| 摘要 |
The invention describes a method for transmitting data packets over a packet switching network with widely varying link speeds. The switches of the network maintain a common time reference (CTR). Each switch along a route from a source to a destination forwards data packets in periodic time frames (TFs) of a plurality of durations that are predefined using the CTR. The time frame duration can be longer than the time duration required for transmitting a data packet, in which case the exact position of a packet in the time frame is not predetermined. In accordance with the present invention, different time frame durations: TF1, TF2, and so on are used for forwarding over links with different capacities. This invention further describes a method for transmitting and forwarding data packets over a packet switching and shared media networks. The shared media network can be of various types, including but not limited to: IEEE P1394 and Ethernet for desktop computers and room area networks, cable modem head-end (e.g., DOCSIS, IEEE 802.14), wireless base-station (e.g., IEEE 802.11), and Storage Area Network (SAN) (e.g., FC-AL, SSA). The invention further describes a method for interfacing a packet-switched network with real-time streams from various sources, such as circuit-switched telephony network sources. A data packet that is packetized at the gateway is scheduled to be forwarded to the network in a predefined time that is responsive to the common time reference. The invention relates, in particular, to timely forwarding and delivery of data packet between voice over IP (VoIP) gateways. Consequently, the invention provides a routing service between any two VoIP gateways where the end-to-end performance parameters, such as loss, delay and jitter, have deterministic guarantees. Furthermore, the invention enables gateway functions with minimum delay. |
