BELGACOM Forum 526, Руководство по монтажу и пусконаладке, Страница: 150 / 232

Point-to-Point Connection Lines 148
PBX Networking
Point-to-Point Connection
Lines
There are different types of lines available for an point-to-point
connection between two PBXs, depending on the distance
between them.
Direct Connection
This type of ISDN point-to-point connection joins the two systems
directly to each other using a crossover twisted-pair cable. An S
0
connection can be used for distances up to 1,000 metres, while an
S
2M
connection can span up to 250 meters. Normally one PBX is
the protocol master for all three layers, and the other PBX is the
protocol slave for all three layers.
Direct connection
Use the RJ45 jacks on one of the external S
0
ports for an S
0
con-
nection between two Forum 525/526s. You can use the corre-
sponding pressure terminals for S
0
ports on interface cards.
Wiring of a direct connection
Note: If you use an S
0
port on an interface card (pressure termi-
nal) and an S
0
port with an RJ45 jack for the direct connection,
make sure you make the necessary changes to the port assign-
ment (see S
0
Ports on Interface Cards starting on page 39).
PBX 1
L1 master
L2 master
L3 master
PBX 2
L1 slave
L2 slave
L3 slave
1 2 3 4 5 6 7 8
8 7 6 5 4 3 2 1
PBX 1, S
0
ext
PBX 2, S
0
ext
(RJ-45 socket)
PBX 1, S
2M
PBX 2, S
2M
(Pressure clamps)
Rx+ Rx- Tx+ Tx-
Rx+ Rx- Tx+ Tx-