3.1 Introduction

3.2 PPX Configuration File

3.3 Defining the Switch Fabric

3.4 Switch Fabric Attributes

3.5 Defining the Telephony Bus

3.5.1 Reserving Bus Streams and Timeslots

3.6 Defining a Board

3.6.1 Defining a Board's Switch

Defining Switch Attributes

Specifying the Telephony Bus

Defining Local Resources

3.7 Specifying Switch Connections

3.8 A Sample PPX Configuration File

3.1 Introduction

The Point-to-Point Switching configuration file specifies the switch configuration for the Point-to-Point Switching service. The Point-to-Point Switching configuration file defines:

• Each board in the system

• The telephony buses connected to each board

• The local inputs and outputs for each board

• Any nailed up switch connections in the system

The Point-to-Point Switching service is shipped with a template configuration file (ppx_tmpl.cfg) that contains examples for the various NMS board types. Copy this template to the default configuration file (ppx.cfg) and modify it to represent your system. Or, modify the file, give the file a unique name, and specify the name at startup using the -f option.

The Point-to-Point Switching service reads the Point-to-Point Switching configuration file into an internal switch connection database. When switch connections are requested, the Point-to-Point Switching service accesses the connection database to determine how to make the desired connection.

Note: The server will not run if it cannot locate a configuration file.

The example in Figure 13 shows:

1. An application requesting a connection between a DSP resource on an AG 4000 board and a line interface on an AG Quad T board.

2. The Point-to-Point Switching service accessing the connection database to determine how a connection can be made (for example, both boards are connected to the H.100 bus).

3. The Point-to-Point Switching service sending the appropriate switch commands to the boards to make the connections.
   
   
   Figure 13. Point-to-Point Switching Configuration File

3.2 PPX Configuration File

The active region of the Point-to-Point Switching configuration file begins with the string [PPX] on a line by itself and ends at the end of the file or at another word or phrase in square brackets on a line by itself. Any text outside that region is ignored by the Point-to-Point Switching service.

White space, such as indentation and space around an equals sign, is ignored but is useful for clarity. Case is ignored. The pound sign (#) and semicolon (;) are comment delimiters. The Point-to-Point Switching service ignores any text that follows a comment delimiter character on the same line.

In the Point-to-Point Switching configuration file, the switch fabric defines the topology of boards that are connected by telephony buses. Each computer chassis contains one switch fabric.

3.3 Defining the Switch Fabric

A switch fabric definition begins with a Fabric statement and ends with an End Fabric statement. All statements appearing between these two keywords define the switch fabric for the system.

A switch fabric definition has four basic components:

• General attribute section

• Defines general default attributes for the switching fabric.

Bus definition section

Defines the telephony buses in the system.

Switch configuration

Defines the configuration of each board in the system.

Switch connections

Specified in the Point-to-Point Switching configuration file and are made during Point-to-Point Switching initialization.

The format of the Point-to-Point Switching configuration file is:

  [PPX]
  Fabric
   # fabric attribute(s)
   # bus definition(s)
   # switch definitions
   # switch connections
  End Fabric

All configuration information for the system must exist inside the Fabric statement.

Figure 14 provides an overview of the Point-to-Point Switching configuration file and its structure. The example system contains three boards. The Point-to-Point Switching configuration file has a bus definition section describing the bus connecting the boards. Each board also has a switch configuration section.

Figure 14. Point-to-Point Switching Configuration File

3.4 Switch Fabric Attributes

Specify the default silence pattern used by the PPX server with the switch fabric attribute:

   IdleCode = [MU_LAW | A_LAW]

This attribute must appear immediately following the configuration file keyword Fabric, but before any of the other configuration data, as the following example shows:

        [PPX]
        Fabric
                 IdleCode = MU_LAW
                 # bus definition(s)
                 # switch definitions
                 # switch connections
        End Fabric

If this attribute is not present within the file, the default value used is MU_LAW (0x7F).

The value of the IdleCode attribute is used as the default idle pattern for connections created with a NULL passed as the parameter pointer.

3.5 Defining the Telephony Bus

In the Point-to-Point Switching configuration file, each telephony bus (H.110 or H.100) in the switch fabric must be defined and assigned a name.

Note: CT Bus is an industry standard telephony bus, defined by the ECTF H.100 and H.110 specifications. CT Bus is an interoperable superset of MVIP-90, H-MVIP, and SCbus. Therefore, references to CT Bus are inclusive of H.110, H.100, MVIP-90, and H-MVIP.

