Specifications

Low-Speed Serial Interface Examples
Configuring Serial Interfaces IC-129
The following example shows some typical synchronous serial interface configuration commands
available when the interface is in synchronous mode:
interface serial 2
physical-layer sync
ip address 1.0.0.2 255.0.0.0
no keepalive
ignore-dcd
nrzi-encoding
no shutdown
Change between Controlled-Carrier and Constant-Carrier Modes Examples
The following example shows how to change to controlled-carrier mode from the default of
constant-carrier operation:
interface serial 2
half-duplex controlled-carrier
The following example shows how to change to constant-carrier mode from controlled-carrier mode:
interface serial 2
no half-duplex controlled-carrier
Tune Half-Duplex Timers Example
The following examples show how to set the cts-delay timer to 1234 milliseconds and the
transmit-delay timer to 50 ms.
interface serial 2
half-duplex timer cts-delay 1234
half-duplex timer transmit-delay 50
Cisco 4000 Series Router with 2T16S Serial Network Processor Example
The 2T16S network processor module provides high-density serial interfaces for the Cisco 4000
series routers. This module has two high-speed interfaces that support full-duplex T1 and E1 rates
(up to 2 MB per second) and 16 low-speed interfaces. The 16 lower-speed ports can be individually
configured as either synchronous ports at speeds up to 128 kbps or as asynchronous ports at speeds
up to 115 kbps.
For the slow-speed interfaces, both synchronous and asynchronous serial protocols are supported.
For for the high-speed interfaces, only the synchronous protocols are supported. Synchronous
protocols include IBM’s BSC, SDLC, and HDLC. Asynchronous protocols include PPP, SLIP, and
ARAP for dial-up connections using external modems.
The following example shows a Cisco 4500 router equipped with two 2T16S serial network
processor modules and two conventional Ethernet ports. The router is configured for WAN
aggregation using X.25, Frame Relay, PPP, and HDLC encapsulation. Serial interfaces 0, 1, 18, and
19 are the synchronous high-speed interfaces. Serial interfaces 2 through 17 and 20 through 35 are
the synchronous/asynchronous low-speed interfaces.
version 11.2
!
hostname c4X00
!
username brad password 7 13171F1D0A080139
username jim password 7 104D000A0618
!