TDM backplane stream resource distribution system

• US 6,366,587 B1
• Filed: 08/31/1998
• Issued: 04/02/2002
• Est. Priority Date: 08/31/1998
• Status: Expired due to Term

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Systems, Inc.
• Inventors: Chu, Paul Ruey Perng
• Primary Examiner(s): Vincent, David R.
• Assistant Examiner(s): Phunkulh, Bob A.
• Application Number:
  US09/143,593
• Time in Patent Office: 1,310 Days
• Field of Search: 370/442, 370/458, 370/463, 370/400, 370/401, 370/468, 375/222
• US Class Current: 370/442
• CPC Class Codes: H04Q 11/0407 using a stored programme control
• CPC Class Codes: H04Q 2213/13003 Constructional details of switching devices
• CPC Class Codes: H04Q 2213/13076 Distributing frame, MDF, cross-connect switch
• CPC Class Codes: H04Q 2213/13107 Control equipment for a part of the connection, distributed control, co-processing
• CPC Class Codes: H04Q 2213/13109 Initializing, personal profile
• CPC Class Codes: H04Q 2213/13141 Hunting for free outlet, circuit or channel
• CPC Class Codes: H04Q 2213/13196 Connection circuit/link/trunk/junction, bridge, router, gateway
• CPC Class Codes: H04Q 2213/13199 Modem, modulation
• CPC Class Codes: H04Q 2213/13292 Time division multiplexing, TDM
• CPC Class Codes: H04Q 2213/13322 Integrated circuits
• CPC Class Codes: H04Q 2213/13396 Signaling in general, in-band signalling

Abstract

A preferred embodiment of the present invention is disclosed to include a router system having a trunk feature card and at least one modem feature card for transferring communication information between the modem feature cards through a TDM backplane, to the trunk card, for transfer thereof to Digital Subscriber (DS) lines, the router and modem cards while co-existing within the same router system, having no knowledge of the characteristics of each other with many different combinations of such trunk and modem cards being employed by the router system. The router system accommodating “over-subscription” situations wherein the number of DS lines is less than the number of modems and initialization the system such as to maximize the utility of the DS lines as a function of the type of modem cards in the system.

Claims

1. A digital communications system for coupling a plurality of digital communication devices to a central office comprising:

a backplane;

a trunk card device coupled to Digital Subscriber (DS) channels and further coupled to a first trunk group of streams and a second trunk group of streams, said first and second trunk streams for transferring modem information to and from said DS channels through said backplane; and

at least one modem card device having a predetermined number of modem units, said at least one modem card device coupled through a first modem group of streams and a second modem group of streams to said backplane for transferring modem information through said backplane to said DS channels, said at least one modem card device for controlling said predetermined number of modem units to transfer modem information between said modem units and said DS channels through said backplane,

wherein said modem units are dynamically allocated to transfer information, through said backplane, to said first and second trunk group of streams so as to maximize utilization of all of the modem units.

2. A digital communications system as recited in claim 1 wherein each of said streams includes a predetermined number of channels of communication, each said predetermined number of channels for communicating modem information to a particular modem unit.

3. A digital communications system as recited in claim 1 wherein the digital system is a router system.

4. A digital communications system as recited in claim 1 wherein said DS channels are Time Division Multiplixed (TDM) channels of communication.

5. A digital communications system as recited in claim 1 wherein said DS channels include a first group of Digital Subscriber (DS0) channels and a second group of Digital Subscriber (DS1) channels for selectably and dynamically allocating said first and second modem groups of streams to the central office.

6. A digital communications system as recited in claim 1 including a second modem card device coupled to said backplane through a first modem group of streams and a second modem group of streams.

7. A digital communications system as recited in claim 6 wherein the type of trunk device and modem devices determines the selectable assignment and dynamic allocation of said first and second modem group of streams to said first and second trunk streams for communication of modem information therethrough.

8. A digital communications system as recited in claim 7 wherein the type of trunk and modem devices is determined upon initialization of the system.

9. A digital communications system as recited in claim 8 wherein upon the determination that the trunk device is of the type to support at least two groups of modem streams, a predetermined assignment is utilized for assigning the trunk group of streams to the modem group of streams based upon which type of modem card device is the first to be identified by the system.

10. A method for use in a digital communications system for selectively coupling a plurality of digital communication devices to a central office, the digital communication system including a backplane, a trunk card device coupled to Digital Subscriber (DS) channels and further coupled to a first trunk group of streams and a second trunk group of streams for transferring modem information to and from said DS channels through said backplane, at least one modem card device coupled through a first modem group of streams and a second modem group of streams to said backplane for transferring modem information through said backplane to said DS channels, each modem card for controlling a predetermined number of modem units to transfer modem information between said modem units and said DS channels through said backplane, the method comprising:

providing a first modem card device and a second modem card device;

upon initialization of the digital system, detecting the type of trunk card in the digital system;

determining which type of modem device is the first modem card device;

determining which type of modem device is the second modem card device; and

based upon the type of trunk card detected and the determination of the type of device the first modem device is, selectively coupling the trunk card to the first and second modem cards so as to fully utilize all of the modem units accessible to the first and second modem cards.

11. A method for use in a digital communications system as recited in claim 10 wherein the step of determining which type of modem device the first modem device is, comprises a determination of the number of modem units that are to be accessed by the first modem device and the step of determining which type of modem device the second modem device is comprises a determination of the number of modem units that are to be accessed by the second modem device.

12. A method for use in a digital communications system as recited in claim 11 wherein the step of detecting the type of trunk card includes determining the number of DS channels coupled to the trunk card.

13. A digital communications system as recited in claim 10 wherein said DS channels include a first group of Digital Subscriber (DS0) channels and a second group of Digital Subscriber (DS1) channels for selectably coupling said first and second modem groups of streams to the central office.