Introduction to Tandem X.25 Capabilities

X25AM Parameters
B–2 065307 Tandem Computers Incorporated
Table B-2 lists the X25AM parameters for packet-level characteristics.
Table B-2. X25AM Packet-Level Characteristics (Page 1 of 2)
Network
Subscription
Parameter
Possible
Values
Default
Values
SCF
Attribute
SYSGEN
Modifier Comments
Packet
Window
1 – 15 2 L3WINDOW L3WINDOW Maximum number of outstanding
packets per virtual circuit.
Packet Size 16 – 2048 128 NOEXTFORMAT
EXTFORMAT
PACKETSIZE Specifies the data bytes per
packet. This is the default packet
size for the circuits connected to
this line. It is also the maximum
packet size that can be
negotiated for a call.
Services Two-Way
Incoming
Outgoing
Two-Way CALLS TWOWAYCALLS
NOCALLS
INCOMINGCALLS
NOINCOMINGCALLS
OUTGOING CALLS
NOOUTGOING CALLS
Applies to all subdevices
configured for the line. It can be
specified as a modifier in
SYSGEN or as a line attribute in
SCF.
Total Virtual
Circuits
1 – 254
(C-series)
1 – 511
(D-series)
32 — CIRCUITS Maximum number of virtual
circuits per line. Determines the
maximum number of subdevices
per line.
The total number of circuits
cannot exceed the number of
circuits specified in the network
subscription.
Switched
Virtual
Circuits
1 – 254
(C-series)
1 – 511
(D-series)
Calculated SVC — Subdevices (SUs) are configured
as SVCs by default. Use SCF to
specify an SU as a PVC.
The total number of SVCs cannot
exceed the total number of
circuits minus the number of
PVCs.
Permanent
Virtual
Circuits
1 – 254
(C-series)
1 – 511
(D-series)
Calculated PVC — Configured through SCF per SU.
The total number of PVCs cannot
exceed the total number of
circuits minus the number of
SVCs.
Packet
Numbering
Modulo 8
Modulo 128
Modulo 8 L3MOD L3MOD8
L3MOD128
Modulo determines the packet
sequence numbering.
Modulo 8 uses sequence
numbers 0 – 7.
Modulo 128 uses sequence
numbers 0– 127.