NEC SL2100 - Page 550

• B-Channel to Trunk Association
When an Incoming ISDN-BRI/PRI call is received, the system assigns the lowest trunk number of
the ISDN circuit to the incoming call associated with the B-Channel. When an Outgoing call is
placed using the ISDN-BRI/PRI, the system assigns the Trunk and B-Channel association according
to the chart below. This is based on the Trunk-to-Trunk Group and Trunk Group Priority assignment
in (PRG 14-05-01).
Refer to the charts below for examples(23B):
Incoming Call
Trunk
Number
B-Channel
Number
Station User
Talking on TK009
9
10
11
12
13
14
15
16
17
18
19
20
21
22
...31
1
2
3
4
5
6
7
8
9
10
11
12
13
14
...23
Incoming call from the
Network on Channel 23. In most
cases, the Network will control/select
the B-Channel used for an incoming call.
Outgoing Call
Trunk
Number
Trunk
Group
Trunk
Priority
B-Channel
Number
9 1 9 1
10 1 8 2
11 1 7 3
12 1 6 4
13 1 5 5
14 1 4 6
15 1 3 7
16 1 2 8
17 1 1 9
18 2 3 10
19 2 2 11
20 2 1 12
21 3 1 13
22 3 10 14
…31 3 ...1 …23
Station user
places outgoing trunk
all by dialing Trunk
Access code. Outgoing
call is placed on the
associated B-Channel.
In addition to PRI interface ETUs, PRI also requires a CSU/DSU Unit and interconnecting cables to
interface with the Telco.
SL2100 ISSUE 1.0
1-536
ISDN Compatibility
I