M2M IDG500AM-0T001 User Manual page 70

M2M Cellular Gateway
NAT, Data Encapsulation, VPI Number, VCI Number, Schedule Type, Network Monitoring,
IGMP and WAN IP Alias.

RFC 1483 Bridged WAN type: Settings include Data Encapsulation, VPI Number, VCI Number,
Schedule Type, Network Monitoring, IGMP and WAN IP Alias.
There are some common and important configuration parameters common to all WAN Type as
listed below.

Network Monitoring
The gateway supports failover function and the function must depend on the correct decision
when a connection is down. Some parameters are used in the decision process.

DNS Query / ICMP Checking: either one is used to check alive for a WAN connection.

Loading Checking: The response time of replied keep‐alive packets may increase when WAN
bandwidth is fully occupied. To avoid keep‐alive feature work abnormally, enable this option
will stop sending keep‐alive packets when there are continuous incoming and outgoing data
packets passing through WAN connection.

Check Interval: Indicate how often to send keep‐alive packet.

Check Timeout: Set allowance of time period to receive response of keep‐alive packet. If this
gateway doesn't receive response within this time period, this gateway will acknowledge this
keep alive is failed.

Latency Threshold: Set acceptance of response time. This gateway will record this keep‐alive
check is failed if the response time of replied packet is longer than this setting.

Fail Threshold: Times of failed checking. This WAN connection will be recognized as broken if
the times of continuous failed keep‐alive checking equals to this value.

Target1/Target2: Set host that is used for keep alive checking. It can be DNS1, DNS2, default
Gateway, or other host that you need to input IP address manually.
The decision flow chart of keep‐alive checking for a WAN connection is shown as below.
Index skipping is used to reserve slots for new function insertion, when required.
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