A bus is defined with either a bus specification or a bus declaration statement:

  Bus name
   bus_specification | bus_declaration
  End Bus

A bus_specification has the following syntax:

bus:streams[(increment)]:timeslots[(increment)]

The following table describes how each element is used:

Element	Description
bus	CTBUS, for H.100 or H.110 bus.
streams	Stream assignment. Can be one stream (for example, CTBUS:0:0), multiple streams (for example, CTBUS:0,2,4:0), or a range of streams (for example, CTBUS:0..7:0).
timeslots	Timeslot assignment. Can be one timeslot (for example, CTBUS:0:0), multiple timeslots (for example, CTBUS:0:0,2,4), or a range of timeslots (for example, CTBUS:0:0..7).
increment	Specifies a value to increment (for example, CTBUS:0..4(2):0 specifies streams 0, 2, 4).

For example, a bus specification statement for the H.100 bus (8 streams at 2 mbps; 24 streams at 8 mbps) is:

   Bus my_H100_bus
    CTBUS:0..7:0..31
    CTBUS:8..31:0..127
   End Bus

A bus_declaration defines a bus as it relates to a previously defined bus and has the following syntax:

   Bus new_bus_name
    existing_bus_name ([bus_specification])
   End Bus

The brackets following the bus name can include a range of timeslots, indicating that the bus is a subset of another bus. For example:

   Bus my_2MBPS_bus
    Bus my_H100_bus (CTBUS:0..7:0..31)
   End Bus

There can only be one top-level bus definition. Specify a top-level bus with the following syntax:

  CTBUS:streams:timeslots

A bus can be defined as a sub-bus of the top-level bus to indicate how buses connect. In the following example, the bus streams clocked at 2 mbps are defined as a subset of the H.100 bus:

  [PPX]
  Fabric
   Bus my_H100_bus       # H.100 bus definition
    CTBUS:0..15:0..31      # streams clocked at 2 MHz, 32 timeslots 
    CTBUS:16..23:0..63      # streams clocked at 4 MHz, 64 timeslots
    CTBUS:24..31:0..127      # streams clocked at 8 MHz, 128 timeslots
   End Bus
   Bus my_2MBPS_bus       #
    Bus my_H100_bus (CTBUS:0..15:0..31    )
   End Bus
  End Fabric

3.5.1 Reserving Bus Streams and Timeslots

If there are specific streams and timeslots on the telephony bus that are used by another application, the streams and timeslots can be reserved by specifying a subset of timeslots in the bus definition. The reserved streams and timeslots are not available to the Point-to-Point Switching service.

For example, to reserve the first four streams on the CT bus, define a bus as:

  Bus my_CT_bus
   CTBUS:0..15:0..31
  End Bus
  Bus PPX_AVAILABLE
   Bus my_CT_bus (CTBUS:4..15:0..31)
  EndBus

Reference the bus, PPX_AVAILABLE, when defining the boards connected to the bus.

3.6 Defining a Board

Each board in the system that connects to a telephony bus must have a switch definition in the switch fabric. A section defining a particular board starts with a Switch n statement and ends with an End Switch statement.

  Fabric
   # bus definitions for the switch fabric
   Switch 0
    # switch 0 definition
   End Switch
   Switch 1
    # switch 1 definition
   End Switch
   # switch connections
  End Fabric

Statements inside a switch definition apply only to that particular board. Each board in the switch fabric must have a unique switch number assigned in the Point-to-Point Switching configuration file. These switch numbers must all be unique. The numbers are arbitrary identifiers and are unrelated to the physical board configuration.

The switch-specific section for each board includes the following statements:

• Switch attributes, which describe the switch and the switching driver:

     switch_attribute = value
  
  

• Telephony bus connection, which defines the bus connected to the switch on the board:

     bus name ([bus_specification])
  
  

• Inputs and outputs for the board, which defines local resources, such as line interfaces and DSP resources:

     Inputs
      bus_specification | bus_declaration
     End Inputs
  

3.6.1 Defining a Board's Switch

The switch-specific region for a board must include the switch attributes, telephony bus connection, and local inputs and outputs.

Defining Switch Attributes

The switch attributes are the:

• Switch type

• Switch driver name

• Device number of the board

• Initial switch state

The switch type is used by the Point-to-Point Switching service to determine the type of switch present on the board and is specified by:

   SwitchType = switch

Valid switch types include:

Switch Type	Description
FMIC	Flexible MVIP Interface Circuit providing a complete enhanced-MVIP-90 bus.
HMIC	H.100/MVIP Integrated Circuit, providing a complete interface to the CT Bus. Note: The HMIC designation is used here in a general sense; it actually represents a set of different chips that implements the HMIC design, for example, the Lucent T8100 chip being used on the AG 4000.

The switch driver name is specified by:

  DeviceName = switch_driver

The device number is specified by:

  DeviceNumber = board_number

The device number specified in the Point-to-Point Switching configuration file is the board number assigned to the board. Refer to the NMS OAM System User's Manual for more information on board numbers.

