Access to telecommunications networks in multi-service environment

Claims

What is claimed is:

1. A method of interfacing one or more CPEs and communications networks which encompass one or more PSTN, data networks, wireless networks, satellite networks, CATV, ATM networks and other communications networks, through local access to form a universal services network comprising steps of:

extracting information content from traffic to determine requested services of said traffic at the local access between the one or more CPEs and the communications networks;

prior to interfacing, determining one or more appropriate networks among the communications networks or one or more appropriate CPEs, both of which support the requested services, according to the requested services; and

routing the traffic directly either to the one or more appropriate networks among said one or more PSTN, data networks, wireless networks, satellite networks, CATV, ATM networks and other communications networks or to the one or more appropriate CPEs to complete interfacing between said appropriate CPEs and appropriate service providers and/or network resources.

2. The method according to claim 1 comprising a further step of:

an access module placing the local access in default mode in which the CPE forms part of the service provider environment and the access module is ready to receive or deliver traffic in a non-channelized format to and from the CPE.

3. The method according to claim 2 comprising a further step of:

the access module placing the local access in an alternate mode other than the default mode in which traffic in a channelized format is sent to and from the CPE.

4. The method according to claim 3 comprising a further step of:

the access module toggling between the default and the alternate modes in response to the extracted information content.

5. The method according to claim 4 wherein the extracted information content contains a prompt generated by the CPE, service providers, and/or network resources to activate the toggling of modes.

6. The method according to claim 5 comprising a further step of:

storing the extracted information content at the access module for later delivery of services.

7. The method according to claim 4 comprising further steps of:

converting the address and/or protocol of the traffic in reference to an address correlation table and/or a protocol conversion table, to which tables the access module has reading privileges; and

routing the extracted information content to appropriate network resources, service providers and/or one or more destinations according to the converted address and/or protocol.

8. The method according to claim 7 wherein there are one or more dissimilar CPEs connected to the local access, comprising a further step of:

the access module delivering and/or receiving traffic to and/or from an appropriate CPE according to user profiles to which the access module has reading privileges.

9. The method according to claim 8 comprising a further step of:

storing the extracted information content at the access module for later delivery of services.

10. The method according to claim 4 comprising further steps of:

converting the address and/or protocol of the traffic in reference to an address correlation table and/or a protocol conversion table, to which tables the access module has reading privileges; and

routing the extracted information content to appropriate network resources, service providers and/or one or more destinations according to the converted address and/or protocol in response to network status information obtained from the network resources or a request from the CPE.

11. The method according to claim 10 wherein there are one or more dissimilar CPEs connected to the local access, comprising a further step of:

the access module delivering and/or receiving traffic to and/or from an appropriate CPE according to user profiles to which the access module has reading privileges.

12. The method according to claim 11 comprising a further step of:

storing the extracted information content at the access module for later delivery of services.

13. The method according to claim 3 comprising a further step of:

the access module placing the local access in a dual-mode operation in which the default mode and alternate mode exist simultaneously.

14. The method according to claim 13 comprising further steps of:

converting the address and/or protocol of the traffic in reference to an address correlation table and/or a protocol conversion table, to which tables the access module has reading privileges; and

routing the extracted information content to appropriate network resources, service providers and/or one or more destinations according to the converted address and/or protocol.

15. The method according to claim 14 wherein there are one or more dissimilar CPEs connected to the local access, comprising a further step of:

the access module delivering and/or receiving traffic to and/or from an appropriate CPE according to user profiles to which the access module has reading privileges.

16. The method according to claim 15 comprising a further step of:

storing the extracted information content at the access module for later delivery of services.

17. The method according to claim 13 comprising further steps of:

converting the address and/or protocol of the traffic in reference to an address correlation table and/or a protocol conversion table, to which tables the access module has reading privileges; and

routing the extracted information content to appropriate network resources, service providers and/or one or more destinations according to the converted address and/or protocol in response to network status information obtained from the network resources or a request from the CPE.

