ZyXEL Communications ISG50 User Manual

 Chapter 34 Call Services

ISG50 User’s Guide

Each field is described in the following table.

Configuration > PBX > Call Service > Call Block

Enable Anonymous 
block

Select this to block calls without caller ID from being routed by the ISG50. Clear it to 
allow any incoming calls routed by the ISG50.

Black list

Select Disable to turn call blocking off on the ISG50. Select Enable to turn on call 
blocking on the ISG50. When you select Enable, use the table that displays to set up a 
list of phone numbers that are not allowed to call into the ISG50. 

Add

Click this to create a new entry. Select an entry and click Add to create a new entry 
after the selected entry.

Edit

Double-click an entry or select it and click Edit to modify it. 

Remove

To remove an entry, select it and click Remove. The ISG50 confirms you want to 
remove it before doing so.

#

This field is a sequential value, and it is not associated with a specific entry.

Number

This is a telephone number the ISG50 blocks from calling extensions in your telephone 
network. When adding or editing an entry, type the telephone number. 

You can also use the letters X, Z and N to represent numbers you want to block. The 
letter “X” represents any digit from 0-9, Z any digit from 1-9 and N any digit from 2-9. 
For example, enter 023XXXXXX to block any 9 digit number that starts with 023 from 
calling the extensions configured on the ISG50. 

Furthermore, you can use the period (.) as a wildcard, to block any numbers that begin 
with a pattern of digits you specify. For example, enter 555. to block any numbers 
starting with the string 555 from calling the extensions configured on the ISG50.

Apply

Click this to save your changes.

Cancel

Click this to set every field in this screen to its last-saved value.