User`s guide

33(59)
Datum/Date Rev
Dokumentnr/DocumentnrUppgjord/Prepared
Dokansv/Godkänd - Doc respons/Approved Kontr/Checked Tillhör/Referens-File/Reference
99-07-15 A
365/155 34-ASB 150 02 Uen
FACILITY DESCRIPTION
Faktaansvarig - Subject responsible
Proprietary service -
Called party number transfer via UUS1
Definition
In some countries it is required that the DDI numbers
used for automatic incoming calls to extensions within
a PBX are subscribed to the public network. In order to
reduce the number of subscriptions as well as the
resulting subscription costs, especially for trunks
reserved for CN VPN traffic, it is possible to use the
feature “Called party number transfer via UUS1”.
Use
When using this feature, only one number - the
national significant number to reach the PBX - has to
be subscribed to the public network. The DDI numbers
for reaching extensions within the system will be sent
as embedded proprietary information between the CN
PBXs.
Operation
In order to send the DDI numbers as proprietary
information, the called CN party number sent between
the PBXs has to be split into two parts:
• The most significant part of the number ( national
destination code + subscriber number without
extension number ) will be sent in the call set-up
message as called party number IE. This
number is used to reach the destination PBX.
• The least significant part of the number ( B-par-
ty’s extension number part ) will be sent as a pro-
prietary called number IE in the UUI between the
CN PBXs in the network. To be able to transfer
the information, the UUS 1 service is required .
Due to the fact that the extension numbers are
embedded as proprietary UUI in the call set-up
message, they are not transparent to the public
network and do not have to be subscribed.
Furthermore, the called number’s digits in the UUI can
be more than only a ‘B-party extension number’; thus a
call may continue as gateway/transit call set- up to
another network after the CN PBX which was first
addressed has been reached.
At incoming proprietary CN calls, the called number
received from the UUI will be treated as “extended”
number part of the received information of the called
party number IE . On the trunk line used both types of
digits will be combined and stored for further number
analysis in order to continue with an internal call set-up
or in case of a gateway/transit call to set-up a new CN
call.
To guarantee the feature functionality, both calling and
called PBX must support the feature.
• A continued gateway/transit call set-up may fur-
ther use this feature or continue as an ordinary
call set-up, depending on the parameter settings
at the outgoing side (PNR) and the interworking
network.
Both T and Q reference points, where the UUS1
service is available, can be used to carry the re-
lated information.
• Which of the dialled digits will be sent as called
party number IE and/or as proprietary called
number IE in the UUI will be defined in the PNR
for each route choice by the number length con-
trol parameters. (Complete called party number
length and Subscriber called party number
length ).