18. The method according to claim 17 wherein there are one or more dissimilar CPEs connected to the local access, comprising a further step of:

the access module delivering and/or receiving traffic to and/or from an appropriate CPE according to user profiles to which the access module has reading privileges.

19. The method according to claim 18 comprising a further step of:

storing the extracted information content at the access module for later delivery of services.

20. The method according to claim 1 comprising a further step of:

an access module and a CPE connector placing the non-channelized local access therebetween in default mode in which the CPE forms part of the service provider environment and the access module is ready to deliver or receive traffic in a non-channelized format to and from the CPE.

21. The method according to claim 20 comprising a further step of:

an access module and a CPE connector placing the local access therebetween in an alternate mode other than the default mode in which traffic in a channelized format is sent to and from the CPE.

22. The method according to claim 21 comprising a further step of:

the access module toggling between the default and the alternate modes in response to the extracted information content.

23. The method according to claim 22 wherein the extracted information content contains a prompt generated by the CPE, service providers and/or network resources to initiate the toggling of the mode.

24. The method according to claim 23 comprising a further step of:

storing the extracted information content at the access module for later delivery of services.

25. The method according to claim 22 comprising further steps of:

the access module and/or the CPE connector converting address and/or protocol of the traffic in reference to an address correlation table and/or a protocol conversion table, to which tables the access module and/or CPE connector have reading privileges; and

routing the extracted information content to appropriate network resources, service providers and/or one or more destinations according to the converted address and/or protocol.

26. The method according to claim 25 wherein there are one or more dissimilar CPEs connected to the CPE connector, comprising a further step of:

the access module or CPE connector delivering and/or receiving traffic to or from an appropriate CPE according to user profiles to which the access module or CPE connector has reading privileges.

27. The method according to claim 26 comprising a further step of:

storing the extracted information content at the access module for later delivery of services.

28. The method according to claim 22 comprising further steps of:

the access module or CPE connector converting the address and/or protocol of the traffic in reference to an address correlation table and/or a protocol conversion table, to which tables the access module or CPE connector has reading privileges; and

the access module or CPE connector routing the extracted information content to appropriate network resources, service providers and/or one or more destinations according to the converted address and/or protocol in response to network status information obtained from the network resources or a request from the CPE.

29. The method according to claim 28 wherein there are one or more dissimilar CPEs connected to the CPE connector, comprising a further step of:

the access module or CPE connector delivering and/or receiving traffic to or from an appropriate CPE according to user profiles to which the access module or CPE connector has reading privileges.

30. The method according to claim 29 comprising a further step of:

storing the extracted information content at the access module for later delivery of services.

31. The method according to claim 21 comprising a further step of:

the access module placing the local access in a dual mode operation in which the default mode and the alternate mode exist simultaneously.

32. The method according to claim 31 comprising further steps of:

the access module and/or the CPE connector converting the address and/or protocol of the traffic in reference to an address correlation table and/or a protocol conversion table, to which tables the access module and/or CPE connector have reading privileges; and

routing the extracted information content to appropriate network resources, service providers and/or one or more destinations according to the converted address and/or protocol.

33. The method according to claim 32 wherein there are one or more dissimilar CPEs connected to the CPE connector, comprising a further step of:

the access module or CPE connector delivering and/or receiving traffic to or from an appropriate CPE according to user profiles to which the access module or CPE connector has reading privileges.

34. The method according to claim 33 comprising a further step of:

the access module and the CPE connector dynamically negotiating the use of the local access.

35. The method according to claim 34 comprising a further step of:

storing the extracted information content at the access module for later delivery of services.

36. The method according to claim 31 comprising further steps of:

the access module or CPE connector converting the address and/or protocol of the traffic in reference to an address correlation table and/or a protocol conversion table, to which tables the access module or CPE connector has reading privileges; and

the access module or CPE connector routing the extracted information content to appropriate network resources, service providers and/or one or more destinations according to the converted address and/or protocol in response to network status information obtained from the network resources or a request from the CPE.

