Specifications

Overview of Dial Interfaces, Controllers, and Lines
T1 and E1 Controllers
DC-10
Cisco IOS Dial Technologies Configuration Guide
Figure 8 Remote Office LAN Dialing In to Headquarters
T1 and E1 Controllers
Cisco controllers negotiate the following parameters between an access server and a central office: line
coding, framing, clocking, DS0/time-slot provisioning, and signaling.
Time slots are provisioned to meet the needs of particular network scenarios. T1 controllers have
24 time slots, and E1 controllers have 30 time slots. To support traffic flow for one ISDN PRI line in a
T1 configuration, use the pri-group command. To support traffic flow for analog calls over a
channelized E1 line with recEive and transMit (E&M—also ear and mouth) signaling, use the cas-group
1 timeslots 1-30 type e&m-fgb command. Most telephone companies do not support provisioning one
trunk for different combinations of time-slot services, though this provisioning is supported on Cisco
controllers. On a T1 controller, for example, time slots 1 to 10 could run PRI, time slots 11 to 20 could
run channel-associated signaling (CAS), and time slots 21 to 24 could support leased-line grouping.
The following example configures one of four T1 controllers on a Cisco AS5300 access server:
Router# configure terminal
Router(config)# controller t1 ?
<0-3> Controller unit number
Router(config)# controller t1 0
Router(config-controller)# framing esf
Router(config-controller)# linecode b8zs
Router(config-controller)# clock source line primary
Router(config-controller)# pri-group timeslots 1-24
Router(config-controller)#
This example supports modem calls and circuit-switched digital calls over ISDN PRI.
Non-ISDN Channelized T1 and Channelized E1 Lines
A channelized T1 or channelized E1 line is an analog line that was originally intended to support analog
voice calls, but has evolved to support analog data calls. ISDN is not sent across channelized T1 or E1
lines. Channelized T1 and channelized E1 lines are often referred to as CT1 and CE1. These channelized
lines are found in “old world,” non-ISDN telephone networks.
PC sending e-mail
to headquarters
PC
Hub
NT server
Cisco 1600
remote office
router
Cisco 3640
headquarters
gateway router
BRI PRI Fast
EthernetPSTN/ISDN
PPP
14053