WO2002033864A1 - Multi-interface telephony test system using separate interface cards - Google Patents

Multi-interface telephony test system using separate interface cards Download PDF

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Publication number
WO2002033864A1
WO2002033864A1 PCT/US2001/032533 US0132533W WO0233864A1 WO 2002033864 A1 WO2002033864 A1 WO 2002033864A1 US 0132533 W US0132533 W US 0132533W WO 0233864 A1 WO0233864 A1 WO 0233864A1
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WO
WIPO (PCT)
Prior art keywords
module
interface
physical interface
audio
dsp
Prior art date
Application number
PCT/US2001/032533
Other languages
French (fr)
Inventor
John Doyle
Lawrence Smith
Original Assignee
Empirix Inc.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Empirix Inc. filed Critical Empirix Inc.
Priority to AU2002224433A priority Critical patent/AU2002224433A1/en
Publication of WO2002033864A1 publication Critical patent/WO2002033864A1/en

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Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04Q—SELECTING
    • H04Q3/00—Selecting arrangements
    • H04Q3/64—Distributing or queueing
    • H04Q3/68—Grouping or interlacing selector groups or stages
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04Q—SELECTING
    • H04Q2213/00—Indexing scheme relating to selecting arrangements in general and for multiplex systems
    • H04Q2213/13003—Constructional details of switching devices
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04Q—SELECTING
    • H04Q2213/00—Indexing scheme relating to selecting arrangements in general and for multiplex systems
    • H04Q2213/13031—Pulse code modulation, PCM
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04Q—SELECTING
    • H04Q2213/00—Indexing scheme relating to selecting arrangements in general and for multiplex systems
    • H04Q2213/13106—Microprocessor, CPU
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04Q—SELECTING
    • H04Q2213/00—Indexing scheme relating to selecting arrangements in general and for multiplex systems
    • H04Q2213/13107—Control equipment for a part of the connection, distributed control, co-processing
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04Q—SELECTING
    • H04Q2213/00—Indexing scheme relating to selecting arrangements in general and for multiplex systems
    • H04Q2213/13109—Initializing, personal profile
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04Q—SELECTING
    • H04Q2213/00—Indexing scheme relating to selecting arrangements in general and for multiplex systems
    • H04Q2213/13176—Common channel signaling, CCS7
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04Q—SELECTING
    • H04Q2213/00—Indexing scheme relating to selecting arrangements in general and for multiplex systems
    • H04Q2213/13292—Time division multiplexing, TDM
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04Q—SELECTING
    • H04Q2213/00—Indexing scheme relating to selecting arrangements in general and for multiplex systems
    • H04Q2213/13299—Bus
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04Q—SELECTING
    • H04Q2213/00—Indexing scheme relating to selecting arrangements in general and for multiplex systems
    • H04Q2213/1334—Configuration within the switch
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04Q—SELECTING
    • H04Q2213/00—Indexing scheme relating to selecting arrangements in general and for multiplex systems
    • H04Q2213/13341—Connections within the switch
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04Q—SELECTING
    • H04Q2213/00—Indexing scheme relating to selecting arrangements in general and for multiplex systems
    • H04Q2213/13396—Signaling in general, in-band signalling

