3Com SuperStack 3 NBX, Administrator'S Manual

Page: 91 / 496

Overview of Virtual Tie Lines 91
Conference Calls Users can set up conference calls over VTLs in much the same way that
they set up conference calls with other users at their local site, or at a site
reachable by an external telephone line. On NBX 100 systems, you can
have up to four 4-person conference calls simultaneously. On a
SuperStack 3 NBX system, you can have up to twelve 4-person
conference calls simultaneously.
To be able to make conference calls between sites, you must have IGMP
(Internet Group Management Protocol) implemented on your network.
Conference Calls Using Site-Unique Extensions
In Figure 28, a user in Chicago establishes a conference call with two
users in Atlanta and one user in Dallas as follows:
1 Dial the first extension in Atlanta.
2 After the user answers, press Conference and dial the second extension
in Atlanta.
3 When the second user answers, press Conference again to connect all
three users.
4 Press Conference again and dial the extension of the user in Dallas.
5 When the fourth party answers, press Conference to connect all four
users.
Conference Calls Using Site Codes
In Figure 29, if you work in the Chicago office, to establish a conference
call with two people in Atlanta and one person in Dallas:
1 Dial the site code (62) and the first extension.
2 After the first user answers, press Conference , dial the same site code
(62) and the second extension in Atlanta.
3 When the second Atlanta user answers, press Conference again to
connect all three users.
4 Press Conference again and dial the Dallas site code (63) and then the
extension of the user in Dallas.
5 When the Dallas user answers, press Conference again to connect all
four users.