Multiple application switching platform and method

• US 6,381,239 B1
• Filed: 08/13/1998
• Issued: 04/30/2002
• Est. Priority Date: 02/13/1996
• Status: Expired due to Term

• Current Assignee: Ribbon Communications Operating Company, Inc. (Ribbon Communications, Inc.)
• Original Assignee: Taqua Systems, Inc. (Oracle Corporation)
• Inventors: Ashley, William, Klein, Raymond, Atkinson, Roger F., Beckman, Kenneth A., Ng, Simon S., Siefert, Robert J.
• Primary Examiner(s): Ton, Dang
• Application Number:
  US09/125,217
• Time in Patent Office: 1,356 Days
• Field of Search: 370/362, 370/342, 370/347, 370/341, 370/442, 370/389, 370/465, 370/466, 370/351, 370/352, 370/401, 370/402, 370/403, 370/350, 370/503, 370/216, 370/318, 370/363, 370/367, 370/368, 370/357, 370/321, 370/345, 370/468, 370/295, 379/93.05, 379/93.07, 379/93.09, 379/93.08
• US Class Current: 370/362
• CPC Class Codes: H04M 3/005 Interface circuits for subscriber lines current supply H04M19/00 and subgroups; supervisory, monitoring or testing arrangements H04M3/22 and subgroups; in key telephone systems H04M9/006
• CPC Class Codes: H04M 3/007 Access interface units for simultaneous transmission of speech and data, e.g. digital subscriber line [DSL] access interface units DSL access multiplexers H04Q11/0478, and H04L12/2856
• CPC Class Codes: H04M 9/025 Time division multiplex systems, e.g. loop systems
• 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 2213/1305 Software aspects
• CPC Class Codes: H04Q 2213/13103 Memory
• CPC Class Codes: H04Q 2213/13106 Microprocessor, CPU
• CPC Class Codes: H04Q 2213/13109 Initializing, personal profile
• CPC Class Codes: H04Q 2213/1313 Metering, billing
• CPC Class Codes: H04Q 2213/13174 Data transmission, file transfer
• CPC Class Codes: H04Q 2213/13176 Common channel signaling, CCS7
• CPC Class Codes: H04Q 2213/13191 Repeater
• CPC Class Codes: H04Q 2213/13204 Protocols
• CPC Class Codes: H04Q 2213/13209 ISDN
• CPC Class Codes: H04Q 2213/13213 Counting, timing circuits
• CPC Class Codes: H04Q 2213/13292 Time division multiplexing, TDM
• CPC Class Codes: H04Q 2213/13299 Bus
• CPC Class Codes: H04Q 2213/13305 Transistors, semiconductors in general
• CPC Class Codes: H04Q 2213/1332 Logic circuits
• CPC Class Codes: H04Q 2213/13322 : Integrated circuits
• CPC Class Codes: H04Q 2213/1334 : Configuration within the switch
• CPC Class Codes: H04Q 2213/13376 : Information service, downloading of information, 0800/0900 services
• CPC Class Codes: H04Q 2213/13381 : Pair-gain system, digital loop carriers
• CPC Class Codes: H04Q 3/5455 : Multi-processor, parallelism, distributed systems

Abstract

A multiple application switching platform includes a switch having a distributed open architecture and incorporating redundancy for enhanced fault tolerance. The switch includes at least one shelf having a midplane (1) containing message buses and TDM data buses (A and B). Shelves may be interconnected to form a group wherein various circuit cards are connected to each shelf midplane. The circuit cards (4, 5 and 6) perform call processing wherein each card within a group accessing a data bus is pre-assigned a unique set of time slots for each data bus within which that card may transmit onto that data bus. Each circuit card further includes an identification number that enables each card an opportunity to transmit onto a message bus (A and B). The circuit cards (4, 5 and 6) include line or trunk switch cards that function as an independent switch to interface line or trunks to a shelf midplane. Communications between lines or trunks connected to any group shelf is facilitated by switch cards communicating with each other via messages sent over the message buses (A and B).