37. The method according to claim 36 wherein there are one or more dissimilar CPEs connected to the CPE connector, comprising a further step of:

the access module or CPE connector delivering and/or receiving traffic to or from an appropriate CPE according to user profiles to which the access module or CPE connector has reading privileges.

38. The method according to claim 37 comprising a further step of:

the access module and the CPE connector dynamically negotiating the use of the local access.

39. The method according to claim 38 comprising a further step of:

storing the extracted information content at the access module for later delivery of services.

40. The method according to claim 31 comprising a further step of:

the access module and the CPE connector dynamically negotiating the use of the local access.

41. The method according to claim 40 comprising a further step of:

storing the extracted information content at the access module for later delivery of services.

42. An access module for interfacing with a CPE including a CPE modem functionality and communications networks which encompass one or more PSTN, data networks, wireless networks, satellite networks, CATV, ATM networks and other communications networks by way of a local access to form a universal services network, comprising:

a line interface for interfacing between the local access and the communications networks, the line interface including an access modem functionality to communicate with the CPE modem functionality;

a processor for extracting the information content from traffic for services;

a storage for storing information concerning user profiles, the services provided by the service providers, an address correlation table or a protocol conversion table; and

a controller for determining the routing, converting the address and/or the protocol and routing the extracted information content and/or protocol altered information content to appropriate network resources and one or more similar or dissimilar CPEs according to the information stored in the storage, a CPE request, or network status information obtained from the network resources.

43. The access module according to claim 42 wherein the access modem functionality is configurable according to the requirements of the resources of the local access.

44. The access module according to claim 43 wherein:

the access module has a default mode in which the CPE modem functionality and access modem functionality communicate with each other to receive or deliver traffic in a non-channelized format to and from the CPE; and

an alternate mode in which the CPE modem functionality and access modem functionality are bypassed to support traffic in a channelized format to and from the CPE.

45. The access module according to claim 44 further comprising:

a toggling circuit for toggling between the alternate and default modes.

46. The access module according to claim 45 wherein the local access is a pair of copper wires.

47. The access module according to claim 46 further comprising a memory device for storing the extracted information content for later delivery of services.

48. The access module according to claim 47 wherein the access module and the CPE have companion transceivers and exchange signals over the pair of copper wires in 2B1Q code for one or more similar and/or dissimilar services.

49. The access module according to claim 45 wherein the local access is a coax cable, fiber optics or wireless.

50. The access module according to claim 49 further comprising a memory device for storing the extracted information content for later delivery of services.

51. A local CPE access network for interfacing CPEs and communications networks which encompass one or more PSTN, data networks, wireless networks, satellite networks, CATV, ATM networks and other communications networks by way of a local access to form a universal services network comprising:

a CPE connector interfacing the CPEs and the local access and including a CPE modem functionality and a controller; and

the access module according to claim 45 wherein the controller of the CPE connector and the processor of the access module negotiate dynamically for the use of resources of the local access for one or more similar and/or dissimilar services in the default or alternate mode.

52. The local CPE access network according to claim 51 wherein:

the local access is a pair of copper wires; and

the CPE connector and the access module have companion transceivers for one or more similar and/or dissimilar services.

53. The local CPE access network according to claim 52 wherein the CPE connector and/or the access module further includes a memory device for storing the extracted information content for later delivery of services.

54. The local CPE access network according to claim 53 wherein the access module and the CPE connector have companion transceivers and exchange signals over the pair of copper wires in 2B1Q code for one or more similar and/or dissimilar services.

55. The local CPE access network according to claim 51 wherein:

the local access is a coax cable, fiber optics or wireless; and

the CPE and the access module have companion coax, fiber optic or wireless transceivers for one or more similar and/or dissimilar services.

56. The local CPE access network according to claim 55 wherein the CPE connector and/or the access module further includes a memory device for storing the extracted information content for later delivery of services.

57. The access module according to claim 44 further comprising:

the CPE and the access module have companion transceivers for activating a dual-mode operation in which the default mode and alternate mode exist simultaneously.

