Nortel Meridian Meridian 1 Feature Description And Administration page 1443

B-channel status categories
The following are the status categories associated with the NI-2 B-channel
Service Messaging feature:
• IS - Indicates that the B-channel is in service and available for outgoing
and incoming calls.
• OOS-FE - indicates that the far-end B-channel is out-of-service.
• OOS-NE - indicates that the near-end B-channel is out-of-service.
When a B-channel at the near-end goes out-of-service, the Meridian 1 sends
a service message with OOS status to the far-end. The near-end B-channel
status is OOS-NE. On receipt of this service message, the far-end changes the
corresponding B-channel to OOS-FE.
When the near-end B-channel becomes available, the Meridian 1 sends a
service message with IS status to the far-end. The near-end B-channel is
temporarily placed in OOS-FE. On receipt of this service message, the
far-end changes the channel status to IS and returns a service acknowledge
message with the IS status to the Meridian 1. On receipt of this service
acknowledge message, the near-end B-channel is placed in service.
The near-end status takes precedence over the far-end status. For example, if
a near-end B-channel is in an OOS/NE state and receives an OOS request
from the far-end, the final status is OOS/NE.
NI-2 B-channel Service Messaging
International ISDN PRI Feature description and administration
Page 1443 of 1814