Specifications

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Cisco 7100 Series VPN Router Installation and Configuration Guide
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Chapter 4 Performing a Basic Startup Configuration
Configuring a Router
Configuring the ATM Interfaces
The Cisco 7120-AT3 provides one and the Cisco 7140-2AT3 provides two high-speed, ATM ports that
support full-duplex operation at T3 (45-Mbps) speeds. The Cisco 7120-AE3 provides one and the
Cisco 7140-2AE3 provides two high-speed, ATM ports that support full-duplex operation at E3
(34-Mbps) speeds. The Cisco 7120-SMI3 provides one and the Cisco 7140-2MM3 provides two ATM
ports that support full-duplex operation at OC-3c/STM1 single-mode intermediate reach or multimode
(155-Mbps) speeds. The default settings and the commands to change the defaults are listed in Table 4-5.
Perform a basic interface configuration using the procedure below.
Note Additional configuration commands may be required, depending on your system requirements and the
protocols you plan to route on the interface.
At any time, you can exit the privileged level and return to the user level by entering disable at the
prompt as follows:
Router# disable
Note Information on configuring virtual circuits is described in the “Configuring ATM” chapter of the
Wide-Area Networking Configuration Guide publication.
Step 1 At the Router (config)# prompt, enter the interface type slot/port command to enter the interface
configuration mode. In this example, the serial port 0 is configured:
Router(config)# interface atm 1/0
Router(config-if)#
Table 4-5 ATM T3, E3, and OC3 Interface Defaults
General Attributes Default Value Command
ATM clock Receive clock atm clock internal
no atm clock internal
MTU size 4470 bytes mtu bytes (64 to 9188)
T3 Attributes
Line build-out Short atm lbo {short | long}
ATM DS3-scramble Not enabled atm DS3-scramble
no atm DS3-scramble
ATM DS3 framing cbitadm atm framing {m23plcp | cbitplcp | m23adm |
cbitadm}
E3 Attributes
ATM E3-scramble Not enabled atm e3-scramble
no atm e3-scramble
ATM E3 framing G. 832 atm framing {g832adm | g751adm | g751plcp}
OC3 Attributes
SONET framing sts-3c atm sonet stm-1
no atm sonet stm-1