As mentioned in the post on the other forum, TTT said PRI is not currently available on the Partner. Since you explained the problem you are having is someone calling back and getting a busy, one solution is putting the lines in circular hunt or "round-robin" hunt. I know Sprint (Centel) has that type of line hunting. It is in all DMS100 switches.
The following is a segment from a PRI service description:
Contents Last Updated: 3/24/2005
Integrated Services Digital Network Primary Rate Interface (ISDN PRI)
Description
Integrated Services Digital Network Primary Rate Interface (ISDN PRI) is a complex voice and data service that
provides high-volume access to the public switched telephone network (PSTN). This service lets you transmit
data at high speeds to accommodate voice, data, image, and video over the same digital facilities.. ISDN
PRI provides 23 digital channels over one transport line (a 24th channel carries signaling information). This
service offers you one T1 circuit with 23 separate voice lines or a combination of services.
ISDN PRI consolidates its 23 voice or data service channels on one 1.544 Mbps transport line into a PBX or
computer network. It simplifies PBX access to many applications, including LAN-to-LAN connectivity and
videoconferencing. When used for trunking, you improve PBX capacity and can transmit voice, WATS, toll-free,
and circuit-switched data calls. With call-by-call software, you can use the same line for different voice or data
applications as needed.
You can use one D channel to control multiple ISDN PRI lines, freeing the 24th channel on additional ISDN PRI
circuits to increase capacity. Backup D channels provide a contingency for inoperable D channels. If a failure
occurs, a predetermined D channel on another ISDN PRI connection automatically takes over call control
signaling for your calls.
The speed of ISDN PRI opens opportunities for a whole new breed of applications. Telecommuting, teleradiology,
remote healthcare, distance learning, remote broadcasting, sound transfer, and CAD/CAM engineering are some
of the uses for ISDN PRI.
ISDN PRI is a high-speed digital connection for voice and data between your PBX and the SBC PSTN. You can use
the full capacity of each ISDN PRI B channel (23 of them at 64 Kbps) for data because the 64 Kbps D channel
sends all the signals required to connect and disconnect each channel's calls. By aggregating these channels, you
can transmit data up to 1.544 Mbps through the public switched network. Alternatively, you can use each channel
for direct inward dial, direct outward dial, and various other call types.
Hope this helps!
....JIM....