Information Technology Reference
In-Depth Information
Table 6-6
Common Digit-Manipulation Methods on Cisco Routers
Command
Mode
Description
[no] digit-strip
POTS dial peer
Enables or disables the default digit-stripping behavior
of POTS dial peers. Example:
no digit-strip
turns off
the automatic digit-stripping behavior under a POTS
dial peer.
num-exp
match
digits set digits
Global
Transforms any dialed number matching the match
string into the digits specified in the set string. Example:
num-exp 4... 5...
matches any four-digit dialed number
beginning with 4 into a four-digit number beginning
with 5 (4123 becomes 5123). Example:
num-exp 0
5000
matches the dialed digit 0 and changes it to 5000.
voice transla-
tion-profile
Global and POTS
or VoIP dial peer
Allows you to configure a translation profile consisting
of up to 15 rules to transform numbers however you
want. The translation profile is created globally and
then applied to any number of dial peers (similar to
an access list).
Following are four practical scenarios in which these digit-manipulation commands can
prove to be useful.
Practical Scenario 1: PSTN Failover Using the prefix Command
One of the benefits of using VoIP communication over traditional telephony is the ability
to have more than one path to a destination. Figure 6-12 shows a commonly encountered
scenario encountered.
PSTN DID Range:
480.555.5XXX
PSTN DID Range:
512.555.6XXX
PSTN
T1 CAS
1/0:1
T1 CAS
1/0:1
Arizona
Office
Texas
Office
10.1.1.1/24
10.1.1.2/24
IP WAN
V
V
5XXX Extensions
6XXX Extensions
Figure 6-12
Multiple Voice Paths
