Cisco VG30D, Руководство пользователя

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4-9
Cisco VG30D Voice Gateway User Guide
OL-19276-01
Chapter 4 Management and Configuration
Q.931 Configuration
•
Support ECMA Progress Description Codes : Checking this box will allow the Cisco VG30D
Voice Gateway to process ECMA progress description codes in addition to the default ITU-T codes.
• Change Status Element Supported : Checking this box enables the Cisco VG30D Voice Gateway
to process Change Status Information elements.
•
Channel Preference for Outgoing Calls : This setting controls the encoding of the outgoing
Channel Id Information Element and the behaviour of the Cisco VG30D Voice Gateway when
requested channels are unavailable. Set to
Preferred if you are using switched channel mapping.
Otherwise, use Exclusive .
•
Incoming Channel Mapping : If this setting is configured to Fixed , the channel that is used by the
incoming call must be used for the outgoing call. If this setting is configured to Switched , a different
channel may be used in the outgoing Q.931 call, and the Cisco VG30D Voice Gateway will switch
the bearer channel internally.
• B-channels Initial State : This setting sets the initial state of each channel to either Free (and
in-service) or Out of Service .
•
Response to Status Enquiry in Null-State : This setting sets the response of the Cisco VG30D
Voice Gateway to an incoming Status Enquiry message received when the call is in the NULL state.
The Cisco VG30D Voice Gateway may respond by sending either a Release Complete message or a
Status message.
•
Response to Status Enq. with Global Call Ref : This setting sets the response of the Cisco VG30D
Voice Gateway to an incoming Status Enquiry message with the Global call Reference. The Cisco
VG30D Voice Gateway may be configured to
Always Null and ignore the message or Send Status
to send the message.
• Send Status to Errored Optional Elements : This setting dictates whether the Cisco VG30D Voice
Gateway should send a Status message in response to a message that contains an errored Information
Element. If it sends the status message, this setting dictates whether it should be the call status
Before Processing or After Processing the received message.
•
Clear Forward if No Response to Setup : This parameter allows the Cisco VG30D Voice Gateway
behaviour on expiry of the Q.931 T303 timer to be specified. The Cisco VG30D Voice Gateway may
be configured to
Always send Release Complete forward, Never send it, or send when configured
as the Network end only .
•
Symmetrical Call State : When this setting is checked, call state reported in Status messages will
be QSIG. Otherwise, the Cisco VG30D Voice Gateway will report Q.931 user or Network end state
dependent on configuration.
• En-bloc Call Forward Digit Count : Overlap dialed Q.931/QSIG calls can be turned into en-bloc
calls. When the specified number of digits has been received, the call gets forwarded en-bloc. This
is only appropriate for networks with fixed-length dial plans.
•
En-bloc Call Forward Timeout : This setting acts as an interdigit timer that will forward the call
when it expires. It gets restarted as each digit arrives. This setting proves suitable for networks with
variable-length dial plans but introduces a post dial delay.
Q.931 Services
Configuration options include the following:
• Enable Call Independent Signalling : This option allows the Cisco VG30D Voice Gateway to
process non-bearer-related signalling necessary for supplementary services operation.