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Primary Rate Interface 173
To meet the needs of the PRI provisioning, the T1 or E1 (whichever is appropriate) must be
configured to match telco requirements of framing and line code, as discussed in the preceding
sections of this chapter.
The T1/E1 controller is actually an internal CSU/DSU. It must be told which timeslots are
included in the PRI configuration. For purposes of controller configuration, the timeslot
numbering starts at 1 (1­24 for T1, and 1­30 for E1). The command syntax is mercifully limited
in the number of actual parameter choices available. Table 6-5 illustrates the options available
for T1 and E1 configuration.
Once all the appropriate information is collected, the configuration can be completed. Example
6-31 illustrates a typical T1 controller configuration.
Note that the switch type has been set. Again, this setting is based on telco-provided
information. The controller t1 0/0 command specifies the controller in slot 0, port 0. All 24
timeslots are active in the configuration. The framing is ESF and the linecode is B8ZS; both
pieces of information are telco-provided. If this information is not readily available (that is, not
provided by the telco), try using the configuration in Example 6-31.
Table 6-5
T1/E1 Framing and Line Code Options
Options
Framing*
Line Code*
T1
SF (D4)
AMI
ESF
B8ZS
E1
CRC4
AMI
NO-CRC4
HDB3
CRC4 Australia
NO-CRC4 Australia
*Framing and line code are telco-provided configuration parameters. If the controller configuration
does not match what the telco has defined, the line does not function.
Example 6-31
T1 PRI Configuration
AS5300A(config)#isdn switch-type primary-ni
!
AS5300A(config)#controller t1 0/0
AS5300A(config-controller)#pri-group timeslots 1-24
AS5300A(config-controller)#framing esf
AS5300A(config-controller)#linecode b8zs
AS5300A(config-controller)#clock source line primary
!
AS5300A(config)#interface serial 0/0:23
AS5300A(config-if)#ip address 10.12.1.1 255.255.255.0
AS5300A(config-if)#isdn incoming-voice modem