Cabletron Systems 1800 - Manual (Page 115)

Configuring X.25 8-23
To illustrate how calls will be distributed among these lines, assume there are no calls
on any line. The lines will have the following process variables:
Line Speed M/w U
0,0 2400 4 4
1,0 4800 2 2
1,1 failed
1,2 9600 1 1
A Call Request will be routed on line 1,2, since it has the lowest U . The next Call
Request will produce a new calculation for U for all lines, and will again be routed on
the lowest U line:
Line U
0,0 4
1,0 2
1,1 failed
1,2 2
In this case, other system factors will determine whether line 1,0 or line 1,2 will be
selected. If we assume 1,0 is selected, the new values of
U will be as follows, giving
line 1,2 the next call:
Line U
0,0 4
1,0 4
1,1 failed
1,2 2
If the database is changed and lines are added or deleted from the routing path config-
uration, or if lines become operational or not operational, the next Call Request will
trigger new
U values based on the lines available at the moment. As operational lines
fill up their LCNs they are excluded from getting new calls. If all operational lines
have all LCNs in use, new calls will be cleared.