Specifications

Reference Guide
2-29
Applications ISDN Primary Rate Interface (PRI) Server
2.6.6 PRI to FXS termination
This integrated access system is used to connect calls to an analog modem rack as shown in
Figure 2-18. This application is usually used to terminate a mix of ISDN originated calls and
analog modem originated calls to the same destination. This is common in remote access
applications where there is a need to support both existing analog modem applications and
new digital ISDN connections over the same network facility. End users can migrate as needed
from analog modems to ISDN, sharing the same facility, and maximizing utilization of
network bandwidth. The IAD receives all calls, examines the called number and routes the
analog modem calls to the FXS hunt group. ISDN data calls are routed directly to the ISDN
remote access server. This application only works for inbound calls since the modems in the
rack can not be used to dial out through the IAD over ISDN.
Figure 2-18. PRI to FXS Termination
2.6.7 Routing Capabilities
2.6.7.1 Call Routing
This integrated access system can be simultaneously connected to several Network and User
side ISDN PRI facilities and to a user’s data terminal equipment such as a video codec or LAN
router. DTE is usually connected to the system’s HSU cards.
Any call originating from a HSU port (with the exception of the Switched HSU card), must
be associated with a call profile. The call profile specifies which D channel is to carry the call.
Any device attached to an HSU port that is able to receive incoming calls is assigned a unique
number that allows the system to route the incoming call to it. Optionally, a shared hunt group
phone number can be assigned to the same HSU port.
PRI
FXS
ISDN
Network
Modem Rack
ISDN Remote
Access Server
PRI
Mail
Server
LAN
IAD
PSTN
Modem