Ppp Encapsulation - Cisco ASR 9000 Series Configuration Manual

Information About Configuring Serial Interfaces
Table 20
1-Port Channelized OC-48/STM-16 SPA
Table 20 Overview: Configuring a Serial Interface on a T3 Channel
Step Task
1. Configure the SONET controller
parameters and STS stream.
2. Configure the STS stream mode for
T3 and configure the T3 controller
parameters.
3. Configure the Serial interfaces.
Cisco HDLC Encapsulation
Cisco High-Level Data Link Controller (HDLC) is the Cisco proprietary protocol for sending data over
synchronous serial links using HDLC. Cisco HDLC also provides a simple control protocol called Serial
Line Address Resolution Protocol (SLARP) to maintain serial link keepalives. HDLC is the default
encapsulation type for serial interfaces under Cisco IOS XR software. Cisco HDLC is the default for
data encapsulation at Layer 2 (data link) of the Open System Interconnection (OSI) stack for efficient
packet delineation and error control.
Cisco HDLC is the default encapsulation type for the serial interfaces.
Note
Cisco HDLC uses keepalives to monitor the link state, as described in the
page
Use the debug chdlc slarp packet command to display information about the Serial Line Address
Note
Resolution Protocol (SLARP) packets that are sent to the peer after the keepalive timer has been
configured.

PPP Encapsulation

PPP is a standard protocol used to send data over synchronous serial links. PPP also provides a Link
Control Protocol (LCP) for negotiating properties of the link. LCP uses echo requests and responses to
monitor the continuing availability of the link.
When an interface is configured with PPP encapsulation, a link is declared down, and full LCP
Note
negotiation is re-initiated after five ECHOREQ packets are sent without receiving an ECHOREP
response.
PPP provides the following Network Control Protocols (NCPs) for negotiating properties of data
protocols that will run on the link:
Cisco ASR 9000 Aggregation Services Router Interfaces and Hardware Component Configuration Guide
506
provides a high-level overview of the tasks required to configure a T3 serial interface on the
Module
"Configuring Channelized
SONET/SDH on the
Cisco ASR 9000 Series Router"
"Configuring Channelized
SONET/SDH on the
Cisco ASR 9000 Series Router"
"Configuring Serial Interfaces on
the
Cisco ASR 9000 Series Router"
508.
Configuring Serial Interfaces on the Cisco ASR 9000 Series Router
Section
Configuring a Clear Channel SONET
Controller for T3
Configuring a Clear Channel SONET
Controller for T3
How to Configure Serial Interfaces
"Keepalive Timer" section on
OL-26061-03