International Dialing Prefix; Call-By-Call - Polycom ViewStation FX User Manual

Chapter 4
ViewStation FX/VS 4000 User's Guide
If ISDN is selected, the numbering plan is identified to the upstream
switch as ISDN, and the number type, which is either national or
international, is determined from the dialed phone number. If the
dialed phone number starts with the international dialing prefix that
is currently selected, the type is set to the international and the prefix
is removed from the number before the number is sent to the
upstream switch. Otherwise, the number is marked as national and
passed to the upstream switch without modification.
When ISDN is selected, the international dialing prefix is not
recognized if any other access code or prefix precedes the
international dialing prefix. The phone number must begin with the

international dialing prefix.

The default value, Unknown, is preferred and should work in most
cases. Unknown should work with all properly configured PBXs and
with most telephone company switches. One notable exception in
North America is an ATT 5ESS switch, which is provisioned with
Accunet, or an ATT 4ESS switch. For these switches, set the
numbering type to ISDN.
International Dialing Prefix
The international prefix defaults to 011 for North America and 00 for
European countries. The default depends on the country. If you
specify a numbering type or ISDN, the system searches for this
value.

Call-by-Call

Call-by-call is a number from 1 to 31, which is optionally sent to an
upstream telephone company switch, if required. For example,
specify a value of 6 for a T1 PRI network interface module that is
directly connected to an ATT 5ESS switch, which is provisioned with
Accunet. You must consult with the telephone company service
provider to determine whether a call-by-call value is required for a
particular PRI line.
For most cases, the default value of 0 is correct. Always use the
value 0 when connected to a PBX. A non-zero value should not be
required in Europe. Values greater than 31 are reserved for internal
use, and must not be used.
112
Advanced Configuration
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