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Dialogic 6.2 User Manual

Page 220

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Managing Calls Using IP Telephony

November 2009

220

SIP/T38://+01-781-555-1212

ISDN://+01-781-449-9009

When the current FAX.C sample program is compiled, it takes

command line parameters to define the number dialed. With no

changes to the source code, you can replace the number with a URI

to allow it to take advantage of T.38. The sample program is

effectively IP-enabled purely by virtue of the dial string it uses.

In a SIP environment, the following command:

fax –u 0 –s [email protected] foo.pkt

initiates the following sequence of events:
1. Call control processes the URI dial string.
2. Sends it to the SIP protocol stack.
3. The SIP protocol stack sends it to the SIP redirect server.
4. The SIP redirect server tells the SIP stack where calls to

brooktrout.com should go.

Note:

Redirect and proxy servers are optional. You can send an

INVITE directly to a user client.

5. SIP stack places the call there.
6. Remote SIP proxy optionally redirects call to where it ought to go.

If the phone number string contains a prefix or characters followed

by a colon(:) and the prefix is not SIP, the software sends a return

status indicating that the number the application dialed was invalid.