Definitions

  • TI and El are interfaces for telecommunications channels.
  • TI comprises the North
  • TI supports data rates of 1.554 Mbits per second.
  • a TI line comprises 24 individual channels, each supporting 64Kbits per second.
  • Each channel of a TI line can be configured to carry either voice or data traffic.
  • El is similar to TI, except that El is the European format for digital transmission. El supports data rates at 2.048 Mbits per second. An El line comprises 32 channels at 64K bits per second each. Similar to TI, El can be configured to carry either voice or data traffic.
  • Alternatives to the present invention include duplicating the voice resources on both TI and El Physical interface boards. This would result in using twice the number of boards or twice the number of systems to get the same number of channels. This method would prove to be costly to implement.
  • Another alternative would involve modifying the system to use the physical interfaces without allocating full voice channel DSP resources. This method would provide a less flexible and capable test system.
  • a further alternative would be to design a new board with a programmable part to accomplish the Tl/El interface swapping. This method would be proprietary, slow, and expensive.
  • Yet another alternative would be to physically swap boards in and out of the test system when needed. This method would also be expensive as well as prone to error, and would require manual labor by the customer.
  • Still another alternative involves utilizing an external switch simulator that can convert TI to El and vice versa. This method is expensive and impractical. In view of the above, it would be desirable to provide a multi-interface telephony test system using separate interface cards.
  • the present invention also requires the ability to run protocols normally associated with TI physical interfaces on a card with only El physical interfaces. It was further required that a method for changing the configuration from TI to El and from El to TI be provided as well. Additionally, a method for configuring the system to look like a single set of contiguous
  • TI or El channels was developed, when in fact the hardware resources are not contiguous.
  • PCM Code Modulated
  • Fig. 1 is a block diagram showing the switching configuration of an interface board and a resource board according to the present invention
  • Fig. 2 is a diagram of a rear view of a chassis containing both El and TI modules.
  • the resource card in the telecommunication test system has four physical and electrical interfaces for TI or El (for a total of 96 voice channels or 120 voice channels).
  • the resource card has only enough voice resources to run two physical interfaces (for a total of 48 or 60 simultaneous voice channels). Accordingly, two of the physical interfaces are disabled and left idle.
  • a first interface board such as a TI interface board is shown.
  • the interface board includes an h.lOO switch block 100, a local switch block 1 10, an HDLC 120, a Digital Signal Processor (DSP) 130 and four Framers 140, 150, 160 and 170.
  • the data from Framer 140 (span 0) is fed into local switch block 110.
  • the data leaves local switch block 1 10 and is provided to DSP 130.
  • the output of DSP 130 is connected to another port of local switch block 1 10, which provides the signal back to Framer 140.
  • Framer 150 is similar to Framer 140 and signals from Framer 150 follow a similar path.
  • the signal leaves Framer 150 and is received by local switch block 110.
  • the signal exits local switch block 110 and is directed to DSP 130. From DSP 130 the signal travels back to local switch block 110 and from their back to Framer 140.
  • H.lOO bus 30 Beginning with the lines coming from the Framer span 2 160 and Framer span 3 170 of the Interface board 10, these lines are routed to the H.lOO bus 30 through programmable switches labeled local switch block 110 and H.lOO switch block 100. From the h.lOO bus 30, at the Resource board 20, the lines are routed through programmable switches H.l OO switch block 200 and local switch block 210 to DSP (60) 230 of the Resource board 20. From DSP (60) 230 of the Resource board 20, the lines are routed back through local switch block 210 and h.lOO switch block 200 to the H.lOO bus 30. From the H.
  • the lines are routed through the H.lOO switch block 100 and the local switch block 1 10 of the interface board 10 and back to the Framer span 2 160 and Framer span 3 170. Accordingly, the DSP (60) 230 of the Resource board 20 is utilized by the interfaces 160 and 170 of the Interface board 10, thereby allowing for all four of the physical interfaces of the interface board to be utilized.
  • the present invention also required the ability to run protocols normally associated with TI physical interfaces on a card with only El physical interfaces.
  • the physical interfaces (Framers 240, 250, 260, and 270) are independent of the DSP resources (DSP 230) used to implement the protocol on the interfaces; this invention took advantage of this fact and ran TI protocols on DSP 230.
  • DSP 230 DSP resources
  • the software that initializes this application reads in the current switch configuration from a data file.
  • This data file tells the software to either treat the system as a TI system where the TI interfaces will be used along with sharing the DSP from the El boards or to treat the system as a El system where the El interfaces will be used along with sharing the DSP from the TI board.
  • a simple GUI application was created for the user to choose which configuration file to use.
  • a method for configuring the system to look like a single set of contiguous TI or El channels was developed, when in fact the hardware resources were not contiguous. This was done in software by presenting to the user a single set of either TI or El test ports. This is important so the user of the system does not have to worry weather a given test port is active or not. Only active test ports are shown.
  • PCM Pulse Code Modulate
  • the audio enabled resource board is able to receive either a-law encoded streams or Mu-law encodes streams but not both at once.
  • Software was written to dynamically switch the audio board from Mu-law to a-law and vice versa. The software configures the audio board to be enabled for the correct encoding when the user switches from one configuration to the other.
  • the present invention also permits the system to be cabled as TI and El at the same time. While the use of El or TI interfaces was described the present invention could also be used with other interfaces including, but not limited to, T3 and E3.
  • a computer usable medium can include a readable memory device, such as a hard drive device, a CD-ROM, a DVD-ROM, or a computer diskette, having computer readable program code segments stored thereon.
  • the computer readable medium can also include a communications link, either optical, wired, or wireless, having program code segments carried thereon as digital or analog signals.

Abstract

The present invention provides a method to configure the hardware and software resources in a system to utilize two physical interface boards (10, 20) such that their aggregate units of voice processing DSP resources (130, 230) can be applied to either all of a T1 board's physical interface. This allows a single telecommunications system to run as either T1 or E1 with no additional hardware required.

