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Understanding the dial plan
Cisco TelePresence ISDN Gateways v2.0 Online help (Printable format)
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Understanding the dial plan
The ISDN gateway uses the dial plan to determine how to route calls between IP and ISDN networks.
When the ISDN gateway receives a request to initiate a new IP to ISDN or ISDN to IP call, it examines
the called number (if available), and uses the dial plan to determine whether to reject the call, find out
which number should be called to initiate the 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 for an IP to ISDN call. You can also use the dial
plan to enable the ISDN gateway to join incoming ISDN calls to the correct 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 plan and an ISDN to IP dial plan. If the
incoming part of a connection is from an IP endpoint, the IP 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 plan is 200.
Note that if you have configured the ISDN gateway to use leased line mode, then the options available on
the dial plan are different to those available in non-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
. Rules and their addition and control are nearly identical for the IP
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 match a call that has no called number,
or can specify the called number by specific number or pattern.
an
action
that is carried out if the rule is invoked
The action can be to reject the call, enter the auto attendant, enter the auto attendant and use a
TCS-4 extension (ISDN to IP only), to place the call using the original 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 64kbps or n x 56kbps
o
Restrict (56k)
: whether a call will use 56kbps. Note that if 56k is specified for a rule, but
the endpoint only supports 64kbps, then the call will be terminated rather than use
56kbps