58. The access module according to claim 57 wherein the local access is a pair of copper wires.

59. The access module according to claim 58 further comprising a memory device for storing the extracted information content for later delivery of services.

60. The access module according to claim 59 wherein the CPE and the access module have companion transceivers and exchange signals over the pair of copper wires in 2B1Q code for one or more simultaneous similar and/or dissimilar services.

61. The access module according to claim 57 wherein:

the local access is a coax cable, fiber optics or wireless; and

the CPE and the access module have companion coax, fiber optic or wireless transceivers for one or more simultaneous similar and/or dissimilar services.

62. The access module according to claim 61 further comprising a memory device for storing the extracted information content for later delivery of services.

63. A local CPE access network for interfacing CPEs and communications networks which encompass one or more PSTN, data networks, wireless networks, satellite networks, CATV, ATM networks and other communications networks by way of a local access to form a universal services network comprising:

a CPE connector interfacing the CPEs and the local access and including a CPE modem functionality and a controller; and

the access module according to claim 57 wherein the controller of the CPE connector and the processor of the access module negotiate dynamically for the use of resources of the local access for one or more simultaneous, similar and/or dissimilar services in the dual mode operation.

64. The local CPE access network according to claim 63 wherein:

the local access is a pair of copper wires; and

the CPE connector and the access module have companion transceivers for one or more simultaneous similar and/or dissimilar services.

65. The local CPE access network according to claim 64 wherein the CPE connector and/or the access module further includes a memory device for storing the extracted information content for later delivery of services.

66. The local CPE access network according to claim 65 wherein the CPE connector and the access module have companion transceivers and exchange signals over the pair of copper wires in 2B1Q code for one or more simultaneous, similar and/or dissimilar services.

67. The local CPE access network according to claim 63 wherein:

the local access is a coax cable, fiber optics or wireless; and

the CPE connector and the access module have companion coax, fiber optic or wireless transceivers for one or more simultaneous similar and/or dissimilar services.

68. The local CPE access network according to claim 67 wherein the CPE connector and/or the access module further includes a memory device for storing the extracted information content for later delivery of services.

FIELD OF THE INVENTION

The present invention relates to a multi-service access platform which permits the formation of a universal service network encompassing a plurality of telecommunication networks. The invention relates particularly to a multi-service platform which allows a plurality of CPEs accessing any services provided by a plurality of service providers which may utilize any of the plurality of telecommunication networks.

BACKGROUND OF THE INVENTION

Facsimile machines and other data handling customer premise equipment are introduced not only into offices but individual homes in great numbers. As personal computers are found in more homes, users of computer networks such as "Internet" by way of telephone networks through modems are increasing in phenomenal numbers. The majority of these data transactions through modems or fax machines use existing local exchange carrier networks for data transmission. Fax machines, computers, and telephone sets at a customer premise are connected by local access to a central telephone switching office. The local access is variously called as subscriber's loop, local loop, drop etc. In cases of CATV or wireless, local access is also called subscriber connection, wireless access etc. It has been shown that the majority access "Internet" by dial-up telephone connection. FIG. 1 shows how a telephone, fax computer and other intelligent agents are typically connected through a publicly switched telephone network and data networks and their interconnections. Terminal equipment at a customer premise consist of a telephone set, fax machine, a personal computer etc., and are collectively called CPE which stands for customer premise equipment. CPE 10 is connected through inside wiring 12 at the customer premise and then through the feeder/distribution plant (also called subscriber's loop, local access loop) 14 to an access module (e.g. linecard) 16. The linecard is in turn connected to a local switch 18 that is part of the public switched telephone network (PSTN) 20. PSTN operates in channelized mode and provides continuous connection to another subscriber 22. The telephone service is established through a connection protocol (e.g. dialup, on-hook/off-hook protocol) and upon connection provides fixed channelized bandwidth on a continuous basis for the duration of the call. A facsimile connection is essentially the same as a telephone connection with the exception of the presence of a modem 24 at each facsimile terminal. The figure also shows a connection involving a data network. For such a connection, the CPE (e.g. computer) also requires a telephone subscriber's loop to the PSTN by dialup service which connects to a data service provider 26 through its own subscriber's loop 28. The data service provider 26 then provides a data connection through a data network 30 to a database service or other data service subscribers.

