Which of the following commands will set the line speed of a serial connection that connects to a Channel
Service Unit /Digital Service Unit (CSU/DSU) at 56 Kbps?

A.
service-module 56000 clock rate speed

B.
service-module 56k clock rate speed

C.
bandwidth 56k

D.
bandwidth 56000

Explanation:
The command service-module 56k clock rate speed will configure the network line speed for a 4-wire, 56/64-
kbps CSU/DSU module.
The command service-module 56000 clock rate speed is incorrect because the speed must be stated in the
form 56k (for Kbps), rather than 56000.
The bandwidth command is used to limit the amount of bandwidth used by an application when utilizing Quality
of Service (QOS). It does not set the line speed of a serial connection that connects to a Channel Service Unit /
Digital Service Unit CSU/DSU. Therefore, both the bandwidth 56k and the bandwidth 56000 commands are
incorrect.
Objective:
WAN Technologies
Sub-Objective:
Describe WAN access connectivity options

Cisco IOS Interface and Hardware Component Configuration Guide, Release 12.4T > Part 2: Serial Interfaces
> Configuring Serial Interfaces > 2-Wire and 4-Wire, 56/64-kbps CSU/DSU Service Module Configuration Task
List > Setting the Network Line Speed