Meridian America Link/Customer Controlled Routing - Manual (Page 33)

Chapter 2: Overview of Meridian Link 15
Meridian Link Release 5C/CCR Release 3C Installation and Upgrade Guide
SFN (login) message with agent ID This feature sends an unsolicited
message to the host application when an AST/Acquired agent logs in by
manually pressing the MSB key on the ACD set or by invoking the ACD set
feature through the Set Feature Invocation (Login) message. The existing
SFN Login message has been enhanced to provide an optional four-digit
Agent ID at the time of logging, enabling the agent to log in at different
positions.
Note: X11 Release 24 is required to support this feature.
Link overview
Although Meridian Link effectively provides a single link between the host
computer and the Meridian 1 system, from an administrative and
maintenance standpoint there are actually three links.
Link 0 The link between the IPE Module or Application Module and
Meridian 1 is called link 0 or Application Module Link (AML).
Link 1 The link between the IPE Module or Application Module and the
host computer is called link 1, the Host Link, or the Meridian Link.
Link 2 The link between the IPE Module or Application Module and
Meridian Mail is called link 2 or the Meridian Mail Link (MML).
AML and the Host Link (or Meridian Link)
The AML (link 0) uses the LAPB protocol to transfer command and status
messages, primarily to perform call-processing functions. The Host Link or
Meridian Link (link 1) uses an X.25 switched virtual circuit or a TCP/IP
protocol to transfer application messages.
In data communication terms, the Meridian Link interface begins with the
physical (RS-232) layer, upon which the link (LAPB) and network (X.25 or
TCP/IP) layers are established. Messages are then sent across the link
between the host computer and Meridian 1 at the application layer level.
If the link uses an X.25 or TCP/IP connection, the host application
communicates with the Meridian 1 switch using Meridian Link formatted
messages.