# Before You Configure Cisco HDLC

Before you configure a Cisco HDLC interface, you need to configure the physical interface over which Cisco HDLC traffic flows, described in the following chapters:

- Configuring Channelized T3 Interfaces in JunosE Physical Layer Configuration Guide
- Configuring T3 and E3 Interfaces in JunosE Physical Layer Configuration Guide

The procedures described in this chapter assume that a physical interface has been configured.