The present CATV service is mainly unidirectional, broadcast from a service provider through its own network which has no connection to any other network. In small scale, experimental multimedia telecommunications networks are being field tested at some locations. Referring to FIG. 2, such CATV access to telecommunications services is illustrated. In the figure, the CPE (e.g. TV) is connected through local wiring (possibly coax or fiber optic) to a converter 40, sometimes called a set-top box, that connects to the drop cable, taps, and splitters to a CATV access module 42 through an access loop 44 (most likely fiber optic or coax) and then through to the CATV services provider (cableco) 46 or other services providers 48 at which point connections to other service networks 50 can be provided. It is common for each subscriber to require a separate bidirectional channel for two-way telecommunications services. FIG. 2 also shows a wireless connection. For wireless service, the CPE is connected through the wireless interface or CPE connector 40 and a radio frequency channel 52 to a base station or access module 42, and then to the wireless services provider who in turn provides a connection to the specific service or transport network such as PSTN 54. During the entire call, a fixed amount of channel bandwidth is allocated to the service even though the specific radio frequency channel may change in a seemingly uninterrupted manner during the call.

In all these cases, the CPE is provided with channelized access of a fixed bandwidth, which makes it difficult to provide other services or to change service parameters during the time that the connection is established.

Computer connections are generally much longer in duration than voice or other connections. Computers perform data transactions in packets and their traffic is very bursty. The bursty traffic is more suitable for statistical multiplexing and is most efficiently handled by specially designed data networks such as packet switched networks. At present, however, all publicly switched traffic, data and voice, is sent over the subscriber's loop and interoffice trunking in a circuit switched network connection to destination customer premise equipment or to a data network.

Multimedia broadband switched networks by the name of the "Information Superhighway" have been widely proposed. This superhighway may carry different types of traffic seamlessly, accepting voice, data and video information from any terminal and delivering it to any other terminals simultaneously. At present, however, different types of networks, both channelized and packetized, exist separately and independently.

In circuit switched networks, a connection is maintained during the whole duration of a call through switches and other associated network elements, regardless of the type of the call. Only one circuit switched connection can be maintained for the call. No broadcast or multicast through the circuit switched network is possible. Today, telephone networks are becoming increasingly more occupied by data traffic which generates no additional revenues to the local exchange carriers. Furthermore, access to worldwide computer networks, such as "Internet" etc. is now being provided by commercial network service providers, such as America Online", "SprintLink" etc. Using PSTN as the access, the network service providers provide access to various other private networks, academic networks etc., which contain vast numbers of databases for value added services.

FIG. 3 shows diagrammatically how data networks such as "Internet" are accessed through a telephone subscriber's loop. An individual end user subscribes to the service of a commercial network service provider 60. Access to a data network is usually by dialing the telephone number of a commercial data network service provider using a modem. Thus the end user CPE 62 uses a modem and makes a dialup connection to a local switch 64 by a subscriber's loop 66. The local switch 64 makes an inter-office trunk connection 68 to a terminating local switch 70 within a PSTN 72. The terminating local switch connects through a local loop 74 and a terminating modem to a service provider 60. After a proper modem handshaking protocol, the user inputs the address of a destination such as the "Internet" server with whom he desires a connection. Data networks and database services are accessed using a TCP/IP protocol. The "Internet" packet is routed over a T-1 link 76 (or other facilities) to the Internet 78. In this arrangement, the local switches 64 and 70 as well as the interoffice trunk 68 are occupied for the duration of the connection, which is usually measured in hours rather than the shorter holding time associated with voice calls which are measured in minutes. Consequently, very expensive common equipment in the PSTN is required for the duration of the "Internet" access, even during a period of inactivity by the end user.

