)

    taskFaker.advanceUntil(520.ms)
    assertEvents(
      "plan 1 TCP connect failed",
    )

    taskFaker.advanceUntil(530.ms)
    assertEvents(
      "plan 2 TCP connect failed",
      "take plan 3",
      "plan 3 TCP connecting...",
    )

    taskFaker.advanceUntil(780.ms)
    assertEvents(
      "take plan 4",
      "plan 4 TCP connecting...",
    )

}
```

#### 4.5.2 Fallback TCP Provider
```java
package jcifs.internal.smb2.rdma.tcp;

public class TcpRdmaProvider implements RdmaProvider {
    @Override
    public boolean isAvailable() {
        return true;  // TCP is always available
    }
    
    @Override
    public Set<RdmaCapability> getSupportedCapabilities() {
        // TCP fallback only supports send/receive

After this, the client and the server have an **encrypted TCP connection**, this is what TLS provides. And then they can use that connection to start the actual **HTTP communication**.

And that's what **HTTPS** is, it's just plain **HTTP** inside a **secure TLS connection** instead of a pure (unencrypted) TCP connection.

/// tip

接著，用戶端與 TLS 終止代理會以該憑證為基礎，**協商後續如何加密**整段 **TCP 通訊**。至此完成 **TLS 握手**。

之後，用戶端與伺服器之間就有一條**已加密的 TCP 連線**，這就是 TLS 所提供的能力。接著他們可以在這條連線上開始實際的 **HTTP** 通訊。

這也就是 **HTTPS** 的本質：在**安全的 TLS 連線**內傳送一般的 **HTTP**，而非在純（未加密）的 TCP 連線上。

/// tip

請注意，加密發生在 **TCP 層**，不是在 HTTP 層。

///

### HTTPS 請求 { #https-request }

現在用戶端與伺服器（更精確地說，是瀏覽器與 TLS 終止代理）之間已有**加密的 TCP 連線**，他們可以開始進行 **HTTP** 通訊。

    @Test
    public void testRdmaProviderSelectionAlwaysReturnsProvider() {
        // This should always return at least the TCP fallback provider
        RdmaProvider provider = RdmaProviderFactory.selectBestProvider();
        assertNotNull(provider, "Should always select an RDMA provider (at minimum TCP fallback)");
        assertNotNull(provider.getProviderName(), "Provider name should not be null");

import okhttp3.internal.platform.Platform
import okhttp3.internal.tls.OkHostnameVerifier
import okhttp3.internal.toHostHeader

/**
 * A single attempt to connect to a remote server, including these steps:
 *
 *  * [TCP handshake][connectSocket]
 *  * Optional [CONNECT tunnels][connectTunnel]. When using an HTTP proxy to reach an HTTPS server
 *    we must send a `CONNECT` request, and handle authorization challenges from the proxy.

次に証明書を使用して、クライアントとTLS Termination Proxy は、 **TCP通信**の残りを**どのように暗号化するかを決定**します。これで**TLSハンドシェイク**の部分が完了します。

この後、クライアントとサーバーは**暗号化されたTCP接続**を持ちます。そして、その接続を使って実際の**HTTP通信**を開始することができます。

これが**HTTPS**であり、純粋な（暗号化されていない）TCP接続ではなく、**セキュアなTLS接続**の中に**HTTP**があるだけです。

/// tip | 豆知識

通信の暗号化は、HTTPレベルではなく、**TCPレベル**で行われることに注意してください。

///

### HTTPS リクエスト { #https-request }

        // Runtime exceptions and other errors are likely not recoverable
        return false;
    }

    /**
     * Check if error suggests fallback to TCP is needed
     *
     * @param error the error to check
     * @return true if TCP fallback is recommended
     */
    public boolean shouldFallbackToTcp(Exception error) {
        // Hardware errors suggest RDMA is not working

			Optional:    true,
			Type:        "duration",
		},
	}

	HelpMQTT = config.HelpKVS{
		config.HelpKV{
			Key:         target.MqttBroker,
			Description: "MQTT server endpoint e.g. `tcp://localhost:1883`",
			Type:        "uri",
			Sensitive:   true,
		},
		config.HelpKV{
			Key:         target.MqttTopic,
			Description: "name of the MQTT topic to publish",
			Type:        "string",
		},

- [ ] Implement RDMA transport layer
- [ ] Add RDMA buffer registration
- [ ] Create RDMA read/write operations
- [ ] Implement RDMA credits management
- [ ] Add fallback to TCP when RDMA unavailable

#### 5.3 Integration Points
- Create new transport type alongside TCP
- Modify negotiation to include RDMA contexts
- Update read/write operations for RDMA

---

### Phase 6: Witness Protocol