diff --git a/internal/client/client.go b/internal/client/client.go
index 94d882b..3729588 100644
--- a/internal/client/client.go
+++ b/internal/client/client.go
@@ -247,6 +247,7 @@ func (c *Client) handleSOCKS5(conn net.Conn) {
 	conn.Write([]byte{5, 0, 0, 1, 0, 0, 0, 0, 0, 0})
 
 	done := make(chan struct{})
+	streamClosed := make(chan struct{})
 
 	go func() {
 		defer close(done)
@@ -257,11 +258,14 @@ func (c *Client) handleSOCKS5(conn net.Conn) {
 				c.mux.CloseStream(sid)
 				return
 			}
-			c.mux.SendData(sid, buf[:n])
+			if err := c.mux.SendData(sid, buf[:n]); err != nil {
+				return
+			}
 		}
 	}()
 
 	go func() {
+		defer close(streamClosed)
 		ticker := time.NewTicker(10 * time.Millisecond)
 		defer ticker.Stop()
 
@@ -272,7 +276,9 @@ func (c *Client) handleSOCKS5(conn net.Conn) {
 			case <-ticker.C:
 				data := c.mux.ReadStream(sid)
 				if len(data) > 0 {
-					conn.Write(data)
+					if _, err := conn.Write(data); err != nil {
+						return
+					}
 				}
 
 				if c.mux.StreamClosed(sid) {
@@ -282,5 +288,9 @@ func (c *Client) handleSOCKS5(conn net.Conn) {
 		}
 	}()
 
-	<-done
+	select {
+	case <-done:
+	case <-streamClosed:
+	}
+}
 }
diff --git a/internal/mux/mux.go b/internal/mux/mux.go
index 747c21a..9963567 100644
--- a/internal/mux/mux.go
+++ b/internal/mux/mux.go
@@ -18,21 +18,23 @@ type Stream struct {
 }
 
 type Multiplexer struct {
-	streams    map[uint16]*Stream
-	nextID     uint16
-	clientID   uint32
-	onSend     func([]byte) error
-	mu         sync.RWMutex
-	maxStreams int
+	streams       map[uint16]*Stream
+	nextID        uint16
+	clientID      uint32
+	onSend        func([]byte) error
+	mu            sync.RWMutex
+	maxStreams    int
+	maxBufferSize int
 }
 
 func New(clientID uint32, onSend func([]byte) error) *Multiplexer {
 	return &Multiplexer{
-		streams:    make(map[uint16]*Stream),
-		nextID:     1,
-		clientID:   clientID,
-		onSend:     onSend,
-		maxStreams: 10000,
+		streams:       make(map[uint16]*Stream),
+		nextID:        1,
+		clientID:      clientID,
+		onSend:        onSend,
+		maxStreams:    10000,
+		maxBufferSize: 1024 * 1024,
 	}
 }
 
@@ -40,15 +42,21 @@ func (m *Multiplexer) OpenStream() uint16 {
 	m.mu.Lock()
 	defer m.mu.Unlock()
 
-	sid := m.nextID
-	m.nextID++
-
-	m.streams[sid] = &Stream{
-		ID:     sid,
-		recvBuf: make([]byte, 0),
+	for {
+		sid := m.nextID
+		m.nextID++
+		if m.nextID == 0 {
+			m.nextID = 1
+		}
+		
+		if _, exists := m.streams[sid]; !exists {
+			m.streams[sid] = &Stream{
+				ID:      sid,
+				recvBuf: make([]byte, 0),
+			}
+			return sid
+		}
 	}
-
-	return sid
 }
 
 func (m *Multiplexer) SendData(sid uint16, data []byte) error {
@@ -135,10 +143,11 @@ func (m *Multiplexer) HandleFrame(frame []byte) {
 	data := frame[8 : 8+length]
 
 	m.mu.Lock()
+	defer m.mu.Unlock()
+	
 	stream, exists := m.streams[sid]
 	if !exists {
 		if len(m.streams) >= m.maxStreams {
-			m.mu.Unlock()
 			return
 		}
 		stream = &Stream{
@@ -152,8 +161,13 @@ func (m *Multiplexer) HandleFrame(frame []byte) {
 		stream.recvBuf = make([]byte, 0)
 		stream.closed = false
 	}
+	
+	if len(stream.recvBuf)+len(data) > m.maxBufferSize {
+		stream.closed = true
+		return
+	}
+	
 	stream.recvBuf = append(stream.recvBuf, data...)
-	m.mu.Unlock()
 }
 
 func (m *Multiplexer) ReadStream(sid uint16) []byte {
diff --git a/internal/server/server.go b/internal/server/server.go
index fc78124..0621be9 100644
--- a/internal/server/server.go
+++ b/internal/server/server.go
@@ -185,16 +185,13 @@ func (s *Server) run() error {
 			}
 
 			if s.mux.StreamClosed(sid) {
-				s.connMu.RLock()
+				s.connMu.Lock()
 				conn, exists := s.connections[sid]
-				s.connMu.RUnlock()
-				
 				if exists && conn != nil {
 					conn.Close()
-					s.connMu.Lock()
 					delete(s.connections, sid)
-					s.connMu.Unlock()
 				}
+				s.connMu.Unlock()
 			}
 		}
 	}
@@ -218,7 +215,7 @@ func (s *Server) handleConnect(sid uint16, req ConnectRequest) {
 	conn, err := net.DialTimeout("tcp", addr, 10*time.Second)
 	if err != nil {
 		log.Printf("Connect failed sid=%d: %v", sid, err)
-		s.mux.CloseStream(sid)
+		go s.mux.CloseStream(sid)
 		return
 	}
 
diff --git a/internal/telemost/peer.go b/internal/telemost/peer.go
index 9ee1920..d8a4cc3 100644
--- a/internal/telemost/peer.go
+++ b/internal/telemost/peer.go
@@ -424,15 +424,17 @@ func (p *Peer) sendLeave() {
 	p.wsMu.Lock()
 	defer p.wsMu.Unlock()
 	
-	if p.ws != nil {
-		leave := map[string]interface{}{
-			"uid":   uuid.New().String(),
-			"leave": map[string]interface{}{},
-		}
-		if err := p.ws.WriteJSON(leave); err == nil {
-			log.Println("Sent leave message to server")
-			time.Sleep(200 * time.Millisecond)
-		}
+	if p.ws == nil {
+		return
+	}
+	
+	leave := map[string]interface{}{
+		"uid":   uuid.New().String(),
+		"leave": map[string]interface{}{},
+	}
+	if err := p.ws.WriteJSON(leave); err == nil {
+		log.Println("Sent leave message to server")
+		time.Sleep(200 * time.Millisecond)
 	}
 }