Claims

1. A configurable multiple application telephone switch for connecting telephone calls between communication sources and communication destinations wherein said switch includes at least one group of one or more shelves wherein each said shelf includes a backplane for interconnecting said communication sources and said communication destinations, each said backplane having a plurality of backplane slots with each backplane slot associated with a unique identifier, each said group further comprising:

data bus means having a plurality of time slots for transferring telephone call information between said communication sources and said communication destinations;

message bus means for transferring messages that initiate communications between said communication sources and said communication destinations;

a plurality of switching means for interfacing each said communication source and each said communication destination to a corresponding shelf;

management means for selectively assigning various quantities of said time slots to each said switching means based on a desired ratio of time slots per communication sources and communication destinations interfaced by that switching means to control traffic concentration, wherein each said switching means includes;

message means for exchanging said messages that initiate communications between said communication sources and said communication destinations via said message bus means;

time slot selection means for selecting one of said assigned time slots for transferring said telephone call information onto said data bus means in response to said messages; and

data transfer means for placing said telephone call information onto said data bus means during said selected assigned time slots to facilitate transference of said telephone call information between said switching means interfacing said communication sources and said switching means interfacing said communication destinations in order to establish connections for said telephone calls;

wherein at least one of said plurality of switching means is disposed on each said shelf; and

administration means for receiving and maintaining configuration information including said time slot assignments from said management means and distributing said configuration information to each said switching means via said message bus means.

2. The switch of claim 1 wherein each said group further includes:

power bus means for distributing power signals within each said shelf within a group;

clock generation means for generating clock signals;

clock distribution means for distributing said clock signals from said clock generation means to each said shelf within a group; and

power supply means disposed on each said shelf within a group for generating said power signals and transferring said power signals to said power bus means.

3. The switch of claim 1 wherein each said group having a plurality of said shelves further includes:

expander means disposed on each said shelf within each said plural shelf group for interconnecting each said shelf within each said plural shelf group.

4. The switch of claim 6 further including:

data communications means for interfacing external systems to a corresponding group shelf, wherein said management means further includes data assignment means for selectively assigning a portion of said time slots to said data communications means, and said data communications means includes;

message exchange means for exchanging messages that initiate communications between said communication sources and said external systems via said message bus means of said corresponding group;

data time slot selection means for selecting one of said time slots assigned to said data communications means for transferring said telephone call information onto said data bus means of said corresponding group in response to said messages; and

data placement means for placing said telephone call information onto said data bus means of said corresponding group during said selected time slot assigned to said data communications means to facilitate transference of said telephone call information between said switching means interfacing said communication sources and said data communications means interfacing said external systems in order to establish a connection and process said telephone calls;

wherein said administration means of said corresponding group further includes configuration means for distributing said configuration information to said data communications means.

5. The switch of claim 1 further including:

a plurality of relay means associated with a group for selectively establishing connections for corresponding switching means of said associated group to process said telephone calls, and replacing said switching means of said associated group in response to said switching means incurring a failure.

6. The switch of claim 1 wherein said switch includes a plurality of groups and each said group includes at least one tandem means for interconnecting each said group.

7. The switch of claim 1 wherein said switch includes a plurality of groups and at least one tandem switch that interconnects each said group, wherein each said group includes at least one tandem means for connecting each said group to said at least one tandem switch.

8. The switch of claim 1 wherein:

each said switching means further includes message access means for enabling access to said message bus means, and data bus access means for enabling access to said data bus means; and

said administration means further includes said message access means for enabling access to said message bus means.

9. The switch of claim 8 wherein said data bus means includes at least one data bus with each data bus having at least one data bus portion including a plurality of said time slots for transferring said telephone call information, wherein said management means includes assignment means for selectively assigning said time slots from each said data bus portion to each said switching means to enable transmission of said telephone call information onto each said data bus portion once during each said time slot, and said data bus access means includes data bus interface means for enabling transmission onto each said data bus portion once during each said time slot based on said data bus portion assigned time slots.

10. The switch of claim 8 wherein said message bus means includes at least one message bus, and said message bus access means includes message interface means for enabling transmission of a message from each said shelf within a group in sequential order based on said identifiers to enable transmission of only one message onto each said message bus at any one time.

11. The switch of claim 1 wherein said data bus means includes time division multiplexed data buses, and said message bus means includes high level data link control buses.

