Information Technology Reference
In-Depth Information
PBX System
DS0 Channels 1-5
Demultiplexer
Device
DS0 Channels 6-24
T1 1/0
PSTN
Figure 6-3
Provisioning Multiple Connections with a Single T1 Interface
Note:
The demultiplexing device shown in Figure 6-3 allows you to break the single T1
interface into multiple interfaces with specific channel assignments.
Notice that the
ds0-group
command also allows you to set the signaling type. This gives
you the ability to connect to many different network types. A PSTN carrier typically uses
FXO loop start signaling over the T1 CAS connection (this might differ depending on
your location and service provider). PBX systems often support one of the various Ear and
Mouth (E&M) signaling types.
After you enter the
ds0-group
command, the router automatically creates a voice port for
each time slot you provision, as you can see from the
show voice port summary
output in
Example 6-5. The port is listed as 1/0:1 because 1/0 represents the physical interface and
the additional 1 represents the DS0 group number. Make a note of this port identifier be-
cause you need it to configure the dial peers. Each port listed represents a different chan-
nel on the T1 interface.
The digital T1/E1 interface for a CCS (ISDN PRI) PSTN connection is configured using
similar syntax as the CAS. Example 6-6 demonstrates a configuration that provisions all
24 time slots of a VWIC interface as a PRI PSTN connection.
Example 6-6
Configuring a T1 CCS PSTN Interface
CME_Voice(config)#
isdn switch-type ?
primary-4ess Lucent 4ESS switch type for the U.S.
primary-5ess Lucent 5ESS switch type for the U.S.
primary-dms100 Northern Telecom DMS-100 switch type for the U.S.
primary-dpnss DPNSS switch type for Europe
primary-net5 NET5 switch type for UK, Europe, Asia and Australia
