3Com NBX 100 Administrator's Manual page 190

190 C 3: D
HAPTER EVICE
C
ONFIGURATION
3 Select the span you want to modify from the Span List. The number of
channels supported per span depends on the configuration of the Digital
Line Card. E1 cards support 30 channels per span.
4 Click Modify.
5 Make the desired changes. Click the Help button for more information
about dialog box fields.
6 Click Apply.
7 Enable the On Line check box to bring the span online.
Before the span can come online, the board must be online.
8 Click Apply or OK for the changes to take effect.
Configuring Partial E1 Lines
Some telephone companies offer an E1 line that has less than the
maximum number of channels implemented. This is called a Fractional,
Partial, or Subequipped E1. Example: To reduce near-term costs, you may
decide to purchase 15 channels now and implement more later.
Some telephone companies offer Partial E1 lines as their standard
offering and provide fully implemented E1 lines only if you make a
specific request. If you are unaware of this, outbound calls using the E1
line may fail because the system places outbound calls using high
numbered channels first, and a Fractional E1 typically has the lower
numbered channels implemented.
In the Span Status dialog box, under Details of last five calls, if you see the
error message REQ_CHANNEL_UNAVAIL, determine if the error is caused
by a Partial E1 by following these steps:
1 Remove the highest numbered channel from service (set it to offline in
the Modify Channel dialog box) and retry the outbound call.
2 Continue to remove channels until an outbound call succeeds.
3 When the first outbound call succeeds, the highest numbered channel
still in service represents the number of active (provisioned) channels in
the Partial E1.
4 Create two groups. Put all of the active channels in one group, and all of
the inactive channels in the other. Mark the active group "online" and
the inactive group "offline."