AudioCodes Mediant 3000 User Manual page 512

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SIP OPTIONS: The device sends "keep-alive" SIP OPTIONS messages to the IP
destination. If the device receives a SIP 200 OK in response, it considers the
destination as available. If the destination does not respond to the OPTIONS
message, then it is considered unavailable. You can configure the time interval
for sending these OPTIONS messages, using the 'Alt Routing Tel to IP Keep
Alive Time' parameter.
These parameters are configured in the Routing General Parameters page
(Configuration tab > VoIP menu > Gateway > Routing > General Parameters), as
shown below:
Figure 25-6: IP Connectivity Method in Routing General Parameters Page

Quality of Service (QoS): You can enable the device to check the QoS of IP
destinations. The device measures the QoS according to RTCP statistics of previously
established calls with the IP destination. The RTCP includes packet delay (in
milliseconds) and packet loss (in percentage). If these measured statistics exceed a
user-defined threshold, the destination is considered unavailable. Note that if call
statistics is not received within two minutes, the QoS data is reset. These thresholds
are configured using the following parameters:
•
'Max Allowed Packet Loss for Alt Routing' (IPConnQoSMaxAllowedPL): defines
the threshold value for packet loss after which the IP destination is considered
unavailable.
•
'Max Allowed Delay for Alt Routing' (IPConnQoSMaxAllowedDelay): defines the
threshold value for packet delay after which the IP destination is considered
unavailable
These parameters are configured in the Routing General Parameters page, as shown
below:
Figure 25-7: IP QoS Thresholds in Routing General Parameters Page

DNS Resolution: When a host name (FQDN) is used (instead of an IP address) for
the IP destination, it is resolved into an IP address by a DNS server. The device
checks network connectivity and QoS of the resolved IP address. If the DNS host
name is unresolved, the device considers the connectivity of the IP destination as
unavailable.
You can view the connectivity status of IP destinations in the following Web interface
pages:

Tel-to-IP Routing table: The connectivity status of the IP destination per routing rule
is displayed in the 'Status' column. For more information, see ''Configuring Tel-to-IP
Routing Rules'' on page 496.

IP Connectivity: This page displays a more informative connectivity status of the IP
destinations used in Tel-to-IP routing rules in the Tel-to-IP Routing table. For viewing
this page, see ''Viewing IP Connectivity'' on page 754.
User's Manual 512
Mediant 3000
Document #: LTRT-89730