Note: If a board is not being booted by NMS OAM (for example, boards booted by legacy agmon), then the board number is the same as the number used during the software installation.

The initial switch state is specified by:

   SwitchState = [disabled | enabled]

The presence of this attribute is optional. If it is not present, it is set to ENABLED by default. Use of this attribute is relevant to the presence of the Hot Swap service within the system. This attribute designates switches on boards that are planned to be inserted into currently unpopulated CompactPCI slots.

The switch attributes for an AG Quad T board are shown in the following example of a Point-to-Point Switching configuration file:

  [PPX]
  Fabric
   Bus my_H100_bus        # bus definition
    CTBUS:0..31:0..127
   End Bus
   Switch 0        # assigned as switch 0
    SwitchType = HMIC       # the switch on the AG Quad is an HMIC
    DeviceName = "agsw"       # AG board device driver - agsw   
    DeviceNumber = 1       # the logical board number assigned
             through OAM
    # Bus declaration
    # Board inputs
    # Board outputs
   End Switch
  End Fabric

The valid switch drivers, switch type, and device number for each NMS board are shown in the following table:

NMS Board	Device Name	Switch Type	Determining DeviceNumber
AG Quad, AG Dual, Quad Connect, AG 2000,AG 4000, AG 4000C, CompactPCI AG Quad, CG 6000C, CX 2000/C	agsw	HMIC	Assigned by the board specification in the configuration file.
QX 2000/100-4L	qxsw	HMIC
QX 2000/80-4L	qxsw	FMIC
CX 2000C	cxsw	HMIC

Specifying the Telephony Bus

The telephony bus connected to the board is specified by a bus declaration statement:

  Bus name ([bus_specification])

The bus name must have been previously defined in the bus definition section of the switch fabric.

For example, the H.100 bus is defined once and assigned the name my_H100_bus. This identifier, my_H100_bus, is used in the switch definitions for all boards connected to the H.100 bus.

  [PPX]
  Fabric
   Bus my_H100_bus        # H.100 bus definition
    CTBUS:0..31:0..127
   End Bus
   Switch 0        # assigned as switch 0
    DeviceName = "agsw"       # AG board switch driver - agsw   
    DeviceNumber = 1       # the logical board number assigned
           # through OAM
    SwitchType = HMIC       # the switch on the AG Quad is an HMIC
    Bus my_H100_bus ( )       # AG Quad is connected to H.100 bus
    # Board inputs
    # Board outputs
   End Switch
  End Fabric

The brackets following the bus name can include a range of timeslots indicating that the board supports a subset of a defined bus.

In a mixed H.100 and MVIP-90 system (for example, a system with a QX 2000/100-4L and a QX 2000/80-4L) the bus definition includes all streams on the H.100 bus:

  Bus my_H100_in_MVIP_mode
   CTBUS:0..15:0..31      # streams clocked at 2 MHz, 32 timeslots 
   CTBUS:16..23:0..63      # streams clocked at 4 MHz, 64 timeslots
   CTBUS:24..31:0..127      # streams clocked at 8 MHz, 128 timeslots
  End Bus

A QX 2000/100-4L board can connect to all streams on the H.100 bus. In the switch definition for the QX 2000/100-4L board, the bus declaration is:

  Bus my_H100_bus ()

The QX 2000/80-4L is an MVIP-90 board and can only access the first 16 streams. The switch definition for the QX 2000/80-4L includes a subset of the H.100 bus:

  Bus my_H100_bus (CTBUS:0..15:0..31)

Defining Local Resources

Resources (for example, network interfaces, DSP resources) that are located on the local bus as inputs to the switch (for example, voice stream coming from the telephone network) are specified by:

  Inputs
   LOCAL:streams[(increment)]:timeslots
  End Inputs

Resources that are located on the local bus as outputs from the switch (for example, voice stream going out to the telephone network) are specified by:

  Outputs
   LOCAL:streams[(increment)]:timeslots
  End Outputs

Typically, local resources on a board are located on consecutive streams. By convention, inputs use even-numbered streams and outputs use odd-numbered streams.

For example, for an AG Quad T board using channel associated signaling, the local resources are:

AG Quad T	Local Resources
Trunk Voice Information	Trunk 1: Streams 0 (input) and 1 (output), timeslots 0..23 Trunk 2: Streams 4 (input) and 5 (output), timeslots 0..23 Trunk 3: Streams 8 (input) and 9 (output), timeslots 0..23 Trunk 4: Streams 12 (input) and 13 (output), timeslots 0..23
Trunk Signaling Information	Trunk 1: Streams 2 (input) and 3 (output), timeslots 0..23 Trunk 2: Streams 6 (input) and 7 (output), timeslots 0..23 Trunk 3: Streams10 (input) and 11 (output), timeslots 0..23 Trunk 4: Streams 14 (input) and 15 (output), timeslots 0..23
DSP Voice Information	Streams 16 (input) and 17 (output), timeslots 0..127
DSP Signaling Information	Streams 18 (input) and 19 (output), timeslots 0..127

