Abstract: A timing source is provided for sending timing information via a packet network. The source comprises a first clock for generating the timing information and a packet forming section for forming a sequence of packets. An output section in the form of a packet launch control section transmits the packets via the network as packet bursts, each of which comprises a plurality of packets with the intervals between consecutive packets of each burst being less than the intervals between consecutive packets. A time-stamping section inserts into each packet a transmission time derived from the timing information generated by the clock.

Abstract: A method of preparing packets for injection into a packet network at an ingress interface of the packet network, for transmission over the network. The method comprises, at the ingress interface, receiving at least two parallel, constant bit rate streams of data, and separately packetising the constant bit rate streams to generate respective packet flows for forwarding to a packet sender. The frequency of at least one of the packet flows with respect to another packet flow is set so as to reduce the degree of correlation between the packet flows, and the packet flows sent to the same or different egress interfaces over the packet network.