ACA High Availability & Redundancy 3

Question 1

What is 'Geographic Redundancy' in AudioCodes deployments, and how does it differ from local HA?

Accepted Answer

Geographic redundancy places units at separate physical sites for disaster recovery; local HA places both units in the same rack

Answer

Geographic redundancy uses DNS SRV records to distribute calls; local HA uses VRRP

Answer

Geographic redundancy requires separate SIP trunks; local HA shares a single trunk between both units

Answer

Geographic redundancy is only supported on software-based SBCs; local HA requires hardware appliances

Question 2

How does AudioCodes handle PSTN/TDM trunk state during an HA failover event?

Accepted Answer

The standby unit has pre-configured identical trunk parameters and reconnects trunks automatically after taking the active role

Answer

All PSTN channels are dropped and must be re-established by the PSTN carrier after switchover

Answer

PSTN trunks are temporarily bridged between active and standby using a shared TDM bus

Answer

PSTN traffic is rerouted to a third backup gateway until the HA pair recovers

Question 3

What AudioCodes tool is used to monitor the health and status of an HA pair in real time?

Accepted Answer

AudioCodes One Voice Operations Center (OVOC) or the device's built-in Web Management Interface

Answer

AudioCodes Configuration Wizard within the Web GUI

Answer

AudioCodes License Manager portal at AudioCodes.com

Answer

The SIP Ladder Diagram tool in the Syslog viewer

Question 4

Which parameter in the AudioCodes HA configuration defines how long the standby unit waits before declaring the active unit failed and initiating switchover?

Accepted Answer

HA Keep-Alive Loss Threshold (number of missed keep-alives before failover)

Answer

SIP Session Timer (Session-Expires header value)

Answer

RTCP monitoring interval for media quality detection

Answer

TCP retransmission timeout for SIP signaling links

Question 5

In AudioCodes HA, what is the implication of a 'Split-Brain' scenario?

Accepted Answer

Both the active and standby units simultaneously believe they are the active unit, causing IP conflicts and call handling issues

Answer

The HA link becomes overloaded, causing configuration sync to lag behind real-time call state

Answer

The standby unit reverts to factory defaults because it cannot reach the active unit

Answer

SIP registrations are split evenly between active and standby units for load balancing

Question 6

What is the function of the 'HA Network Monitoring' feature in AudioCodes devices?

Accepted Answer

It watches critical network interfaces and triggers failover if a monitored link goes down on the active unit

Answer

It monitors SIP trunk quality metrics and triggers failover if MOS drops below 3.5

Answer

It sends periodic reports to OVOC summarizing HA switchover history

Answer

It verifies that DNS resolution for SIP servers is consistent between both units

Question 7

After an AudioCodes HA failover where the originally-active unit recovers, what is the default behavior?

Accepted Answer

The recovered unit rejoins as the standby unit and does not automatically reclaim the active role

Answer

The recovered unit immediately reclaims the active role (automatic revert)

Answer

Both units enter a negotiation period where the one with higher uptime becomes active

Answer

The recovered unit requires a manual reboot before it can participate in the HA pair again