BBC bitesize - Networks / Topologies. Read all pages then test yourself with the quiz at the end.
BBC bitesize - Wired / Wireless networks. Read all pages then test yourself with the quiz at the end. There is also a video on encryption
101Computing - Full of nice tasks that help with revision
Craig and Dave - Videos 23 through to 34 to cover the entire 1.3 subtopic
Exam questions and answers - The question pack is in the description but if you need help then the video explains all the questions and answers
End of topic test - A test that covers all of 1.3