Method and system for controlling a network of modems
First Claim
1. A method of controlling a network which includes a plurality of modems each operating at a data transmission rate of n bits per baud for normal data transmission where n has an integer value greater than one and comprises a data terminal equipment (DTE), a first modem, a signal conducting path interconnected between the said first modem and the said DTE for conducting both normal data and command messages, and a second modem attached to the first modem through a transmission medium, said method being characterized in that it includes the steps of:
- at said DTE as required terminating transmission of normal data over said signal conducting path and transmitting a command message having a plurality of digitally coded fields to the first modem over the said signal conducting path, said command message including a first identification field (H), an address field (AM), and a command field (C),at said first modem monitoring said signal conducting path to detect said first identification field of said command message,in response to detecting said identification field storing the command field received over said path when said address field contains the address of said first modem,reformatting the received command message to obtain a first supervisory message in which said first identification field is replaced by a second identification field (SH), when said command field specifies a command intended for said second modem, andsending in succession over said transmission medium a startup sequence and said first supervisory message, with the latter being sent one bit per baud regardless of the data transmission rate n at which said first and second modems exhange normal data.
3 Assignments
0 Petitions
Accused Products
Abstract
A DTE can control the modems attached thereto by transmitting command messages over the data path and analyzing report messages supplied by the modems in return. Each command message is identified by a specific header. A command message intended for a remote modem (34) is intercepted by the local modem (30) and reformatted so as to obtain a supervisory message that is then transmitted at the rate of one bit per baud. A command message intended for a remote multichannel modem (48) is transmitted either by a supervisory message or in the data mode of operation.
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Citations
11 Claims
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1. A method of controlling a network which includes a plurality of modems each operating at a data transmission rate of n bits per baud for normal data transmission where n has an integer value greater than one and comprises a data terminal equipment (DTE), a first modem, a signal conducting path interconnected between the said first modem and the said DTE for conducting both normal data and command messages, and a second modem attached to the first modem through a transmission medium, said method being characterized in that it includes the steps of:
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at said DTE as required terminating transmission of normal data over said signal conducting path and transmitting a command message having a plurality of digitally coded fields to the first modem over the said signal conducting path, said command message including a first identification field (H), an address field (AM), and a command field (C), at said first modem monitoring said signal conducting path to detect said first identification field of said command message, in response to detecting said identification field storing the command field received over said path when said address field contains the address of said first modem, reformatting the received command message to obtain a first supervisory message in which said first identification field is replaced by a second identification field (SH), when said command field specifies a command intended for said second modem, and sending in succession over said transmission medium a startup sequence and said first supervisory message, with the latter being sent one bit per baud regardless of the data transmission rate n at which said first and second modems exhange normal data. - View Dependent Claims (2, 3, 4, 5)
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6. A method of controlling a network which includes a plurality of modems each operating at a data transmission rate of n bits per baud for normal data transmission where n has an integer value greater than one and comprises a data terminal equipment (DTE), a first multichannel modem including a base modem and a plurality of channels, a signal conducting path interconnected between each channel of the said first modem and the said DTE each for conducting both normal data and command messages, a second multichannel modem including a plurality of channels and a base modem, a transmission medium interconnecting the base modems of said first and second multichannel modems, said method being characterized in that it includes the steps of:
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at said DTE as required terminating transmission of normal data over one of said signal conducting paths and transmitting a command message having a plurality of digitally coded fields to the first modem over the said one signal conducting path, said command message including a first identification field (H), an address field (AM), a transmission mode indicator, and a command field (C), at said first modem monitoring said one signal conducting path to detect said first identification field of said command message, in response to detecting said identification field storing the command field received over said path when said address field contains the address of said first multichannel modem, reformatting the received command message to obtain a first supervisory message in which said first identification field is replaced by a second identification field (SH), and to which is appended a second address field (CH) identifying the channel of said first multichannel modem that received the command message, when said transmission mode indicator specifies a first transmission mode and said command field specifies a command intended for said second multichannel modem, and transmitting in succession over said transmission medium a startup sequence and said first supervisory message, with said first supervisory message being transmitted one bit per baud regardless of the signalling rate n at which said first and second multichannel modems exchange normal data. - View Dependent Claims (7, 8, 9)
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10. A system of controlling a network which includes a plurality of modems each operating at a signalling rate of n bits per baud for normal data transmission where n has an integer value greater than one:
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a data terminal equipment (DTE); a first modem; a signal conducting path interconnected between the said first modem and the said DTE for conducting both normal data and command messages; a second modem, a transmission medium interconnecting the first and second modems; first means (12) at said DTE for generating a command message including first identification field (H), an address field (AM) and a command field (C), and for transmitting said command message to said first modem over the said signal conducting path (TD); first detection means (108, 114,
116) at said first modem connected to said signal conducting path for monitoring said path and for intercepting a command message thereon, in response to the detection of a first identification field on the said signal conducting path, and if said address field contains the address of the first modem;second means (114) at said first modem for storing the command message received from said path; control means (101, 150,
152) at said first modem for decoding the command field in the stored command message and for generating a first supervisory message derived from the command message, and in which the first identification field is replaced by a second identification field (SH), when the command field contained in the first supervisory message specifies a command intended for the said second modem,third means (158) at said first modem for storing the first supervisory message; and fourth means (XMIT, 160, 108,
104) at said first modem for successively transmitting over the transmission medium a startup sequence and the first supervisory message, said first supervisory message being transmitted at one bit per baud regardless of the rate n at which normal data are exchanged between said first and second modems. - View Dependent Claims (11)
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Specification