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VoIP gateway IP400 version 5.01
5.2.7 Dealing with the various ISDN address types
Call numbers are always treated internally by the gateway as
unknown
type of
number
. In ISDN however, there are various types of call numbers (see Table 8)
with the effect that call numbers are only ever interpreted in combination with
their number types. On an exchange line in Germany for example a call number
0711654321
with the type of number
unknown
corresponds to the call number
711654321
with the type of number
national
. This is due to the fact that in
Germany the code for national numbers is
0
. On the other hand the call number
41551234
with the number type
unknown
refers to a connection within one's
own local network, whereas the same number
41551234
with a number type
international
refers to a connection in the local network of Pfäffikon in Switzer-
land.
The call number type unknown therefore has to be standardised in order to eval-
uate call numbers within the gateway. This can be done with the help of entries
in the so-called
CGPN (calling party number) map
and
CDPN (c
alle
d
p
arty
n
umber)
map
, which can be defined both on the ISDN interfaces, and in the indi-
vidual gateway definitions.
Name
Description
Typical use
Abbre-
via-
tion
1
Code
2
Unknown
Unspecified
Number called
in outgoing call.
u
Subscriber
Call number in
local network.
Number called
in incoming call.
s
National
Call number with
area code
Calling number
from home
country.
n
0
Interna-
tional
Call number with
country code and
area code.
Calling number
from abroad.
i
00
Abbreviated
Unusual
a