void addChannelListeners() {
        channelAtoB.addListener(this);
        channelAtoBControl.addListener(this);
        channelBtoA.addListener(this);
        channelBtoAControl.addListener(this);
    }
Adds listener to channel events like receiving data.
xmppserver/src/main/java/org/jivesoftware/openfire/mediaproxy/MediaProxySession.java