3Com Nbx 100 And Ss3 Nbx Administration Guide

Call Rerouting for Virtual Tie Lines101
Call Rerouting for 
Virtual Tie LinesTo enable the NBX system to better deal with network problems, you can 
configure the system dial plan so that some virtual tie line (VTL) calls can 
be rerouted if a VTL connection cannot be made.
VTL calls can be rerouted if:
■The dial plan contains an invalid IP address
■The remote NBX system is not responding
■All VTL channels on the remote NBX system are currently busy
■All IP addresses in the IP On-the-Fly address pool are...

102CHAPTER 2: DIAL PLAN
Figure 35   Sample Dial Plan Entries for Rerouting VTL Calls
Explanation:
The TableEntry Create command specifies that when a user on the local 
NBX system dials a six-digit number beginning with the digits 72, the call 
is routed via route 6, which is the route that normally contains only the 
VTL extension list (*0006).
To allow VTL calls to be rerouted, route 6 is configured to use both the 
VTL extension list and the Line Cards extension list (*0001). Calls that use 
route 6...

Managing Existing Virtual Tie Lines103
Successful VTL Call
If there are no network problems:
1The first line (Entry 1, OperId 1) removes the digits 72.
2The second line (Entry 1, OperId 2) prepends the IP address of the NBX 
system at site B in front of the dialed extension number. 
Unsuccessful VTL Call
If a network problem or a lack of VTL ports prevents the VTL call from 
reaching its destination:
1The third line (Entry 2, OperId 1) removes the digits 72.
2The fourth line (Entry 2, OperId 2) prepends...

104CHAPTER 2: DIAL PLAN
Figure 36   Virtual Tie LInes Tab
3Select a VTL from the list.
4Click Modify. The Modify dialog box appears (Figure 37
).
Figure 37   Modify Virtual Tie Line Dialog Box
5In the New VTL name text box, type the name you want to assign to this 
VTL. Click OK. Verify that the name change is on the Virtual Tie Lines tab. 

Managing Existing Virtual Tie Lines105
Viewing and
Resetting Virtual Tie
Line StatisticsYou can view the statistics for a VTL at any time.
To view statistics for a VTL:
1In the NBX NetSet - Main Menu window, click Device Configuration.
2Click the Virtual Tie Lines tab. 
3From the list, select the VTL.
4Click the Statistics button. The Statistics dialog box (Figure 38
) appears. 
The fields are described in Table 20
.
Figure 38   Virtual Tie Lines Statistics Dialog Box
5To reset all VTL statistics, click...

106CHAPTER 2: DIAL PLAN
Table 20   Virtual Tie Line Statistics Fields
FieldDescription
NOTE: All statistics apply to the time period since the most recent Reset command 
or since the most recent system reboot, whichever was more recent. To determine 
the starting time for the displayed statistics, compare the Last reset command with 
the time of the Last system reboot. Both are displayed at the bottom of the VTL 
Statistics window.
Number of outgoing 
VTL calls madeThe number of outgoing calls made over...

Managing Existing Virtual Tie Lines107
Enabling Audio
CompressionYou can enable or disable ADPCM (Adaptive Differential Pulse Code 
Modulation) audio compression on a system-wide basis for VTLs. The 
default condition disables audio compression.
When you enable VTL audio compression on an NBX system the VTL 
software attempts to use audio compression on all VTL calls. If the NBX 
system on the other end of the VTL call is not configured to support 
audio compression, the local VTL software attempts to...

108CHAPTER 2: DIAL PLAN
4To enable audio compression on VTL calls, click the Audio Compression 
on VTL Calls check box and then click OK.
Enabling
System-wide Silence
SuppressionYou can enable or disable silence suppression on a system-wide basis for 
VTLs. The default condition disables silence suppression. When you 
enable VTL silence suppression on an NBX system, the VTL software 
attempts to use silence suppression on all VTL calls. If the other NBX 
system is not configured to support silence...

Using a VTL Password109
Using a VTL 
PasswordIf you want to allow users on one NBX system to place VTL calls to 
another NBX system and then place long-distance (toll) calls from that 
location (this is known as hop off), you can configure a VTL password.
When an NBX system receives a VTL call from a user on another NBX 
system, it can allow that user to make long-distance calls if the incoming 
VTL call contains the password. Otherwise, such calls are not allowed. If 
you set up two classes of VTL calls...

110CHAPTER 2: DIAL PLAN
3Click the Virtual Tie Lines Password button. The Change Virtual Tie Lines 
Password dialog box (Figure 42
) appears.
Figure 42   Change Virtual Tie Lines Password Dialog Box
4Type the current administrator password in the Current Admin Password 
text box.
5Type the new VTL password in the New Virtual Tie Line Password text 
box.
Passwords are from 8 to 15 characters in length and must contain only 
letters and numbers. Upper and lower case letters are permitted.
6Retype the new...