Inserting ancillary content between first content and second content to be streamed over a network in accordance with a playlist

Inserting ancillary content between first content and second content to be streamed over a network in accordance with a playlist involves streaming the first content from a first location on the network, the location being defined in the playlist. Information indicating ancillary information (such as information relating to the network connection i.e. the stable bit rate, DRM information i.e. the decryption key, and the status of the client) relating to the streaming of the first content is stored 630. Ancillary content from a second, different, location on the network is streamed, the location being defined in the playlist. The location of the second content from the playlist is determined. When the location of the second content is the first location 635, streaming the second content using the stored ancillary information and when the location of the second content is different to the first location, deleting 640 the stored anciliary information. The invention may be used in Video over IP (VoIP) applications and may relate to the usage of resources relating to insertion of advertisements.