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Chapter 4

MVIP and the Switching Service

4.1 Introduction
4.2 The CT Access Switching Service Use of MVIP-95
4.2.1 Interfacing to MVIP-95 Drivers and to MVIP-90 Drivers
4.2.2 New Functions
4.3 MVIP-95 and MVIP-90 Switch Model Comparison
4.3.1 MVIP-90 and MVIP-95: Differences
4.4 MVIP-90 Command Equivalents

4.1 Introduction

This chapter will help you migrate from MVIP-90 to MVIP-95 and to the CT Access Switching service subject to these considerations:

This chapter also provides a list of MVIP-90 functions, their equivalents in MVIP-95, and in the CT Access Switching service.

Note: It is important that you read Chapters 2, 3, and 4 of the CT Access Developer's Reference Manual prior to reading this chapter. The developer's manual contains concepts and terms that are essential to understanding the CT Access terminology in this chapter.

4.2 The CT Access Switching Service Use of MVIP-95

The CT Access Switching service:

4.2.1 Interfacing to MVIP-95 Drivers and to MVIP-90 Drivers

The Switching service may be used to open switching devices in either MVIP-95 mode or MVIP-90 mode.

In MVIP-95 mode, the terminus arguments to the Switching service functions are interpreted as MVIP-95 bus/stream/timeslot values. MVIP-95 is the default mode.

If the underlying device driver is an MVIP-95 device driver, the switch can only be opened in the default mode (MVIP-95).

Since MVIP-95 device drivers can only be opened in MVIP-95 mode, it is highly recommended that all applications that may use MVIP-95 device drivers in the future, be written to use MVIP-95 mode even if the application is not currently using MVIP-95 device drivers.

If the underlying device driver is an MVIP-90 device driver and the SWI_MVIP90 constant is used as a parameter to swiOpenSwitch, the switch is opened as an MVIP-90 switch. The terminus streams and timeslots are interpreted as MVIP-90 streams and timeslots. The bus field of the terminus is ignored.

If the underlying device driver is an MVIP-90 device driver, and the switch was opened in MVIP-95 mode, the Switching service translates the MVIP-95 terminus parameters into the appropriate MVIP-90 streams and timeslots before passing the commands down to the MVIP-90 device driver.

4.2.2 New Functions

This section presents a description of the new functions available in the CT Access Switching service that do not exist in MVIP-90. Refer to the chart at the end of this chapter for the equivalent MVIP-95 command.

Function

 Description

swiConfigStreamSpeed

 Configures the speed of one or more streams of the H-MVIP bus.

swiGetBoardInfo

 Retrieves information about the board controlled by the MVIP device driver.

swiGetDriverInfo

 Retrieves general and vendor specific information about the device driver.

swiGetLocalTimeslotInfo

 Retrieves stream and timeslot specific characteristics of a local device.

swiGetStreamsBySpeed

 Identifies all H-MVIP streams operating at one specified speed.

swiMakeFramedConnection

 Connects inputs to outputs with identical throughput delay for all connections.




If you call any of these functions on an MVIP-90 driver, CTAERR_FUNCTION_NOT_AVAIL is returned.



Refer to the Switching service chapter in the CT Access Developer's Reference Manual for more information.






4.3	  MVIP-95 and MVIP-90 Switch Model Comparison





One of the primary reasons for the emergence of the MVIP-95 switch block model was the specification of H-MVIP.



H-MVIP is a hardware standard which defines a telephony bus compatible with the one defined in MVIP-90. H-MVIP includes additional serial data streams. The additional data streams break the MVIP-90 software switch block model. A new switch block model was created to accommodate the additional data streams. The new switch block model became part of the new MVIP-95 standard.






4.3.1	 MVIP-90 and MVIP-95:  Differences





MVIP-95 offers many advantages over MVIP-90 because it:




As illustrated in Figure 7, the MVIP-90 convention for numbering the bus signals was to number each bus signal with two numbers, one for the input side of the switch block and the other number for the output side of the switch block. For example, on the input side of the switch block, the bus signals DSo0 through DSo7 correspond to streams 0 through 7. On the output side of the switch block, the bus signals DSo0 through DSo7 correspond to streams 8 through 15. Local streams begin at 16.


 



Figure 7.	 The MVIP-90 Switch Block Model




As illustrated in Figure 8, this was simplified in MVIP-95 by using one number to number each bus signal, regardless of the side of the switch block. In MVIP-95, bus signals are numbered sequentially starting at 0. This allows for future expansion of the switch capacity without renumbering.