In the Point-to-Point Switching configuration file for the AG Quad T board, these local resources are defined as:

  [PPX]
  Fabric
   Bus my_H100_bus        # H.100 bus definition
    CTBUS:0..31:0..127
   End Bus
   Switch 0        # assigned as switch 0
    DeviceName = "agsw"       # AG board device driver - agsw   
    DeviceNumber = 1       # the logical board number assigned
           # through OAM
    SwitchType = HMIC       # the switch on the AG Quad is an HMIC
    Bus my_H100_bus   ()     # AG Quad is connected to H.100 bus
    Inputs
     LOCAL:0..14(2):0..23      # trunk voice and signaling
     LOCAL:16..18(2):0..127      # DSP voice and signaling
    End Inputs
    Outputs
     LOCAL:1..15(2):0..23      # trunk voice and signaling
     LOCAL:17..19(2):0..127      # DSP voice and signaling
    End Outputs
   End Switch
  End Fabric

3.7 Specifying Switch Connections

Switch connections are specified in the Point-to-Point Switching configuration file beginning with a Connect statement and ending with an End Connect statement. The switch connections are of the form:

 switch_number:bus:stream:timeslot TO switch_number:bus:stream:timeslot [NAILED] mode

The switch_number is the number assigned for the board with the Switch n statement in the Point-to-Point Switching configuration file. The bus may be CTBUS or LOCAL. The stream and timeslot specify which stream and timeslot to connect.

NAILED specifies that the connections cannot be broken with Point-to-Point switching commands. The mode may be SIMPLEX, DUPLEX, or QUAD.

For example, to connect the AG 2000 line interfaces to the on-board DSP resources:

  [PPX]
  Fabric
   Bus_2MBPS        
    CTBUS:0..15:0..31
   End Bus
   Switch 0        # AG 2000 assigned as switch 0
    DeviceName = "agsw"       # AG board device driver - agsw   
    DeviceNumber = 1       # the logical board number assigned
             through OAM
    SwitchType = HMIC       # the switch on the AG 2000 is an HMIC
     Bus MVIP_90   ()     # connected to the CT bus clocked at                              2 mbps
    Inputs
     LOCAL:0..2(2):0..7      # trunk voice and signaling
     LOCAL:4..6(2):0..7      # DSP voice and signaling
    End Inputs
    Outputs
     LOCAL:1..3(2):0..7      # trunk voice and signaling
     LOCAL:5..7(2):0..7      # DSP voice and signaling
    End Outputs
   End Switch
   Connect
    0:LOCAL:0:0..7 TO 0:LOCAL:5:0..7 NAILED QUAD
   End Connect
  End Fabric

Switch connections must appear as the last statements in the switch fabric definition. Connections are made when the PPX server is started. These initial switch connections can be disconnected by any application using ppxDisconnect unless specified with the NAILED keyword.

3.8 A Sample PPX Configuration File

The following PPX configuration file defines a system with a CG board and two AG 4000s:

[PPX]
Fabric
IdleCode = MU_LAW # Default idle pattern [ MU_LAW | A_LAW ]

Bus H110 # H110 bus
CTBUS:0..15:0..31 # 2 mbps Clocking
CTBUS:16..23:0..63 # 4 mbps "
CTBUS:24..31:0..127 # 8 mbps "
End Bus

Switch 0 # CG6000C
SwitchType = HMIC
DeviceName = "agsw"
DeviceNumber = 0
Bus H110 ()
Inputs
LOCAL:0..14(2):0..23 # Trunk
LOCAL:16..18(2):0..127 # DSP
End Inputs
Outputs
LOCAL:1..15(2):0..23
LOCAL:17..19(2):0..127
End Outputs
End Switch

Switch 1 # AG4000C

SwitchType = HMIC
DeviceName = "agsw"
DeviceNumber = 1
Bus H110 ()
Inputs
LOCAL:0..14(2):0..23 # Trunk
LOCAL:16..18(2):0..127 # DSP
End Inputs
Outputs
LOCAL:1..15(2):0..23 # Trunk
LOCAL:17..19(2):0..127 # DSP
End Outputs
End Switch

Switch 2 # AG4000C

SwitchType = HMIC
DeviceName = "agsw"
DeviceNumber = 2
Bus H100 ()
Inputs
LOCAL:0..14(2):0..23 # Trunk
LOCAL:16..18(2):0..127 # DSP
End Inputs
Outputs
LOCAL:1..15(2):0..23 # Trunk
LOCAL:17..19(2):0..127 # DSP
End Outputs
End Switch

End Fabric