register_http_request_failed

Greetings,

For some reason I seem to be experiencing problems with jetpack and connecting to several of my website.

http://cambridge.wciworldwide.com/
http://nottingham.wciworldwide.com/
http://bicester.wciworldwide.com/
http://southampton.wciworldwide.com/
http://bedworth.wciworldwide.com/
http://loughborough.wciworldwide.com/

On each one of these sites it comes up with this message.

Jetpack could not contact WordPress.com: register_http_request_failed. This usually means something is incorrectly configured on your web host.
Operation timed out after 15 seconds with 0 bytes received

Please could you help.

Thanks

Jason