 



Figure 8.	 The MVIP-95 Switch Block Model




For example, in MVIP-95, the MVIP bus signal DSo0 (H-MVIP bus signal HDS0) is numbered 0 regardless of which side of the switch block is connected to the signal.



In MVIP-90, local devices are connected to streams 16 and higher. In MVIP-95, local devices are connected to a logical bus called a local bus. The streams they are connected to are numbered sequentially starting from 0 on the local bus. 



In MVIP-95, both MVIP streams and local streams are numbered sequentially starting from 0. Therefore, there is a need to explicitly specify the bus when referring to a switch block input or output. MVIP-95 defines a new data structure called a terminus that contains a bus specifier, a stream number, and a timeslot number to refer to a switch block input and output.


 



Figure 9 shows the mapping of MVIP-90 streams to MVIP-95 streams.


 



Figure 9.	 Mapping of MVIP-90 Streams to MVIP-95 Streams






4.4	 MVIP-90 Command Equivalents





This table provides a list of MVIP-90 functions, their equivalents in MVIP-95 and, in the CT Access Switching service.





 





 MVIP-90 Command



 MVIP-95 Command



 Switching Service Function




 CARRIER_STATUS



 MVIP95_CMD_QUERY_LOCAL_STREAM



 swiGetLocalStreamInfo




 CONFIG_CARRIER



 MVIP95_CMD_CONFIG_LOCAL_STREAM



 swiConfigLocalStream




 CONFIG_CHANNEL



 MVIP95_CMD_CONFIG_LOCAL_TIMESLOT



 swiConfigLocalTimeslot




 CONFIG_CLOCK



 MVIP95_CMD_CONFIG_8KREF_CLOCK
and
MVIP95_CMD_CONFIG_BOARD_CLOCK
and
MVIP95_CMD_CONFIG_SEC8K_CLOCK



 swiConfig8KRefClock
and
swiConfigBoardClock
and
swiConfigSec8KClock




 DUMP_SWITCH



 MVIP95_CMD_DUMP_SWITCH



 swiCallDriver




 QUERY_OUTPUT



 MVIP95_CMD_QUERY_OUTPUT



 swiGetOutputState




 QUERY_SWITCH_CAPS



 MVIP95_CMD_QUERY_SWITCH_CAPS



 swiGetSwitchCaps




 RESET_SWITCH



 MVIP95_CMD_RESET_SWITCH



 swiResetSwitch




 SAMPLE_INPUT



 MVIP95_CMD_SAMPLE_INPUT



 swiSampleInput




 SET_OUTPUT



 MVIP95_CMD_SET_OUTPUT



 swiDisableOutput
and
swiMakeConnection
and
swiSendPattern




 SET_VERIFY



 MVIP95_CMD_SET_VERIFY



 swiSetVerify




 START_MONITOR



 None*



 swiCallDriver




 START_SUPV



 None*



 swiCallDriver




 STOP_SUPV



 None*



 swiCallDriver
















 * There is no MVIP-95 command equivalent. If your board has an MVIP-90
driver, you can access the MVIP-90 command through swiCallDriver.










 





 MVIP-90 Command



 MVIP-95 Command



 Switching Service Function




 TRISTATE_SWITCH



 MVIP95_CMD_SET_IMPEDANCE



 swiDisableSwitch
and
swiEnableSwitch




 WAIT_ALARM



 None*



 swiCallDriver




 WAIT_SUPV



 None*



 swiCallDriver




 None



 MVIP95_CMD_CONFIG_STREAM_SPEED



 swiConfigStreamSpeed**




 None



 MVIP95_CMD_QUERY_BOARD_INFO



 swiGetBoardInfo**




 None



 MVIP95_CMD_QUERY_DRIVER_INFO



 swiGetDriverInfo**




 None



 MVIP95_CMD_QUERY_LOCAL_TIMESLOT



 swiGetLocalTimeslotInfo**




 None



 MVIP95_CMD_QUERY_STREAM_SPEED



 swiGetStreamsBySpeed**




 None



 MVIP95_CMD_SET_OUTPUT



 swiMakeFramedConnection**
















 *  There is no MVIP-95 command equivalent. If your board has an MVIP-90 driver, you can access the MVIP-90 command through swiCallDriver.


 **  Calling this function on an MVIP-90 driver will return
CTAERR_FUNCTION_NOT_AVAIL.
















 
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