticalLevel,
	"off":      OffLevel,
}

var (
	loggerLevelString = ""
	reset             = false