Electrical computers and digital processing systems: multicomput – Computer-to-computer data routing – Alternate path routing
Patent
1997-06-09
1999-08-03
Luu, Le Hien
Electrical computers and digital processing systems: multicomput
Computer-to-computer data routing
Alternate path routing
709238, 709242, G06F 1300
Patent
active
059319160
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a multi-processor environment and more particularly to arrangements for transferring data between processes running in such environments.
2. Related Art
In complex systems, such as a telephone network for example, "intelligence" is present at many different points. A number of control processors provide the main functionality of the network, however, substantial processing capability also exists away from the central offices.
In particular, intelligent peripherals, that is peripherals including data processing decision-making capability will be present at the locations closer to the customer.
Facilities to be provided by an intelligent peripheral may not require the establishment of a physical connection through a particular network. Thus, some such intelligent peripherals may represent a node on several different operating networks. Further, where a network comprises a number of host computers, a process on one of the hosts may need to interact directly with a process on another.
Accordingly inter-process communications between processes running on different hosts must be reliable.
While permanent links between processes are reliable they represent substantial investment and are inflexible. Host computers are therefore more usually accessed through shared public networks such as the Internet.
The Internet provides a simple datagram facility to allow data to be transferred between host processes. The transfers use a simple user datagram protocol (UDP) provided by the Internet. Such a protocol is described, for example, by Postel, J in ARPANET Working Group Request for Comments number 768. While permitting a data transfer between processes the UDP datagram is not as reliable a method of transferring data on fixed or PSTN links.
Previous datagram transfer facilities including that known as TCP many result in break up of the data contained within the datagram since it does not preserve message boundaries and may take a considerable time to notify any failure of delivery, if indeed such notification is possible.
SUMMARY OF THE INVENTION
The present invention therefore seeks to provide a method of reliably transferring data across Internet type networks.
According to the present invention there is provided a method of transferring data packets between processes running in a multi-processor environment of the kind comprising a plurality of host computers each accessible at a plurality of network node addresses, the method comprising: establishing for each process to be addressed a destination host identity and a destination host port, establishing for each destination host identity an address list comprising a plurality of corresponding network node addresses, for each transmission of a data packet selecting from the respective address list for the destination host a network node address being the next address cyclically in the list to the last address used for transmission between the nodes, adding to the data packet a header defining the selected network node address and the destination port, monitoring return data for packet acknowledgement and retransmitting any data packet not so acknowledged to the next network node address in the address list.
Each message header sent between processes may include a message sequence number which is incremented by the transmitting processor such that the receiving processor may re-assemble messages in the correct order and identify the absence of one or more messages in a sequence of messages.
For longer data packets the header may also include a fragment number in respect of the particular data packet being transmitted. Where more than one process on a first host computer is interacting with one or more processes on a second host computer, the sequence number represents messages transferred between nodes and may not be in sequence with the fragment number which represents a series of port-messages being transferred between processes to enable the re-assertion of a complete message p
REFERENCES:
patent: 4058672 (1977-11-01), Crager et al.
patent: 4901312 (1990-02-01), Hui et al.
patent: 4947389 (1990-08-01), Eng et al.
patent: 5088032 (1992-02-01), Bosack
patent: 5260933 (1993-11-01), Rouse
patent: 5293488 (1994-03-01), Riley et al.
patent: 5432907 (1995-07-01), Picazo, Jr. et al.
patent: 5541911 (1996-07-01), Nilakantan et al.
Barker Richard J.
Chapman James C. T.
Lucking Andrew M.
British Telecommunications public limited company
Luu Le Hien
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