Least Cost Routing; Overview - AudioCodes Mediant 4000 SBC User Manual

CHAPTER 16 Services
■ Rule 1: Sends call to private telephone line (at 10.33.45.60) upon successful AD query result
for the private attribute.
■ Rule 2: Sends call to IP PBX (at 10.33.45.65) upon successful AD query result for the PBX
attribute.
■ Rule 3: Sends call to Skype for Business client (i.e., Mediation Server at 10.33.45.68) upon
successful AD query result for the Skype for Business attribute.
■ Rule 4: Sends call to user's mobile phone number (to PSTN through the device's IP address at
10.33.45.100) upon successful AD query result for the Mobile attribute.
■ Rule 5: Sends call to IP address of device (10.33.45.80) if AD query failure (e.g., no response
from LDAP server or attribute not found).
■ Rule 6: Sends query for original destination number of received call to the LDAP server.
■ Rule 7: Alternative routing rule that sends the call of original dialed number to IP destination
10.33.45.72. This rule is applied in any of the following cases
● LDAP functionality is disabled.
● LDAP query is successful but call fails (due to, for example, busy line) to all the relevant
attribute destinations (private, Skype for Business, PBX, and mobile), and a relevant SBC
Alternative Routing Reason (see
Reasons) has been configured.
Once the device receives the original incoming call, the first rule that it uses is Rule 6, which
queries the AD server. When the AD replies, the device searches the table, from the first rule down,
for the matching destination phone prefix (i.e., "PRIVATE:, "PBX:", "OCS:", "MOBILE:", and
"LDAP_ERR:"), and then sends the call to the appropriate destination.

Least Cost Routing

This section describes the device's Least Cost Routing (LCR) feature.

Overview

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 IP-to-IP
Routing table (for SBC calls). The device searches the routing table for matching routing rules and
then selects the rule with the lowest call cost. If two routing rules have identical costs, the rule
appearing higher up in the table is used (i.e., first-matched rule). If the selected route is unavailable,
the device selects the next least-cost routing rule.
Even if a matched routing rule is not assigned a Cost Group, the device can select it as the
preferred route over other matched rules that are assigned Cost Groups. This is determined
according to the settings of the 'Default Call Cost' parameter configured for the Routing Policy
(associated with the routing rule for SBC calls). To configure the Routing Policy,; for SBC calls,
see Configuring SBC Routing Policy
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.
Configuring SIP Response Codes for Alternative Routing
Rules.
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Mediant 4000 SBC | User's Manual