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Version 6.6 633 October 2014
Installation & Operation Manual 40. General SIP Configuration
Table 40-21: NAT Translation Parameters
Parameter
Name
Type
Provisioning
Type
Description
Global IP Start
Port Integer
1-65535 Online Optional port range (1-65535) of the global
address. If no ports are required, leave this
field blank.
Global IP End
Port Integer
1-65535 Online Optional port range (1-65535) of the global
address. If no ports are required, leave this
field blank.
40.13 Least Cost Routing (LCR) Table
The LCR feature enables the device to choose the outbound IP destination routing
rule based on lowest call cost. This is useful in that it enables service providers to
optimize routing costs for customers. For example, you may wish to define different
call costs for local and international calls, or different call costs for weekends and
weekdays (specifying even the time of call). The device sends the calculated cost of
the call to a Syslog server (as Information messages), thereby enabling billing by third-
party vendors.
LCR is implemented by defining Cost Groups and assigning them to routing rules in
the Outbound IP Routing table. The device searches this routing table for matching
routing rules, and then selects the rule with the lowest call cost. If two routing rules
have identical costs, then the rule appearing higher up in the table is used (i.e., first-
matched rule). If a selected route is unavailable, the device selects the next least-cost
routing rule. However, even if a matched rule is not assigned a Cost Group, the device
can select it as the preferred route over other matched rules with Cost Groups. This is
determined according to the settings of the Default Cost parameter in the Routing
Rule Groups table.
The Cost Group defines a fixed connection cost ( connection cost ) and a charge per
minute ( minute cost ). Cost Groups can also be configured with time segments ( time
bands ), which define connection cost and minute cost based on specific days of the
week and time of day (e.g., from Saturday through Sunday, between 6:00 and 18:00).
If multiple time bands are configured per Cost Group and a call spans multiple time
bands, the call cost is calculated using only the time band in which the call was initially
established.
In addition to Cost Groups, the device can calculate the call cost using an optional,
user-defined average call duration value. The logic in using this option is that a Cost
Group may be cheap if the call duration is short, but due to its high minute cost, may
prove very expensive if the duration is lengthy. Thus, together with Cost Groups, the
device can use this option to determine least cost routing. The device calculates the
Cost Group call cost as follows: Total Call Cost = Connection Cost + (Minute Cost *
Average Call Duration).