12. The switch of claim 1 wherein each said group further includes power bus means for distributing power signals within each said shelf within a group, and each said switching means further includes:

an interface for interfacing said communication sources and said communication destinations;

processing means for controlling processing of said telephone calls, said interface and reception and transmission of said messages; and

power means for receiving power signals from said power bus means and converting said power bus signals to particular signals required by said switching means.

14. The switch of claim 1 wherein each said group further includes power bus means for distributing power signals within each said shelf within a group, and said administration means further includes:

an administration interface for interfacing external systems;

processing means for controlling said administration interface and reception and transmission of said messages;

storage means for maintaining call processing and billing information; and

power means for receiving power signals from said power bus means and converting said power signals to particular signals required by said administration means.

15. The switch of claim 4 wherein each said group further includes power bus means for distributing power signals within each said shelf within a group, and said data communications means further includes:

a first interface for interfacing an external host computer;

a second interface for interfacing external signaling systems;

processing means for controlling said first and second interfaces and reception and transmission of said messages; and

power means for receiving power signals from said power bus means and converting said power signals to particular signals required by said data communications means.

16. The switch of claim 2 wherein said power supply means includes an inverter for converting input power signals to particular power signals appropriate for distribution to said power bus means.

19. The switch of claim 1 wherein said configuration information further includes monitoring information, and said message bus means includes low speed serial buses for receiving said monitoring information and transferring said monitoring information to said administration means.

20. The switch of claim 8 wherein said data bus means includes at least one data line and an enable line, and said data bus access means includes:

a transmit indicator memory for storing information indicating said time slots assigned for transmitting said telephone call information onto each said data line;

a transmit indicator counter for sequentially addressing said transmit indicator memory during each said time slot;

a receive memory for storing said telephone call information retrieved from each said data line;

a receive memory counter for sequentially addressing said receive memory during each said time slot;

receive means for retrieving said telephone call information from said receive memory for transmission external of said data bus access means;

a transmit memory for storing said telephone call information to be transmitted onto each said data line;

a transmit memory counter for sequentially addressing said transmit memory during each said time slot indicated for transmission by said transmit indicator memory;

transmit means for receiving telephone call information for transmission onto each said data line, and placing said telephone call information into said transmit memory;

a transceiver for placing said telephone call information from each said data line into said receive memory when said transceiver is in a receive state, and placing said telephone call information from said transmit memory onto each said data line when said transceiver is in a transmit state, wherein said transceiver is biased to said receive and transmit states in response to said information within said transmit indicator memory; and

toggling means for controlling placement of said telephone call information received from said at least one data line in separate memory areas within said receive memory, and controlling placement of said telephone call information for transmission onto said at least one data line in separate memory areas within said transmit memory.

21. The switch of claim 8 wherein said message bus means includes at least one data line, a hold line, an enable line and a sync line, and said message access means includes:

a counter for cycling through said identifiers, wherein said counter is enabled by said hold line and reset by said sync line;

comparing means for comparing a count from said counter to one of said identifiers;

storage means for storing a request signal indicating that a message is available for transmission onto each said data line;

a receiver/transmitter for receiving a message from each said data line in response to said comparing means indicating said count does not equal said one identifier, and transmitting said available message onto each said data line when said comparing means indicates that said count equals said one identifier and said request signal indicates that said available message is loaded within said receiver/transmitter for transmission onto each said data line;

a data transceiver for retrieving said message from each said data line and placing said message in said receiver/transmitter when said data transceiver is in a receive state, and transmitting said available message from said receiver/transmitter onto each said data line when said data transceiver is in a transmit state wherein said data transceiver is biased to said receive and transmit states in response to said request signal and comparison results of said comparing means;

a hold transceiver for receiving signals from said hold line to enable said counter when said hold transceiver is in a receive state, and placing a hold signal onto said hold line to disable said counter when said hold transceiver is in a transmit state wherein said hold transceiver is biased to said receive and transmit states in response to said request signal and said comparison results of said comparing means; and

a driver for placing an enable signal onto said enable line when said receiver/transmitter transmits said available message onto each said data line.

24. The switch of claim 1 wherein said message bus means transfers said messages utilizing a High Level Datalink Control (HDLC) protocol.

