Understanding the dial plan
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Understanding the dial plan
The Cisco TelePresence ISDN Gateway uses the dial plan to determine how to route calls between IP
and ISDN networks. When the ISDN Gateway receives a reques t to initiate a new IP to ISDN or ISDN to
IP call, it examines the called number (if available), and us es the dial plan to determine whether to reject
the call, find out which number should be called to initiate t he outgoing part of the call, and to check the
allowed call bandwidth.
There are a number of different ways in which you can use the dial plan. For example, you can use the
dial plan to enable callers to use a particular bandwidth f or an IP to ISDN call. You can also use the dial
plan to enable the ISDN Gateway to join incoming ISDN calls to the c orrect conference on an MCU. (For
example dial plans, refer to Example dial plan rules.)
The dial plan is actually divided into two; an IP to ISDN dial p lan and an ISDN to IP dial plan. If the
incoming part of a connection is from an IP endpoint, the I P to ISDN dial plan is used; if it is from an ISDN
endpoint, the ISDN to IP dial plan is used. The behavior of the two dial plans is nearly identical, and the
sections below only make a distinction between the two where differences exist.
The maximum number of rules that can be added to each dial pl an is 200.
Note that if you have configured the ISDN Gateway to use le ased line mode, then the options available
on the dial plan are different to those available in non-leased line mode. For information about configuring
dial plans in leased line mode, refer to Adding and upd ating dial plan rules in leased line mode.
Refer to the sections below for more information about the use and administration of dial plans:
Rules
Using rules
Rule ordering
Rules
Dial plans are administered using rules. R ules and their addition and control are nearly identical for the I P
to ISDN and ISDN to IP dial plans.
Each rule has a name and comprises:
a Condition that must be matched for the rule to be invoked
The condition can be set to match any called number, to m atch a call that has no called number,
or can specify the called number by specific number or patt ern.
an Action that is carried out if the rule is invoked
The action can be to reject the call, enter the auto attendan t, enter the auto attendant and use a
TCS-4 extension (ISDN to IP only), to place the call using the ori ginal dialed number, or to
specify the number/address to call.
a set of Additional parameters that modify the action:
o Call type: specifies whether the call is a normal video call, a telephone call, or a video
call that supports legacy ISDN endpoints that use n x 64k bps or n x 56kbps