Traffic control apparatus and method of user-network interface of asynchronous transfer mode

A local exchange for an integrated service digital network in an asynchronous transfer mode, comprising:

• connection control means responsive to a call upon occurrence of a call establishment request from a first subscriber to be connected with a second subscriber terminal, for identifying a traffic class of a traffic flow of cells representative of said call upon reception of traffic parameters described by said first subscriber terminal, for routing a communication path to a destination intended by said call in dependence upon said traffic parameters;
• first multiplexer means operatively connected to said connection control means, for multiplexing the traffic flow of cells into a single cell stream;
• traffic control means operatively connected to said connection control means, for making a determination of whether the single cell stream violates said traffic parameters described by said first subscriber terminal and for enabling execution of cell transmission, cell shaping, and cell discard in dependence upon said determination;
• switch means operatively connected to said traffic control means, for enabling transmission of the single cell stream;
• and
• second multiplexer means operatively connected between said switch means and said traffic control means, for transmitting the single cell stream having virtual path identifiers and virtual channel identifiers modified on a basis of a routing look-up table to another network.

A traffic control method for an integrated service digital network in an asynchronous transfer mode comprising traffic control routines for controlling a traffic flow of cells of different traffic classes, each class having data of fixed length indicative of one of voice data, real time image data, and general data, said traffic control method comprising:

• a connection control step for receiving and identifying a traffic class of traffic flow of cells representative of a call upon occurrence of a call establishment request from a first subscriber terminal to be connected with a second subscriber terminal for controlling admission of said call in dependence upon reception of traffic parameters described by said first subscriber terminal;
• a traffic control step for making a determination of whether the traffic flow of cells violates said traffic parameters described by said first subscriber terminal and for enabling execution of cell transmission, traffic shaping, and discard of cells in dependence upon said determination, said traffic control step comprising:
• monitoring the traffic flow of cells and determining a minimum cell interval time allowed for each virtual path;
• measuring a cell arrival time of the traffic flow of cells;
• storing a current cell arrival time and a previous cell arrival time;
• subtracting the current cell arrival time and the previous cell arrival time to produce a window time;
• determining that the traffic flow of cells violates said traffic parameters when the window time is smaller than the minimum cell interval time;
• counting the number of cells received;
• storing a current cell counter value and a previous cell counter value representative of a total bandwidth value assigned to each virtual path;
• determining the number of cells having identical virtual path identifier within the time window by subtracting the previous cell counter value from the current cell counter value;
• determining a current usage bandwidth of a current time window time based upon a reciprocal of a result of dividing the number of cells having identical virtual path identifier within the window time from the window time;
• enabling cell discard when the current usage bandwidth during the current window time is greater than the total bandwidth value;
• and
• enabling cell transmission when the current usage bandwidth during the current window time is not greater than the total bandwidth value;
• and
• a call transmission step for enabling transmission of the cells by statistically multiplexing said cells for outputting to an output route.

A traffic control method for a user-network interface of an asynchronous transfer mode comprising a broadband-terminal device, a broadband-network termination device having storage means for storing traffic control routines for traffic controlling different traffic classes of an inflow of cells with data of a fixed length representing a call, and traffic parameters described by a calling subscriber terminal for assisting the traffic control, said broadband-network termination device analyzing virtual path identifier and virtual channel identifier in a cell header of a cell output from said broadband-terminal device and controlling the inflow of cells, and a local exchange for fixedly assigning the virtual path identifier to said broadband-network termination device in accordance with the traffic parameters and controlling the traffic of the inflow of cells through the assigned virtual path identifier and virtual channel identifier, said traffic control method comprising:

• determining whether each cell from the inflow of cells violates the traffic parameters;
• a traffic parameter loading step for storing a cell header of a currently received cell in response to an input primitive, and combining virtual path identifier, virtual channel identifier and offset bits from the cell header to be loaded into a parameter storage area when the currently received cell does not violate the traffic parameters;
• and
• a traffic control step for controlling the traffic of each cell from the inflow of cells in accordance with different traffic classes representing one of voice data, image data and general data determined by information loaded in said parameter storage area.

A traffic control method for a user-network interface of an asynchronous transfer mode, said traffic control method comprising:

• a monitoring step having a minimum cell interval time established by a connection admission control for receiving and monitoring whether an incoming stream of cells representing a call from a first subscriber terminal violates traffic parameters described by said first subscriber terminal, upon reception of said call from said first subscriber terminal requesting a connection through a transmission line to a second subscriber terminal by storing a current cell arrival time and a previous cell arrival time generated from said first subscriber terminal and calculating a window time and comparing the window time with the minimum cell interval time, said window time being calculated by the following equation:
• window time W.sub.i (t-1,t)=current cell arrival time T(t)-previous cell arrival time .sub.i T(t-1),
• where T.sub.i (t) represents a current cell arrival time of a channel i, and T.sub.i (t-I) represents a previous cell arrival time of the channel i;
• and
• a bandwidth management step for controlling bandwidth assignment of the cells by counting the number of cells received, storing a previous cell counter value and a current cell counter value indicative of a value of a total assignment bandwidth assigned to a virtual path containing a current cell, extracting the number of cells having identical virtual path identifier within the window time by subtracting the current cell counter value from the previous cell counter value, extracting a current usage bandwidth during a current window time and comparing the current usage bandwidth with the total assignment bandwidth so as to assign said current usage bandwidth for transmission of the current cell, said current usage bandwidth during the current window time being calculated by the following equation:
• current usage bandwidth during current window time=1.div.(window time.div.the number of cells having identical virtual path identifier in the window time).