25. The switch of claim 1 wherein said message bus means transfers said messages utilizing a TCP/IP protocol.

26. The switch of claim 1 further including:

common resource means for processing said telephone calls and generating said communication initiating messages in response to said call processing to enable communications between said communication sources and said communication destinations;

wherein said message bus means transfers said communication initiating messages among said switching means interfacing said communication sources, said switching means interfacing said communication destinations and said common resource means.

13. The switch of 12 wherein each said switching means further includes:

tone means for receiving and interpreting tones from said communication sources and said communication destinations, and converting information to said tones for transmission of said converted information to said communication sources and said communication destinations.

18. The switch of 2 wherein:

said power bus means includes two redundant power buses; and

said clock distribution means includes two redundant sets of clock distribution lines.

27. In a configurable multiple application telephone switch for connecting telephone calls between communication sources and communication destinations wherein said switch includes a data bus having at least one data line, an enable line and a plurality of time slots for transferring telephone call information between said communication sources and said communication destinations, and a plurality of call processing means for establishing connections between said communication sources and said communication destinations to process said telephone calls wherein said call processing means are assigned said plurality of time slots to enable transference of telephone call information onto said data bus, an apparatus for enabling transference of telephone call information onto said data bus during assigned time slots comprising:

a transmit indicator memory for storing information indicating said assigned time slots for transmitting said telephone call information onto each said data line;

a transmit indicator counter for sequentially addressing said transmit indicator memory during each said time slot;

a receive memory for storing said telephone call information retrieved from each said data line;

a receive memory counter for sequentially addressing said receive memory during each said time slot;

receive means for retrieving said telephone call information from said receive memory for transmission external of said apparatus;

a transmit memory for storing said telephone call information to be transmitted onto each said data line;

a transmit memory counter for sequentially addressing said transmit memory during each said assigned time slot indicated for transmission by said transmit indicator memory;

transmit means for receiving telephone call information for transmission onto each said data line and placing said telephone call information into said transmit memory;

a transceiver for placing said telephone call information from each said data line into said receive memory when said transceiver is in a receive state, and placing said telephone call information from said transmit memory onto each said data line when said transceiver is in a transmit state, wherein said transceiver is biased to said receive and transmit states in response to said information within said transmit indicator memory; and

toggling means for controlling placement of said telephone call information received from said at least one data line in separate memory areas within said receive memory, and controlling placement of said telephone call information for transmission onto said at least one data line in separate memory areas within said transmit memory.

28. In a configurable multiple application telephone switch for connecting telephone calls between communication sources and communication destinations wherein said switch includes a message bus having at least one data line, a hold line, an enable line and a sync line for transferring messages that initiate communications between said communication sources and said communication destinations, and a plurality of call processing means for establishing connections between said communication sources and said communication destinations wherein each said call processing means is associated with a unique identifier, an apparatus for enabling said call processing means to transfer messages onto said message bus in sequential order comprising:

a counter for cycling through said identifiers, wherein said counter is enabled by said hold line and reset by said sync line;

comparing means for comparing a count from said counter to one of said identifiers;

storage means for storing a request signal indicating that a message is available for transmission onto each said data line;

a receiver/transmitter for receiving a message from each said data line in response to said comparing means indicating said count does not equal said one identifier, and transmitting said available message onto each said data line when said comparing means indicates that said count equals said one identifier and said request signal indicates that said available message is loaded within said receiver/transmitter for transmission onto each said data line;

a data transceiver for retrieving said message from each said data line and placing said message in said receiver/transmitter when said data transceiver is in a receive state, and transmitting said available message from said receiver/transmitter onto each said data line when said data transceiver is in a transmit state wherein said data transceiver is biased to said receive and transmit states in response to said request signal and comparison results of said comparing means;

a hold transceiver for receiving signals from said hold line to enable said counter when said hold transceiver is in a receive state, and placing a hold signal onto said hold line to disable said counter when said hold transceiver is in a transmit state wherein said hold transceiver is biased to said receive and transmit states in response to said request signal and said comparison results of said comparing means; and

a driver for placing an enable signal onto said enable line when said receiver/transmitter transmits said available message onto each said data line.