Description

TITLE OF THE INVENTION Multi-Interface Telephony Test System Using Separate Interface Cards
BACKGROUND OF THE INVENTION TI and El are interfaces for telecommunications channels. TI comprises the North
American format for digital transmission of data. TI supports data rates of 1.554 Mbits per second. A TI line comprises 24 individual channels, each supporting 64Kbits per second. Each channel of a TI line can be configured to carry either voice or data traffic.
El is similar to TI, except that El is the European format for digital transmission. El supports data rates at 2.048 Mbits per second. An El line comprises 32 channels at 64K bits per second each. Similar to TI, El can be configured to carry either voice or data traffic.
Prior to the present invention there has not been a telecommunication test system capable of running both TI and El interfaces with a single set of voice channel resource cards. There are Tl/El switchable test systems, however these systems included cards which had switchable framers and separate DSP resource cards. Previously, it was necessary to utilize a full set of TI resource cards for testing TI interfaces and a full set of El resource cards for testing El interfaces, all in a single system. One of the reasons for this is that TI and El have different electrical interfaces so providing a solution would require a hardware based enhancement as the capability is not software programmable.
Alternatives to the present invention include duplicating the voice resources on both TI and El Physical interface boards. This would result in using twice the number of boards or twice the number of systems to get the same number of channels. This method would prove to be costly to implement. Another alternative would involve modifying the system to use the physical interfaces without allocating full voice channel DSP resources. This method would provide a less flexible and capable test system. A further alternative would be to design a new board with a programmable part to accomplish the Tl/El interface swapping. This method would be proprietary, slow, and expensive. Yet another alternative would be to physically swap boards in and out of the test system when needed. This method would also be expensive as well as prone to error, and would require manual labor by the customer. Still another alternative involves utilizing an external switch simulator that can convert TI to El and vice versa. This method is expensive and impractical. In view of the above, it would be desirable to provide a multi-interface telephony test system using separate interface cards.
SUMMARY OF THE INVENTION With the foregoing background in mind, it is an object of the present invention to configure the hardware and software resources in a system to utilize two physical interface boards in pairs such that their aggregate units of voice processing DSP resources can be applied to either all of a TI board's physical interfaces or all of an El board's physical interfaces. This allows a single telecommunications system to run as either TI or El with no additional hardware required.
The present invention also requires the ability to run protocols normally associated with TI physical interfaces on a card with only El physical interfaces. It was further required that a method for changing the configuration from TI to El and from El to TI be provided as well. Additionally, a method for configuring the system to look like a single set of contiguous
TI or El channels was developed, when in fact the hardware resources are not contiguous.
It was also desirable to provide a method for monitoring audio by switching the Pulse
Code Modulated (PCM) audio streams from/to an audio enabled resource board and switching between listening to Mu-law encoded audio for TI and A-law encoded audio for El. The present invention also permits the system to be cabled as TI and El at the same time.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be better understood by reference to the following more detailed description and accompanying drawings in which:
Fig. 1 is a block diagram showing the switching configuration of an interface board and a resource board according to the present invention; and Fig. 2 is a diagram of a rear view of a chassis containing both El and TI modules. DETAILED DESCRIPTION
In a particular embodiment, the resource card in the telecommunication test system has four physical and electrical interfaces for TI or El (for a total of 96 voice channels or 120 voice channels). However, the resource card has only enough voice resources to run two physical interfaces (for a total of 48 or 60 simultaneous voice channels). Accordingly, two of the physical interfaces are disabled and left idle.
In order to provide a multi-interface telephony test system it was necessary to perform several modifications to an existing system. In particular, the DSP resources from one card had to be shared with another card.
Referring now to Fig. 1, a diagram showing the configuration necessary to accomplish part of the present invention is shown. A first interface board, such as a TI interface board is shown. The interface board includes an h.lOO switch block 100, a local switch block 1 10, an HDLC 120, a Digital Signal Processor (DSP) 130 and four Framers 140, 150, 160 and 170. The data from Framer 140 (span 0) is fed into local switch block 110. The data leaves local switch block 1 10 and is provided to DSP 130. The output of DSP 130 is connected to another port of local switch block 1 10, which provides the signal back to Framer 140.
Framer 150 is similar to Framer 140 and signals from Framer 150 follow a similar path. The signal leaves Framer 150 and is received by local switch block 110. The signal exits local switch block 110 and is directed to DSP 130. From DSP 130 the signal travels back to local switch block 110 and from their back to Framer 140.
While prior to the presently disclosed invention framer 160 and 170 would be left idle, now they can be used. The signal exiting framer 160 goes to local switch block 110 and from there to H.lOO switch block 100.
Beginning with the lines coming from the Framer span 2 160 and Framer span 3 170 of the Interface board 10, these lines are routed to the H.lOO bus 30 through programmable switches labeled local switch block 110 and H.lOO switch block 100. From the h.lOO bus 30, at the Resource board 20, the lines are routed through programmable switches H.l OO switch block 200 and local switch block 210 to DSP (60) 230 of the Resource board 20. From DSP (60) 230 of the Resource board 20, the lines are routed back through local switch block 210 and h.lOO switch block 200 to the H.lOO bus 30. From the H. lOO bus 30, the lines are routed through the H.lOO switch block 100 and the local switch block 1 10 of the interface board 10 and back to the Framer span 2 160 and Framer span 3 170. Accordingly, the DSP (60) 230 of the Resource board 20 is utilized by the interfaces 160 and 170 of the Interface board 10, thereby allowing for all four of the physical interfaces of the interface board to be utilized.
The present invention also required the ability to run protocols normally associated with TI physical interfaces on a card with only El physical interfaces. Referring to Fig 1, the physical interfaces (Framers 240, 250, 260, and 270) are independent of the DSP resources (DSP 230) used to implement the protocol on the interfaces; this invention took advantage of this fact and ran TI protocols on DSP 230. It was further required that a method for changing the configuration from TI to El and from El to TI be provided. Logically this is done by switching the roles of the Interface Board (10) and the Resource Board (20) in Figure 1. The software that initializes this application reads in the current switch configuration from a data file. This data file tells the software to either treat the system as a TI system where the TI interfaces will be used along with sharing the DSP from the El boards or to treat the system as a El system where the El interfaces will be used along with sharing the DSP from the TI board. A simple GUI application was created for the user to choose which configuration file to use. Additionally, a method for configuring the system to look like a single set of contiguous TI or El channels was developed, when in fact the hardware resources were not contiguous. This was done in software by presenting to the user a single set of either TI or El test ports. This is important so the user of the system does not have to worry weather a given test port is active or not. Only active test ports are shown.
It was also desirable to provide a method for monitoring audio by switching the Pulse Code Modulate (PCM) audio streams from/to an audio enabled resource board and switching between listening to Mu-law encoded audio and A-law encoded audio (because TI audio is usually Mu-law encoded and El audio is usually a-law encoded). The audio enabled resource board is able to receive either a-law encoded streams or Mu-law encodes streams but not both at once. Software was written to dynamically switch the audio board from Mu-law to a-law and vice versa. The software configures the audio board to be enabled for the correct encoding when the user switches from one configuration to the other.
The present invention also permits the system to be cabled as TI and El at the same time. While the use of El or TI interfaces was described the present invention could also be used with other interfaces including, but not limited to, T3 and E3.
Having described preferred embodiments of the invention it will now become apparent to those of ordinary skill in the art that other embodiments incorporating these concepts may be used. Additionally, the software included as part of the invention may be embodied in a computer program product that includes a computer useable medium. For example, such a computer usable medium can include a readable memory device, such as a hard drive device, a CD-ROM, a DVD-ROM, or a computer diskette, having computer readable program code segments stored thereon. The computer readable medium can also include a communications link, either optical, wired, or wireless, having program code segments carried thereon as digital or analog signals. Accordingly, it is submitted that that the invention should not be limited to the described embodiments but rather should be limited only by the spirit and scope of the appended claims.