The use of a telephone network by network service users increases usage of the telephone network enormously without a proportionate increase of additional revenues to the telephone company. It is also cumbersome for an individual user to access various networks. It will be shown below that the present invention reduces this investment in the PSTN (31) as well as enhances the capabilities of the overall global communications network.

There have been many patents which address network data transfer issues. For example, U.S. Pat. No. 4,178,480, issued Dec. 11, 1979 (Carbrey) describes a single multiplexing circuit which permits use between a central communication system and a remote communication circuit for concurrently transmitting outgoing voice signals, outgoing data, and outgoing auxiliary signals from the remote communication circuit to the central communication system via a single pair of wires. Voice signals are audio signals in the voice frequency band. Input and output data streams comprise periodic bursts of bipolar pulses of PAM transmitted in the voice band and the auxiliary signals are bipolar pulses of PWM format transmitted also in the voice band but during a silent period of data signals.

U.S. Pat. No. 4,608,686, issued August 26, 1986 (Barselloti) describes a circuit for transmitting both voice and data at the same time between a subscriber's set and a switching exchange via a bidirectional wire link.

U.S. Pat. No. 5,410,754, issued Apr. 25, 1995 (Klotzbach et al) teaches an interface between a wire-line carrier system and a remote host on a LAN. The interface includes a protocol conversion between PCM data and TCP/IP packet data.

U.S. Pat. No. 5,267,301, issued Nov. 30, 1993 (Nishii) is directed to an interfacing device for discriminate voice and fax signals.

U.S. Pat. No. 4,903,263, issued Feb. 20, 1990 (Patel) relates to an adjunct device to existing switches for providing ISDN capabilities.

Hereinafter, the following terms will be used in connection with the description of the invention.

Network access (local access network)--A managed facility between the CPE and communications networks (e.g. copper pairs, coaxial, fiber, wireless).

Channelized protocol--Communications protocol requiring end-to-end allocation of network resources of a specified bandwidth for the duration of the session, independent of the actual information transfer activity (e.g. a circuit switched network, such as PSTN implements a channelized protocol for telephone traffic).

Non-channelized protocol--Communications protocol allocating network resources for the duration of actual information transfer activity (e.g. a packet switched network implements a non-channelized protocol for transfer of signals).

Traffic in channelized format--Communications traffic using a channelized protocol.

Traffic in non-channelized format--Communications traffic using a non-channelized protocol.

OBJECTS OF THE INVENTION

It is an object of the invention to provide better utilization of CPE by providing an intelligent connection to multiple types of service and non-service specific transport networks in multiple protocol environments.

It is a further object of the invention to provide a system which allows a simpler, more transparent delivery of information on an end-to-end basis.

It is yet another object of the invention to provide a system for optimized throughput of existing access pipes according to specific service needs.

It is still another object of the invention to provide a system having improved functionalities between the CPE and access or service provider's LANs.

It is a further object of the invention to provide a flexible access system to utilize any transport network resource on a service-by-service basis;

It is yet a further object of the invention to provide a system which enables simultaneous multiple service delivery over the access network.

It is another object of the invention to provide a system which can perform an alternate routing of services among transport networks.

It is yet another object of the invention to provide a system which enables customer service and feature control by individual service.

SUMMARY OF THE INVENTION

Briefly stated, according to one aspect, the invention relates to a method of interfacing CPEs and communications networks which encompass one or more PSTN, data networks, wireless networks, satellite networks, CATV, ATM networks and other communications networks, through local access to form a universal services network. The method comprises a step of extracting information content from traffic to determine requested services of said traffic at the local access between the CPEs and the communications networks. The method further includes steps of determining appropriate routing prior to interfacing CPEs and the communications networks, according to the extracted information content, and routing the extracted information content directly either to said one or more PSTN, data networks, wireless networks, satellite networks, CATV, ATM networks and other communications networks or to any of said CPEs to complete interfacing between said CPEs and appropriate service providers and/or network resources.