29. In a configurable multiple application telephone switch for connecting telephone calls between communication sources and communication destinations wherein said switch includes at least one group having a plurality of shelves, wherein each said group within said switch includes clock means for generating and distributing clock signals to each said shelf within a group, wherein each said shelf includes a data bus having a plurality of time slots for transferring telephone call information between said communication sources and said communication destinations and a plurality of call processing means for establishing connections between said communication sources and said communication destinations, and wherein said data bus includes at least one data line and an enable line, an apparatus for transferring information between data buses of each said shelf within each said group having a plurality of said shelves via vertical buses comprising:

a data line transceiver for transferring said telephone call information from said vertical buses to each said data line when said data line transceiver is in a receive state, and transmitting said telephone call information from each said data line to said vertical buses when said data line transceiver is in a transmit state;

a receiver for receiving enable signals from said enable line enduring for half a cycle of said clock signals; and

enable extending means for receiving said half clock enable signals from said receiver and extending said enable signals to a full clock cycle to bias said data line transceiver to a transmit state for said full clock cycle.

30. In a configurable multiple application telephone switch for connecting telephone calls between communication sources and communication destinations wherein said switch includes at least one group having a plurality of shelves, wherein each said shelf includes a message bus for transferring messages that initiate communications between said communication sources and said communication destinations and a plurality of call processing means for establishing connections between said communication sources and said communication destinations wherein each said call processing means is associated with a unique identifier and said message bus includes at least one message data line, a message enable line, a hold line and a sync line, and wherein each said group within said switch includes clock means for generating and distributing clock signals to each said shelf within a group, a master counter for cycling through said identifiers wherein said master counter is enabled by said hold line and includes a terminal count output that indicates when said master counter reaches a predetermined final value and a driver for placing said terminal count output onto said sync line to indicate completion of a cycle through said identifiers by said master counter, an apparatus for transferring information between message buses of each said shelf within each said group having a plurality of said shelves via vertical buses comprising:

a message transceiver for transferring said messages from said vertical buses to each said message data line when said message transceiver is in a receive state, and transferring said messages from each said message data line to said vertical buses when said message transceiver is in a transmit state;

a message receiver for receiving message enable signals from said message enable line enduring for half a cycle of said clock signals; and

message enable extending means for receiving said half clock message enable signals from said message receiver and extending said message enable signals to a full clock cycle to bias said message transceiver to a transmit state for said full clock cycle.

31. In a configurable multiple application telephone switch including at least one group having one or more shelves wherein each said shelf includes a backplane having a plurality of backplane slots with each backplane slot associated with a unique identifier, each said group further including data bus means having a plurality of time slots for transferring telephone call information, message bus means for transferring messages and a plurality of switching means for handling telephone calls, a method of connecting said telephone calls between communication sources and communication destinations comprising the steps of:

(a) interfacing each said communication source and each said communication destination to a corresponding shelf via said plurality of switching means;

(b) selectively assigning various quantities of said time slots to each said switching means based on a desired ratio of time slots per communication sources and communication destinations interfaced by that switching means to control traffic concentration, and distributing configuration information including said time slot assignments to each said switching means via said message bus means;

(c) exchanging messages that initiate communications between said communication sources and said communication destinations via said message bus means; and

(d) transferring said telephone call information between said switching means interfacing said communication sources and said switching means interfacing said communication destinations in response to said messages, wherein said switching means interfacing said communication sources and said switching means interfacing said communication destinations each select a time slot from among said quantity of time slots assigned to that switching means such that said plurality of switching means transfers said telephone call information during said selected time slots via said data bus means to establish connections for said telephone calls.

17. The switch of claim 33 wherein each said group further includes power bus means for distributing power signals within each said shelf within a group and said expander means further includes:

bus repeater means for transferring information between each said shelf within each said plural shelf group; and

power means for receiving power signals from said power bus means and converting said power signals to particular signals required by said expander means.

22. The switch of claim 17 wherein each said group further includes clock means for generating and distributing clock signals to each said shelf within a group, said data bus means is disposed on each said shelf and includes at least one data line and an enable line, and said expander means transfers information between each said shelf within each said plural shelf group via vertical buses, said bus repeater means including:

a data line transceiver for transferring said telephone call information from said vertical buses to each said data line when said data line transceiver is in a receive state, and transmitting said telephone call information from each said data line to said vertical buses when said data line transceiver is in a transmit state;

a receiver for receiving enable signals from said enable line enduring for half a cycle of said clock signals; and

enable extending means for receiving said half clock enable signals from said receiver and extending said enable signals to a full clock cycle to bias said data transceiver to a transmit state for said full clock cycle.

