Product specifications
Chapter 5.Loop Back & BERT Testing 
62 
May 2011 
BERT for system test 
  For a system test, use the remote site’s E1 link local digital or payload loop back or data port 
local digital loop back, to return the data back to the local DTE over the E1 link, as shown in Figure 
5-10. Additionally, you may use the local site’s E1 link remote analog, remote payload or Data Port 
V.54 loop back to return the data back to the local DTE. 
Figure 5-10. BERT used for system test 
Remote Site: 
E1 Link local digital (shown) or payload 
loop back; Data Port local digital loop 
back. 
Local Site: 
E1 Link Remote analog or payload 
loop back; Data Port V.54 loop 
back (shown). 
DTE 
DSU 
E1
CSU 
LOCAL ETU-01A 
DTE 
DSU 
CSU 
REMOTE ETU-01A 
Generator 
Tester 










