ADTRAN T1-FT1 user manual Network Loopbacks, Tsu

Chapter 1. Introduction

Network Loopbacks

There are two types of network loopbacks; see Figure 1-7.

•Line Loopback: loops all of the received data back toward the network. The transmitted data is the identical line code that was received, including any bipolar violations or framing errors.

•Payload Loopback: similar to Line loopback, except that the framing is extracted from the received data and then regenerated for the transmitted data.

TSU

NI CSU

DS1

Payload Loopback

Line Loopback

V.35

Interface

Figure 1-7. Network Loopback Tests

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