Packet transmission system having timer for circuit disconnection
AssigneeNEC Corporation
InventorAtsushi Yoshida
Life of this patent
Estimating the term…
Abstract
A packet transmission system comprises a routing processor and data-circuit terminating equipment (DCE) for transmitting data packets between a LAN and a public network, and further includes a table where timer set values corresponding to types of data packet protocol are stored in advance, and a timer which starts counting at the time of packet termination and stops counting when its count value reaches a selected timer set value. The table selects one of the timer set values based on the type of a data packet to be transmitted from the LAN to the public network. The timer outputs a disconnection signal to the DCE when its count value reaches the selected timer set value.
Claims12
A packet transmission system having a routing function to transmit packets between a first network and a second network, said packets being based on a TCP/IP (Transmission Control Protocol/Internet Protocol) specification, said packet transmission system comprising:
- storage means for storing a plurality of time set values corresponding to a plurality of upper protocols, respectively, said upper protocols operating in layers higher than TCP (Transmission Control Protocol);
- reading means for reading a time set value from said storage means corresponding to an upper protocol specified by a packet to be transmitted between said first network and said second network;
- transmission termination detecting means for detecting termination of packet transmission between said first network and said second network;
- timer means for measuring elapsed time from the detection of said termination of packet transmission;
- and
- control means for disconnecting said first network from said second network when said elapsed time measured by said timer means reaches said time set value which was read out from said storage means by said reading means.
An apparatus having a routing processor and data-circuit terminating equipment for transmitting packets between a local area network (LAN) and a public network, said packets being based on a TCP/IP (Transmission Control Protocol/Internet Protocol) specification, said apparatus comprising:
- storage means for storing a plurality of time set values corresponding to a plurality of upper protocols, respectively, said upper protocols operating in layers higher than TCP (Transmission Control Protocol);
- reading means for reading a time set value from said storage means according to an upper protocol specified by a packet to be transmitted from said LAN to said public network;
- transmission termination detecting means for detecting termination of packet transmission between said LAN and said public network;
- a timer which starts operating when said termination of packet transmission is detected;
- and
- comparison means for comparing an output of said timer with said time set value, said comparison means outputting a public-circuit disconnection signal to said data-circuit terminating equipment when said output of said timer reaches said time set value.
A method of terminating a connection for transmitting packets between a first network and a second network, said packets being based on a TCP/IP (Transmission Control Protocol/Internet Protocol) specification, said method comprising steps of:
- a) storing a plurality of time set values corresponding to a plurality of upper protocols, respectively, said upper protocols operating in layers higher than TCP (Transmission Control Protocol);
- b) selecting a time set value from said plurality of time set values according to an upper protocol specified by a packet to be transmitted between said first network and said second network;
- c) detecting termination of packet transmission between said first network and said second network;
- d) measuring a lapse of time after detection of said termination of packet transmission;
- and
- e) disconnecting said first network from said second network when said lapse of time reaches said time set value which was selected by said step (b).
Dependencies are inferred from the claim text.