Aastra OpenCom 100 series, Mounting And Commissioning User Manual

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PBX Networking
160
Example: In the above case you could reverse the L1 slave/master setting for the con-
nection between PBX 1 and PBX 3. However, if you then activate the setting
L1 sync possible for the port of PBX 1, this may cause parts of the PBX network to
stop functioning temporarily.
When applying the L1 clock of trunk lines, you can assume that the public network is
“clock-aligned”. So, in the above example, you can connect additional trunk lines to
one of the PBXs.
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
connection between two
OpenCom 100s. You can use the corresponding pressure terminals for S
0
ports on
interface cards.
PBX 1
L1 master
L2 master
L3 master
PBX 2
L1 slave
L2 slave
L3 slave