23. The switch of claim 17 wherein said message bus means is disposed on each said shelf and includes at least one message data line, a message enable line, a hold line and a sync line, wherein said expander means transfers information between each said shelf within each said plural shelf group via vertical buses, and wherein each said group further includes clock means for generating and distributing clock signals to each said shelf within a group, a master counter for cycling through said identifiers wherein said master counter is enabled by said hold line and includes a terminal count output that indicates when said master counter reaches a predetermined final value and a driver for placing said terminal count output onto said sync line to indicate completion of a cycle through said identifiers by said master counter, said bus repeater means including:

a message transceiver for transferring said messages from said vertical buses to each said message data line when said message transceiver is in a receive state, and transferring said messages from each said message data line to said vertical buses when said message transceiver is in a transmit state;

a message receiver for receiving message enable signals from said message enable line enduring for half a cycle of said clock signals; and

message enable extending means for receiving said half clock message enable signals from said message receiver and extending said message enable signals to a full clock cycle to bias said message transceiver to a transmit state for said full clock cycle.

32. The method of claim 31 wherein said switch further includes data communications means for interfacing external systems, and step (a) further includes:

(a.1) interfacing said external systems to a corresponding shelf via said data communications means;

step (b) further includes;

(b.1) selectively assigning a portion of said time slots to said data communications means, and distributing said configuration information to said data communications means;

step (c) further includes;

(c.1) exchanging messages that initiate communications between said communication sources and said external systems; and

step (d) further includes;

(d.1) transferring said telephone call information between said switching means interfacing said communication sources and said data communications means in response to said messages, wherein said switching means interfacing said communication sources and said data communications means each select an assigned time slot and transfer said telephone call information during said selected assigned time slots via said data bus means to establish connections for said telephone calls.

33. The method of claim 31 wherein step (a) further includes:

(a.1) selectively establishing connections for said plurality of switching means to handle said telephone calls; and

said method further including the step of;

(e) selectively replacing said switching means in response to said switching means incurring a failure.

34. The method of claim 31 wherein said switch includes a plurality of groups, and step (a) further includes:

(a.1) interconnecting each said group to increase capacity of said switch.

35. The method of claim 31 wherein said switch includes a plurality of groups and at least one tandem switch, and step (a) further includes:

(a.1) interconnecting each said group to increase capacity of said switch by connecting each said group to said at least one tandem switch.

36. The method of claim 31 wherein said data bus means includes at least one data bus with each data bus having at least one data bus portion including a plurality of said time slots for transferring said telephone call information, and step (b) further includes:

(b.1) selectively assigning said time slots from each said data bus portion to each said switching means to enable transmission of said telephone call information onto each said data bus portion once during each said time slot; and

step (d) further includes;

(d.1) transmitting said telephone call information onto each said data bus portion once during each said time slot based on said data bus portion assigned time slots.

37. The method of claim 31 wherein said message bus means includes at least one message bus, and step (c) further includes:

(c.1) transmitting a message onto each said message bus from each said shelf within a group in sequential order based on said identifiers to enable transmission of only one message onto each said message bus at any one time.

38. The method of claim 31 wherein said data bus means includes time division multiplexed data buses, and said message bus means includes high level data link control buses, and wherein step (c) further includes:

(c.1) exchanging said messages that initiate communications between said communication sources and said communication destinations via said high level data link control buses; and

step (d) further includes;

(d.1) transferring said telephone call information between said switching means interfacing said communication sources and said switching means interfacing said communication destinations via said time division multiplexed data buses.

39. The method of claim 31 wherein said data bus means is disposed on each said shelf, and said method further includes the step of:

(e) transferring information between said data bus means of each said shelf within each said group having a plurality of said shelves such that each data bus means within a group includes the same information.

40. The method of claim 31 wherein said message bus means is disposed on each said shelf, and said method further includes the step of:

(e) transferring information between said message bus means of each said shelf within each said group having a plurality of said shelves such that each message bus means within a group includes the same information.

