Loopback Connectors

Loopback connectors must have the following sets of pins tied together:

DB-15
EIA-232
Male
 
DB-25
EIA-232
Female
 
DB-25
V.35
Female
 
DB-15
X.21
Female
 
DB-25
EIA-530/422
Female
 
RJ-45
Telco
2,3
2,3
2, 3
2, 4
2, 3
1, 8
4,5
4,5
4, 5
3, 5
4, 5
2, 7
6, 8, 15
6, 8, 20
6, 8, 20
6, 7
6, 8, 20
 
12,13
17, 24
9, 11
9, 11
9, 11
 
 
 
14, 16
10, 12
14, 16
 
 
 
17, 24
13, 14
17, 24
 
 
 
 
 
13, 19
 
 
 
 
 
10, 22, 23