Expand Configuration and Management Manual (G06.24+)

Subsystem Description
Expand Configuration and Management Manual523347-008
18-3
Expand Line-Handler Processes
A multi-CPU path is created by associating Expand line-handler processes with one
another using the SUPERPATH_ON modifier. Each line-handler process that is a
member of a multi-CPU path is configured in a different processor.
Expand Line-Handler Process Types
Expand line-handler processes can be categorized as follows:
Those that contain all the protocol levels necessary to perform both path and line
functions. These include the following types of Expand line-handler processes:
°
Direct-connect
°
Satellite-connect
Those that require another type of process to perform line functions. These include
the following types of Expand line-handler processes:
°
Expand-over-NAM
°
Expand-over-IP
°
Expand-over-ServerNet
°
Expand-over-FOX
°
Expand-over-ATM
The different types of Expand line-handler processes are described in the following
subsections. For information on how to configure Expand line-handler processes, refer
to Section 5, Configuration Overview.
Direct-Connect and Satellite-Connect Expand Line-Handler
Processes
The direct-connect line-handler process implements the High-Level Data Link Control
(HDLC) Normal protocol. This type of Expand line-handler process is provided for use
with conventional voice-grade leased-line and switched-line facilities, private facilities,
and fractional Transmission Group 1 (T1) facilities.
The satellite-connect line-handler process implements the satellite-efficient version of
the HDLC protocol, the HDLC Extended Mode protocol. Unlike the HDLC Normal
protocol implemented by direct-connect Expand line-handler processes, the HDLC
Extended Mode protocol uses the maximum window size of 61 frames (the maximum
number of outstanding frames before an acknowledgment is required) and implements
the selective reject feature. Selective reject causes only frames that arrive in error to
be retransmitted.
Note. The path and line functions of an Expand line-handler process are described in more
detail in Expand Subsystem and the OSI Reference Model
on page 18-9.