Hello, > I see your point and what you have done in patches. > I'm only showing you that you may achieve almost the same effect > without any changes in kernel. I tested wstunnel. The performance comparison in my environment is as following. Round trip time of keyboard key down and up URBs at host. wstunnel: 4.4msec usbws(my patch): 2.7msec wstunnel passes TCP/IP stack twice so it's slower. I'd like to keep the usbws implementation because it's worth for performance. memory usage (VSZ/RSS) wstunnel usbws Server wstunnel 734K/20K usbipa 25K/2K usbwsa 25K/2K Client wstunnel 75K/17K usbipa 113K/3K Memo about wstunnel 1) Implementation node.js application 2) installation # yum install npm # npm install -g wstunnel 3) Usage for USB/IP app# insmod usbip-core.ko app# isnmod vhci-hcd.ko app# usbipa -t 3240 app$ wstunnel -s 8080 -t localhost:3240 dev# insmod usbip-core.ko dev# isnmod usbip-host.ko dev$ wstunnel -t 3240 ws://<app-side-addr>:8080 dev# usbip -t 3240 connect -r localhost -b <bus-id> usbip -<loop-back>- wstunnel ---<net>--- wstunnel -<loopback>- usbipa 3240 8080 3240 Some issues are found in interoperability (to use usbws with wstunnel). a) wstunnel needs Sec-WebSocket-Protocol header with value 'tunnel-protocol'. It means that the other end must be wstunnel too. b) wstunnel sends multiple packets into one frame. usbws must implement buffering. c) wstunnel sends WebSocket with FIN bit=1. Poco library translates it to OP_CLOSE and succeeding readFrame() doesn't work. I may fix later regarding b) if it's needed by other implementations. Sorry for my late response. I concentrated to other project. Thank you for your help, n.iwata // ��.n��������+%������w��{.n�����{���)��jg��������ݢj����G�������j:+v���w�m������w�������h�����٥