B-Channel Service Control - NEC NEAX 2400 IPX Programming Manual

B-27

B-CHANNEL SERVICE CONTROL

1. General Description
A PBX can send a trunk maintenance (SERVICE) message to the ISDN (AT&T-#4ESS, NT-DMS100/250)
when setting or cancelling a trunk make busy using the MBTK command. This function is not provided by NI-2
protocol.
Whether "In Service" mode or "Out of Service" mode of a PBX is determined by a trunk maintenance message
from the network. (Even if a PBX sent a trunk maintenance message setting the PBX to "Out of Service" mode,
the PBX would be set "In Service" when the PBX receives a trunk maintenance message for "In Service" from
the network.)
<For AT&T>
When a PBX has been set to "Out of Service" mode after receiving a trunk maintenance message from the
network, incoming calls from the network would not be allowed.
<For NT>
Even if a PBX has been set to "Out of Service" mode after receiving a trunk maintenance message from the
network, incoming calls from the network would be allowed.
2. Operating Procedure
Using MBTK,
Set make busy to a bothway call (MB=2):
Cancel the bothway make busy (MB=0):
3. Programming
None.
SERV message
PRT
SERV ACK
IOC
SERV (Service) message = Trunk Maintenance message.
Note:
SERV (Service) ACK = Service acknowledgement.
A PBX sends a trunk maintenance message.
A PBX sends a trunk maintenance message.
NDA-24305
B-CHANNEL SERVICE CONTROL
NETWORK
(AT&T/NT)
CHAPTER 6
Page 185
Revision 1.0