fix(readme): update

readme.md

@@ -1625,6 +1625,34 @@ The `IProxyStats` interface provides the following methods:
 - `getConnectionsByRoute()`: Connection count per route
 - `getConnectionsByIP()`: Connection count per client IP
 
+Additional extended methods available:
+
+- `getThroughputRate()`: Bytes per second rate for the last minute
+- `getTopIPs(limit?: number)`: Get top IPs by connection count
+- `isIPBlocked(ip: string, maxConnectionsPerIP: number)`: Check if an IP has reached the connection limit
+
+### Extended Metrics Example
+
+```typescript
+const stats = proxy.getStats() as any; // Extended methods are available
+
+// Get throughput rate
+const rate = stats.getThroughputRate();
+console.log(`Incoming: ${rate.bytesInPerSec} bytes/sec`);
+console.log(`Outgoing: ${rate.bytesOutPerSec} bytes/sec`);
+
+// Get top 10 IPs by connection count
+const topIPs = stats.getTopIPs(10);
+topIPs.forEach(({ ip, connections }) => {
+  console.log(`${ip}: ${connections} connections`);
+});
+
+// Check if an IP should be rate limited
+if (stats.isIPBlocked('192.168.1.100', 100)) {
+  console.log('IP has too many connections');
+}
+```
+
 ### Monitoring Example
 
 ```typescript
@@ -2391,6 +2419,62 @@ createHttpToHttpsRedirect('old.example.com', 443)
 }
 ```
 
+## WebSocket Keep-Alive Configuration
+
+If your WebSocket connections are disconnecting every 30 seconds in SNI passthrough mode, here's how to configure keep-alive settings:
+
+### Extended Keep-Alive Treatment (Recommended)
+
+```typescript
+const proxy = new SmartProxy({
+  // Extend timeout for keep-alive connections
+  keepAliveTreatment: 'extended',
+  keepAliveInactivityMultiplier: 10, // 10x the base timeout
+  inactivityTimeout: 14400000, // 4 hours base (40 hours with multiplier)
+  
+  routes: [
+    {
+      name: 'websocket-passthrough',
+      match: { 
+        ports: 443, 
+        domains: ['ws.example.com', 'wss.example.com'] 
+      },
+      action: {
+        type: 'forward',
+        target: { host: 'backend', port: 443 },
+        tls: { mode: 'passthrough' }
+      }
+    }
+  ]
+});
+```
+
+### Immortal Connections (Never Timeout)
+
+```typescript
+const proxy = new SmartProxy({
+  // Never timeout keep-alive connections
+  keepAliveTreatment: 'immortal',
+  
+  routes: [
+    // ... same as above
+  ]
+});
+```
+
+### Understanding the Issue
+
+In SNI passthrough mode:
+1. **WebSocket Heartbeat**: The HTTP proxy's WebSocket handler sends ping frames every 30 seconds
+2. **SNI Passthrough**: In passthrough mode, traffic is encrypted end-to-end
+3. **Can't Inject Pings**: The proxy can't inject ping frames into encrypted traffic
+4. **Connection Terminated**: After 30 seconds, connection is marked inactive and closed
+
+The solution involves:
+- Longer grace periods for encrypted connections (5 minutes vs 30 seconds)
+- Relying on OS-level TCP keep-alive instead of application-level heartbeat
+- Different timeout strategies per route type
+
 ## Configuration Options
 
 ### SmartProxy (IRoutedSmartProxyOptions)
@@ -2401,6 +2485,7 @@ createHttpToHttpsRedirect('old.example.com', 443)
 - `httpProxyPort` (number, default 8443) - Port where HttpProxy listens for forwarded connections
 - Connection timeouts: `initialDataTimeout`, `socketTimeout`, `inactivityTimeout`, etc.
 - Socket opts: `noDelay`, `keepAlive`, `enableKeepAliveProbes`
+- Keep-alive configuration: `keepAliveTreatment` ('standard'|'extended'|'immortal'), `keepAliveInactivityMultiplier`
 - `certProvisionFunction` (callback) - Custom certificate provisioning
 
 #### SmartProxy Dynamic Port Management Methods