AudioCodes Mediapack mp-11x, Руководство пользователя

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SIP User's Manual 130 Document #: LTRT-65409
MediaPack Series
„ Alternative Routing (when Proxy isn't used): an alternative IP destination for telephone
number prefixes is available. To associate an alternative IP address to called
telephone number prefix, assign it with an additional entry (with a different IP
address), or use an FQDN that resolves to two IP addresses. The call is sent to the
alternative destination when one of the following occurs:
•
No ping to the initial destination is available, or when poor QoS (delay or packet
loss, calculated according to previous calls) is detected, or when a DNS host
name is not resolved. For detailed information on Alternative Routing, refer to
'Configuring Alternative Routing (Based on Connectivity and QoS)' on page
342 .
•
When a release reason that is defined in the 'Reasons for Alternative Tel to IP
Routing' table is received. For detailed information on the 'Reasons for Alternative
Routing Tables', refer to 'Reasons for Alternative Routing' on page
136 .
Alternative routing (using this table) is commonly implemented when there is no response
to an INVITE message (after INVITE retransmissions). The gateway then issues an internal
408 'No Response' implicit release reason. If this reason is included in the 'Reasons for
Alternative Routing' table, the gateway immediately initiates a call to the redundant
destination using the next matched entry in the 'Tel to IP Routing' table. Note that if a
domain name in this table is resolved to two IP addresses, the timeout for INVITE
retransmissions can be reduced by using the parameter 'Number of RTX Before Hotswap'.
Note:
If the alternative routing destination is the gateway itself, the call can be
configured to be routed back to PSTN. This feature is referred to as 'PSTN
Fallback', meaning that if sufficient voice quality is not available over the IP
network, the call is routed through the legacy telephony system (PSTN).
Tip:
Tel-to-IP routing can be performed either before or after applying the number
manipulation rules. To control when number manipulation is performed, set
the Tel to IP Routing Mode (or RouteModeTel2IP
ini
file) parameter
(described in the table below).
You can also configure the Tel to IP Routing table using the
ini
file parameter Prefix (refer
to 'Number Manipulation and Routing Parameters' on page 304 ).
¾
To configure the Tel to IP Routing table, take these 6 steps:
1.
Open the 'Tel to IP Routing' screen (
Protocol Management
menu >
Routing Tables
submenu >
Tel to IP Routing
option).