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Conversions and Transparency
DPNSS
QSIG
Message Waiting
(2)
- Call Back Messaging
- Manufacturer proprietary
signalling
Message Waiting Indication
Remote Registration and
Cancellation of Diversion
- Immediate
- Busy
- No Reply
- Combined
Activate/Deactivate Diversion
- Unconditional
- On Busy
- On No Reply
- All of the above
Where necessary, these service mappings can be enabled and modified individually.
Notes:
(1)
DPNSS PBX routing configurations may need to be modified where the PBX has more
than one interface to the QSIG PBX or network
(2)
There is no explicit message Waiting Indication Service in DPNSS. InterChange iQ 2000
systems support mappings to the standard DPNSS Call Back Messaging service, as used by
Mitel and some Philips PBXs, and to proprietary signalling used by Ericsson, and Siemens
(also Nortel) PBXs. Alternative proprietary signalling extensions can be configured as
necessary.
InterChange iQ 2000 and InterChange iQ 2000plus systems can be configured to support
various QSIG profiles and variants, including ECMA/ETSI (1993), ISO (1995) and ISO-
aligned ETSI (1997), a superset of ISO signalling. These systems do not support ETSI
QSIG segmentation, as this is not required for DPNSS interworking.
5.4 IiQ 2000plus Proxy Interworking Between DPNSS & Q.931
Using its 'proxy' interworking features, InterChange iQ 2000plus can provide a significantly
enhanced level of service beyond the basic Call interworking of InterChange iQ 2000.
The basic Q.931 protocol supported by many PBXs, ISDNs and IP network routers supports
only a limited set of services, whereas DPNSS is service-rich. Thus, when interfacing
DPNSS to a Q.931 network, InterChange is unable to communicate many DPNSS service
requests to the Q.931 equipment. The outcome is that a number of calls, for instance
diversions, cannot be established successfully.
To overcome this, InterChange iQ 2000plus provides a “proxy interworking” feature. When
proxy interworking, IiQ 2000plus acts unilaterally to support DPNSS services on behalf of the
Q.931 equipment. The services that can be supported in this way include Call Forwarding
and most of the significant DPNSS Centralised Operator services.
