Cucm Hardware Requirements Jun 2026

Give subscribers more resources if call volume is high. Keep publishers lean but stable.

💡 Disk latency is the silent killer of CUCM clusters. If your storage cannot keep up with database replication, the cluster will become "out of sync," leading to administration failures and call processing issues. Network Interface Cards (NIC) 1 Gbps or 10 Gbps Ethernet interfaces are required. VMware vSwitch must be configured to prevent packet loss. Planning for High Availability (HA) cucm hardware requirements

Deploy using the OVA for the next major version you might upgrade to, or at least one size larger than current needs. You can scale down later if needed (though scaling up requires a reboot). Give subscribers more resources if call volume is high