D-Link DVX-7090 사용자 설명서

다운로드
페이지 83
 
Configuration How-to’s  
 
5.9 
H
OW TO USE 
M
ATCH AND 
P
ATTERN FIELDS IN THE 
R
OUTING 
TABLE
 
Regular expressions are character strings used to build search patterns. Regular expressions 
also provide a powerful string handling tool. Regular expressions may include both 
alphanumeric characters, i.e. letters and digits normally used in writing and the so-called 
metacharacters. Metacharacters  are symbols that have special meaning and use.  
In this application you use regular expressions to define match (
) and pattern 
(
) strings.  
The 
 field is for regular expressions that define a match pattern for the source or 
destination number search.  
The most instrumental and frequent metacharacters that you may need to use in match 
patterns include: 
^ denotes the beginning of the match string. For example, ^56  matches a string 
starting with “56”. 
$ stands for the end of a string. For example, 88$  corresponds to any set of 
characters ending with “88”. 
.
 signifies any character 
\d means any decimal digit. 
When the number of symbols in the sought string is unknown, use special metacharacters 
called quantifiers. The most commonly used quantifiers are as follows: 
– * denotes any number of something, for example, X* means any number of X’s; 
– ? stands for zero or 1 entry of a character, for example, X?  means none or one X; 
– +  is used to express one or more entries of a character, for example you type X+ 
to signify 1 or more entries of X, and finally 
– X{n} denotes exactly n number of Xs. 
 
The field 
 is designed for entering source and destination number translation rules. 
The need to transform the source or destination number often arises before passing the 
number to a particular service. If no changes are required, use the following regular 
expression  
.*
.  
When number transformation is necessary without passing it to any particular service 
afterwards, select one of the following commands from the list: 
•  Continue – the modified number is passed to the next rule in the Routing table; 
•  Restart – the modified number is passed to the first rule of the Routing table. 
 
Brackets are used to mark parts of the number extracted during call handling, for example 
^(56.*). In the field 
 the marked parts are referred to as $n. In the expression $n n 
represents a positive integer (greater than or equal to one) that identifies the number of the 
brackets occurrence (e.g. $1 denotes the first set of brackets, $2 means the second set of 
brackets etc). 
DVX-7090 VoIP Router 
page 63 of 83