Dialogic 6.2 Manuale Utente

Managing Calls Using IP Telephony

November 2009

219

The following section provides information about SIP functionality 

and processes. For a detailed introduction to the SIP protocol, see 

To make an outgoing connection using the IP, your application must 

know the IP address of a local proxy server which is responsible for 

forwarding the SIP call towards its final destination. In a typical 

environment, the proxy server is the local IP to PSTN gateway. For 

more information about using proxy servers, see 

. 

To receive incoming calls using the internet, you must register your 

location so that proxy servers can locate you.

For more information about configuring proxy servers, see the 

installation and configuration guide that came with your software 

and the Bfv API Reference Manual, Volume 6, Appendix A.

If your application either does syntax verification/modification of the 

dialed string or it is desirable to do number translation or lookup 

without modifying the application, then the application needs to 

perform number translation. 

Channel numbers enable your application to differentiate between 

types of call in the context of the Call Control Bfv API. SIP and other 

IP protocols use a Uniform Resource Identifier (URI). The software 

detects and recognizes the format of the dial string and sends the 

call to the appropriate channel. In Brooktrout SDK 4.0 and beyond, 

the dial strings follow the URI syntax, so tel: and fax formats are not 

supported and must be reformatted by your application.

Prefixes to dial strings are provided as a means for your application 

to behave intelligently by supporting channel selection in hybrid 

systems. Prefixes are optional.

Using prefixes, dial strings can also be pre-qualified by your 

application as in the following example:

SIP/T38://xxxxx@brooktrout.com