Cisco VG30D, Руководство пользователя

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6-2
Cisco VG30D Voice Gateway User Guide
OL-19276-01
Chapter 6 Conversions and Transparency
Q.931/DPNSS Conversion Configuration
DPNSS Networks in the UK typically support overlap signalling for all calls. You can make the Cisco
VG30D Voice Gateway block up incoming digits from DPNSS by setting this option to
None or
I ncoming . In isolated cases, it may be appropriate to turn on preemptive call forwarding in the Q.931
stack. This action very rarely is required. However, if it is needed, it operates as described in DPNSS
Port 2 Configuration .
If the En-bloc Call Forwarding Timeout in Advanced Configuration is set to 0 , the normal Q.931 T302
timer runs to clear incomplete calls after 15 seconds without dialling activity.
Advanced Configuration
Q.931 Profile Selection
You can profile the Q.931 port to conform to ETSI, AT&T (TR 41449), Euro-ISDN or QSIG definitions.
The default is QSIG.
For DPNSS/QSIG transparency the Layer 3 protocol Profile must get set to QSIG .
The ETSI profile is based on ETSI Specification ETS 300 102-1,). The Euro-ISDN profile is based on
the same specification, with amendments applied in ETSI specification ETS 300 102-1/A2. The
differences between the ETSI and Euro-ISDN profiles relate to the content of messages. No changes
occur to call setup and clear-down.
Cisco Systems, Inc., recommends that Euro-ISDN profile be used when you are not configuring the
Cisco VG30D Voice Gateway for transparency, irrespective of a requirement for TBR-4 compliancy.
Choose the ETSI profile only where TBR-4 compliancy is not required and where the Euro-ISDN profile
is deemed to be incorrect. Where TBR-4 compliance is required, you must choose the Euro-ISDN
profile.
Each profile sets particular defaults, appropriate to the standard definition, but these values can then be
overridden by specific action, which allows customisation of the interface to non-standard equipment
implementations. The rest of this section discusses these override options.
Services Configuration
Default Destination Address
When you are operating into a DPNSS-based public network, which may address to the subscriber
number only with no private network extension number, you must ensure that a private network
extension number is supplied. This enables non-DDI calls to get directed to a sensible destination such
as the common operator. Normally, this would occur in the Q.931 PBX. However, in Cisco VG30D Voice
Gateway AT&T and QSIG implementations, it can get configured to be supplied by the Converter.
By default, non-DDI calls get a Q.931/QSIG Called Party Address of 0 as the ubiquitous operator
number. You can customize this forwarding address by configuring the appropriate private network
number, including any node address, as the Default Destination Address.
You do not need the Default Destination Address for transparency.