Operation, administration, and maintenance (OAM) features 2-55

Figure 2-29

Electrical Loopback types

 

Facility Loopback

Terminal Loopback

 

 

 

 

 

 

 

VT equipped with DS1 AIS

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

for async mapping or VT AIS

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

for byte synch mapping

 

 

 

 

 

 

 

 

DS1

 

 

 

 

 

 

 

 

DS1

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

DS1 AIS

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Facility Loopback

Terminal Loopback

STS equipped

 

with DS3 AIS

 

DS3

DS3

 

DS3 AIS

Facility Loopback

Terminal Loopback

AIS

EC1

EC1

Copy of signal on optics

Optical loopback

Optical facility loopbacks

Optical loopback functionality provides maintenance personnel the capability to test portions of optical circuits for signal continuity by having the OC-n circuit packs loopback test signals that are sent to them on either the terminal or facility side of the connection. Sectioning of a SONET path facilitates remote fault isolation.

Note: Site Manager supports provisioning of optical loopbacks.

Figure 2-30illustrates an optical facility loopback.

Planning and Ordering Guide—Part 1 of 2 NTRN10AN Rel 12.1 Standard Iss 1 Apr 2004

Page 93
Image 93
Nortel Networks 3500, NTRN10AN manual Optical loopback, Electrical Loopback types, Optical facility loopbacks