Claims

CLAIMSWhat is claimed is:
1. A method of providing a multiple interface system comprising the steps of: providing a first module having a first physical interface; providing a second module having a second physical interface, said second physical interface being different from said first physical interface; and sharing a resource from said second module with said first module.
2. The method of claim 1 wherein said first physical interface and said second physical interface are selected from the group consisting of TI, El, T3 and E3.
3. The method of claim 1 wherein said resource comprises a digital signal processor (DSP).
4. The method of claim 1 wherein said second module runs a protocol associated with said first module.
5. The method of claim 1 further comprising the step of providing a communications path between said first module and second module.
6. The method of claim 1 further comprising the step of changing a configuration of said system from one associated with said first physical interface to one associated with said second physical interface.
7. The method of claim 1 further comprising the step of making the interface channels appear contiguous.
8. The method of claim 1 wherein at least one of said first module and said second module comprise an audio enabled module.
9. The method of claim 8 wherein said first module and said second module utilize Pulse Code Modulated (PCM) audio streams.
10. The method of claim 9 wherein said PCM audio stream comprises an audio stream selected from the group comprising Mu-law encoded audio and A-law encoded audio.
PCT/US2001/032533 2000-10-18 2001-10-18 Multi-interface telephony test system using separate interface cards WO2002033864A1 (en)

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US24153700P 2000-10-18 2000-10-18
US60/241,537 2000-10-18

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US20020046302A1 (en) 2002-04-18
US7068756B2 (en) 2006-06-27
AU2002224433A1 (en) 2002-04-29

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