Digital Line/Net; Codec Line/Net; Figure 6-5. Digital Line/Network Loopback; Figure 6-6. Codec Loopback - ADTRAN MX2800 STS-1 System Manual

Section 6, Loopbacks
VT/Port Loopbacks

Digital Line/Net

A Digital Line/Net loopback
and local loop directions. Both loopbacks occur at the T1/E1 LIU. The network side loopback occurs deep
into the LIU through the receiver, receive equalizer, transmit jitter attenuator, and finally, through the
T1/E1 transmit drivers.
STS-1
LIU

Codec Line/Net

A Codec Line/Net loopback
and local loop directions. Both loopbacks occur at the T1/E1 codec. Both the network and the local loop
side of the loopback are executed at the edge of the codec, completely testing the STS-1 mapper and the
T1/E1 LIU.
STS-1
LIU
6-4
(Figure 6-5) performs a loopback of the selected T1/E1 in both the network
STS-1
MAPPER

Figure 6-5. Digital Line/Network Loopback

(Figure 6-6) performs a loopback of the selected T1/E1 in both the network
STS-1
MAPPER

Figure 6-6. Codec Loopback

MX2800 STS-1 User Manual
CODEC T1/E1 LIU
(1 of 28) (1 of 28)
CODEC T1/E1 LIU
(28 of 28)
(28 of 28)
CODEC T1/E1 LIU
(1 of 28) (1 of 28)
T1/E1 LIU
CODEC
(28 of 28) (28 of 28)
61204659L1-1A