According to another aspect, the invention is directed to an access module for interfacing a CPE including a CPE modem functionality and communications networks which encompass one or more PSTN, data networks, wireless networks, satellite networks, CATV, ATM networks and other communications networks by way of a local access to form a universal services network. The access module comprises a line interface for interfacing between the local access and the communications networks and a processor for extracting information content from traffic for services. The line interface includes an access modem functionality to communicate with the CPE modem functionality. The access module further includes a storage for storing information concerning user profiles, the services provided by the service providers, an address correlation table or a protocol conversion table, and a controller for determining the routing, converting the address and/or the protocol, and routing the extracted information content and/or protocol altered information content through appropriate network resources and one or more similar or dissimilar CPEs according to the information stored in the storage, a CPE request, or network status information obtained from the network resources.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows access to service providers such as public switched network and data networks service providers;

FIG. 2 shows CATV access to some other service providers;

FIG. 3 is a schematic illustration of a presently used "Internet" access;

FIG. 4 shows a connection through a circuit switched network using POTS calling protocol;

FIG. 5 shows connections through a circuit switched network and data switched network using ISDN calling protocol;

FIG. 6 shows connections through a circuit switched network and a data switched network using both ISDN and POTS calling protocols;

FIG. 7 shows access to various service providers according to the invention;

FIG. 8 shows in detail a CPE connector and an access module in a local access network according to one embodiment;

FIGS. 9-11 show various configurations in which the local access network of the invention is used; and

FIGS. 12-15 show in detail a CPE connector and an access module according to other embodiments of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION

FIG. 4 is a simple illustration of how telephone sets and computers are connected through today's PSTN, which is a circuit switched network of which, in this case, two local switches are shown. The calling protocol of a telephone is as follows: at a calling party, the off-hook is indicated by the telephone set (called POTS for plain old telephone set) 100 or by the modem 102 under the control of the computer 104 and is detected by a linecard 106. The local switch provides dial tone indicating that it is ready to receive the called party's telephone number. The digits dialed by the telephone set or modem represent the address of the called party and the switch provides a DS-0 channel between the two parties and applies ringing to the called party. In response to the ringing, a voice call can proceed when the called party's telephone set 108 goes off hook. Alternatively, the modem 110 at the called party can provide the off hook response to the ringing. The modem 110 under the control of its computer 112 performs an appropriate handshaking with the calling party's modem before data exchange can proceed. A subsequent on hook from either party indicates the termination of the call and the DS-0 connection is dropped. In this example, a modem appears to the local switch similar to a telephone set.

FIG. 5 shows diagrammatically how telephone sets and computers are connected through a PSTN in the known ISDN environment. An ISDN terminal 120 is connected by way of a network termination 122 to ISDN linecard 124 through a digital subscriber loop (DSL) 126. The ISDN terminal can be a computer or an ISDN telephone set, or a collection of them. The ISDN terminal sends a call request via a D channel packet specifying the address of the called ISDN party in accordance with the ISDN numbering plan (E.164 address). The D channel handler 128 at the local switch determines if the requested connection through the B channel is a circuit switched connection or a packet switched connection. The D channel handler can do this by checking the address of the called party. The circuit switched connection, e.g. voice (indicated by the called party's telephone number) is routed to another circuit switch which provides the access function to the called party. If the requested connection is a packet switched connection, the switch translates the address for data network routing and sends the request to the called party's terminal. The called party's terminal responds with an acceptance message. Subsequently, the data are passed through a DS-0 channel in the local switch serving the calling party to the data network and through a DS-0 channel in the local switch serving the called party to the called party's terminal.

FIG. 6 is an illustration of another known instance where a connection is desired between an ISDN terminal and an ordinary telephone or a computer, both connected through an analog subscriber loop. A circuit switched connection is set up in each direction and maintained in a similar fashion, as shown in FIGS. 4 and 5. If the call request is a packet switched connection, the calling ISDN terminal must specify the E.164 address of a network modem 140. The network modem prompts the ISDN