41. The method of claim 31 wherein said configuration information includes monitoring information, said message bus means includes low speed serial buses, and step (c) further includes:

(c.1) monitoring each said group via said monitoring information placed on each said low speed serial bus.

42. The method of claim 37 wherein step (c.1) further includes:

(c.1.1) incrementing a count corresponding to said identifiers wherein said count cycles through said identifiers to enable each said shelf within a group to transmit a message onto said message bus means;

(c.1.2) comparing said count to one of said identifiers;

(c.1.3) enabling reception of a message from said message bus means when said count does not equal said one identifier;

(c.1.4) enabling transmission of an available message onto said message bus means when said count equals said one identifier; and

(c.1.5) preventing said incrementing of said count during transmission of said available message.

43. The method of claim 36 wherein step (d.1) further includes:

(d.1.1) identifying said time slots associated with a particular data bus portion assigned for transmission onto said particular data bus portion;

(d.1.2) enabling reception of said telephone call information from said particular data bus portion during said time slots associated with said particular data bus portion; and

(d.1.3) enabling transmission of said telephone call information onto said particular data bus portion during said identified time slots that are assigned for transmission onto said particular data bus portion.

44. The method of claim 31 wherein step (c) further includes:

(c.1) exchanging said messages by utilizing a High Level Datalink Control (HDLC) protocol.

45. The method of claim 31 wherein step (c) further includes:

(c.1) exchanging said messages by utilizing a TCP/IP protocol.

46. The method of claim 31 wherein said switch further includes common resources for processing said telephone calls, and step (c) includes:

(c.1) processing said telephone calls via said common resources and generating said communication initiating messages in response to said call processing to enable communications between said communication sources and said communication destinations; and

(c.2) exchanging said communication initiating messages among said switching means interfacing said communication sources, said switching means interfacing said communication destinations and said common resources.

47. In a configurable multiple application telephone switch including data bus means for transferring telephone call information, message bus means for transferring messages and a plurality of switching means for handling telephone calls, wherein each said switching means is associated with a unique identifier, a method of connecting telephone calls between communication sources and communication destinations comprising the steps of:

(a) interfacing said communication sources and said communication destinations via said plurality of switching means to handle said telephone calls;

(b) exchanging messages that initiate communications between said communication sources and said communication destinations via said message bus means, wherein said switch further includes common resources for processing said telephone calls, and step (b) further includes;

(b.1) processing said telephone calls via said common resources and generating said communication initiating messages in response to said call processing to enable communications between said communication sources and said communication destinations; and

(b.2) exchanging said communication initiating messages among said switching means interfacing said communication sources, said switching means interfacing said communication destinations and said common resources; and

(c) transferring said telephone call information between said switching means interfacing said communication sources and said switching means interfacing said communication destinations via said data bus means, wherein said switching means interfacing said communication sources and said switching means interfacing said communication destinations each select a transmit time from among a various quantity of unique transmit times selectively assigned to that switching means such that said each switching means transfers said telephone call information onto said data bus means during said selected transmit time and receives information during other times in order to establish connections for telephone calls in response to receiving said messages.

48. In a configurable multiple application telephone switch including data bus means for transferring telephone call information, message bus means for transferring messages and a plurality of switching means for handling telephone calls, wherein each said switching means is associated with a unique identifier, a method of connecting telephone calls between communication sources and communication destinations comprising the steps of:

(a) interfacing said communication sources and said communication destinations via said plurality of switching means to handle said telephone calls;

(b) exchanging messages that initiate communications between said communication sources and said communication destinations via said message bus means, wherein step (b) further includes;

(b.1) exchanging said messages that initiate communications between said communication sources and said communication destinations wherein each said switching means transfers a message onto said message bus means in sequential order based on said associated identifier and receives messages from said message bus means when not transferring said message onto said message bus means; and

(c) transferring said telephone call information between said switching means interfacing said communication sources and said switching means interfacing said communication destinations via said data bus means, wherein said switching means interfacing said communication sources and said switching means interfacing said communication destinations each select a transmit time from among a various quantity of unique transmit times selectively assigned to that switching means such that said each switching means transfers said telephone call information onto said data bus means during said selected transmit time and receives information during other times in order to establish connections for telephone calls in response to receiving said messages.