US 5,490,141 A · System and method for providing SVC service through an ATM network for frame relay DTEs with a terminal adapter

Abstract

The system and method of the present invention provide a seamless approach for providing ATM connectivity for a Frame Relay DTE using an intelligent Terminal Adapter (TA). Using the system and method of the present invention, an enhanced Frame Relay protocol runs between the DTE and the ATM TA, the Frame Relay DTE is provided with not only the connectivity to the ATM network but also the full advantages of ATM transport mechanism and, in particular, the connectivity through the ATM network using the SVC connection mechanism. Using the system and method of the present invention, a FR DTE may issue commands to the terminal adapter to set of calls, or connections, with other DTEs (FR or ATM). The terminal adapter then communicates with the ATM network and the destination DTE using the ANSI Q.2931 call establishment procedure (using commands such as Call.sub.-- Set-up, Call.sub.-- Accept, and Call.sub.-- Disconnect) to establish an SVC connection between the communicating DTEs. In addition, the FR DTE sends parameters such as quality of service (QOS), peak bandwidth, etc., so that the Frame Relay DTE can send real-time data, image, voice, or video traffics across the ATM network using the less expensive SVC mechanism.

Claims28

Dependent claims

For use with a frame relay terminating equipment (FR DTE) and an asynchronous transfer mode (ATM) network providing a Switched Virtual Circuit (SVC) service and having one or more communications units connected thereto, a terminal adapter for providing an interface to said ATM network for said FR DTE so that said FR DTE is able to communicate with at least one of said one or more communications units over said ATM network using said SVC service, said terminal adapter comprising:

a servicing element;
a FR DTE interface connected to said servicing element, said FR DTE interface comprising means for receiving frame relay (FR) frames from said FR DTE, said FR frames having a Data Link Connection Identifier (DLCI) field and a data field, at least one of said FR frames being an SVC frame and having a DLCI uniquely known by said terminal adapter, means for building information packets from said received FR frames, means for conveying said information packets to said servicing element;
and
an ATM network interface connected to said servicing element, said ATM network interface comprising means for receiving protocol data units (PDUs) from said servicing element, means for building ATM cells by segmenting said PDUs, and means for conveying said ATM cells to said ATM network,
said servicing element comprising means for receiving information packets from said FR DTE interface, means for examining the contents of said DLCI field and of said data field, means for building PDUs based upon the contents of said DLCI field and said data field, said PDU building means comprising means for recognizing said uniquely known DLCI of said SVC frame and for building a PDU representing an SVC command based upon the contents of said data field of said SVC frame, and means for conveying PDUs to said ATM network interface.

2 more elements

For use in a terminal adapter connected between a frame relay data terminating equipment (FR DTE) and an asynchronous transfer mode (ATM) network providing a Switched Virtual Circuit (SVC) service and having one or more communications units connected thereto, said terminal adapter providing an interface to said ATM network for said FR DTE so that said FR DTE is able to communicate with at least one of said one or more communications units via said SVC service, said terminal adapter comprising a servicing element, a FR DTE interface connected to said servicing element and an ATM network interface connected to said servicing element, said method comprising the steps of:

in said FR DTE interface, receiving frame relay (FR) frames from said FR DTE, said FR frames comprising a DLCI field and a data field, at least one of said FR frames being an SVC frame and having a DLCI value uniquely known by said terminal adapter, building information packets from said FR frames, and conveying said information packets to said servicing element;
in said ATM network interface, receiving protocol data units (PDUs) from said servicing element, and building ATM cells to be conveyed to said ATM network by segmenting said PDUs;
and
in said servicing element:
receiving information packets from said FR DTE interface;
examining said DLCI of each received packet and determining if the value of said DLCI is recognized as being unique;
if the DLCI value is unique, examining the contents of said data field;
building PDUs based upon the contents of said data field;
and
conveying PDUs to said ATM network interface.

7 more elements

For use with an asynchronous transfer mode (ATM) network providing a Switched Virtual Circuit (SVC) service and having one or more communications units connected thereto, a system for communicating with said one or more communications units over said ATM network using said SVC service comprising:

means for generating and conveying frame relay (FR) frames, said FR frames comprising a DLCI field and a data field, at least one of said FR frames being an SVC frame and having a DLCI uniquely known by said terminal adapter;
a servicing element;
an FR interface connected between said FR frame generating and conveying means and said servicing element, said FR inteface comprising means for receiving said FR frames from said FR frame conveying means, means for building an information packet from each FR frame received from said FR frame conveying means, and means for conveying said information packets to said servicing element;
and
an ATM network interface connected to said servicing element, said ATM network interface comprising means for conveying ATM cells to said ATM network, means for receiving protocol data units (PDUs) from said servicing element, and means for building ATM cells to be conveyed to said ATM network by segmenting said PDUs,
said servicing element comprising means for receiving information packets from said FR interface, means for examining the contents of said DLCI field and of said data field, means for building PDUs based upon the contents of said DLCI field and said data field, said PDU building means comprising means for recognizing said uniquely known DLCI of said SVC frame and for building a PDU representing an SVC command based upon the contents of said data field of said SVC frame, and means for conveying PDUs to said ATM network interface.

3 more elements

Dependencies are inferred from the claim text.

System and method for providing SVC service through an ATM network for frame relay DTEs with a terminal adapter

Life of this patent

System and method for providing SVC service through an ATM network for frame relay DTEs with a terminal adapter

Life of this patent

Abstract

Claims28