User guide

August 2001 165

Switching Calls through the MVIP-90 Bus

When a computer telephony system processes a call, it connects

the inbound or outbound line with the appropriate resource,

such as VP or another line. That other resource can be on the

same board, or on a different board in the system. The process

of routing data between resources on different boards is called

switching. All line resources have a CODEC, which

codes/decodes the analog voice signal to digital data. It is the

digital representation of the analog signal that a switch block

switches between resources.

Only boards with a switch block, such as the RTNI or Vantage

PCI boards, can perform switching functions. Although the

RDSP/xx000, Vantage VPS, and Vantage VRS boards can

connect to the MVIP bus, they do not have a switch block and

can not switch data.

Boards with switching capabilities have access to all MVIP

streams and timeslots. The Vantage VPS, Vantage VRS, and

RDSP/xx000 boards, on the other hand, can only access their

assigned streams. Data placed on the DSix stream goes directly

to the resources of the board assigned to that stream. The

resource places data on the DSox stream.

Boards with switching capability use internal data streams for

their line or VP resources. These internal streams carry data

from lines coming in to the RTNI board. They do not connect to

the MVIP bus and cannot be accessed by resources outside the

board they are internal to. When you make a connection

between an internal resource and the MVIP bus, you specify a

board handle so the application knows which switch block

transfers data from its internal stream.