X25AM Configuration and Management Manual

Using the NETID Modifier
X25AM Configuration and Management Manual—523424-004
D-2
Port Numbering (Subaddressing)
Port Numbering (Subaddressing)
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For NETID and REMOTENET, port numbers are often referred to as
subaddresses.
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NETID determines the location for the called (in this case the local DTE) DTE’s
port number in an incoming call: the port number can be either part of the called
address or part of the call user data. When a port number cannot be found or
calculated, it is assumed to be zero.
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NETID also determines whether X25AM appends the calling subdevice port
number to the LINE SRCADDR to form the calling address in call requests.
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REMOTENET determines the location for the called DTE’s port number in a call
request (DTE to DCE). The port number can either be part of the called address or
part of the call user data.
Default PAD Profiles
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PAD profiles are associated only with REMOTENET.
•
Some networks require a default PAD profile that differs from the standard default
profile. Even though only some values may be different, an entire profile must be
available.
•
Default parameter sets have an internal and an external (actual) format. The
Interactive Terminal Interface (ITI) protocol constructs the internal format. ITI also
translates the actual format.
•
If you alter parameters, the alterations affect the internal format. ITI then translates
the altered internal format. The alteration to the internal format may not result in
the same alteration to the external format. The internal format and external (actual)
formats may be different. The external (actual) format is sent to the PAD.
•
Complete PAD profiles are described in PAD Profiles on page D-8.
Special Network Requirements
Network-dependent facilities are associated only with NETID.
The 1976 TELENET national facility for flow-control negotiation is an example of a
special network requirement. Only Telenet uses it.