Hi, We have a websocket application which keeps writing data to the clients. We found that when tabs (not whole browser) of Firefox (ver. 22) is closed, the websocket connection is not closed. Anyway, reproducibility is very low. And the sendQ (netstat -an) keeps growing So, what we did is. we kept sending heart beat from client. If this heart beat timeout occurs, we are trying to close the connection as follows ByteBuffer bbuff = ByteBuffer.allocate(1); bbuff.put((byte) 0); messageInbound.getWsOutbound().close(0, bbuff); Is this correct approach to close the connection from server? Because, the connection is not closed at lower level (netstat -an). Anyway, writing data to it , is stopped and sendQ stops growing. # netstat -an | grep :8080 tcp 0 402376 172.22.59.176:8080 198.162.18.207:64805 ESTABLISHED Thanks and regards, Hidayath