VoIP implementation
1. QoS, QoS, QoS
2. Use a separate network if possible, but many not be practical, at the minimum use VLAN, this will help also with security
3. Do Network Assessment periodically - more than once
4. Set correct expectations with users, yes there’s saving, but there’s other inherent issues such as voice quality, etc.
5. Your data network weakness can also become VoIP system weakness (e.g. if your DNS server is down, or router down, etc.)