How to run VICIdial on Linode/Akamai

Linode, now operating under the Akamai Cloud brand, has been a Linux-friendly VPS provider for many years. It is a dependable choice for running a VICIdial contact center server: the control panel is clean, the Dedicated CPU plans give you guaranteed compute (not shared vCPUs), and the global footprint is solid. Getting the networking and firewall settings right is the part that demands attention.

This guide covers the Linode-specific decisions. For the broader cloud-hosting strategy, read running VICIdial in the cloud first.

Shared CPU vs. Dedicated CPU plans

Linode's Shared CPU plans (the standard tier) burst well for short tasks, but VICIdial hammers MySQL continuously during a dialing campaign. Under CPU contention on a shared host, the keepalive processes that monitor active calls can fall behind, leading to phantom calls and dropped sessions. For anything more than a small test center, choose a Dedicated CPU plan. You get full-core allocation, which prevents the keepalive lag that causes problems in predictive dialing (Predictive dialing, the mode that calls ahead of available agents to minimize wait time).

A 4-vCPU Dedicated instance with 8 GB handles up to about 25-30 concurrent calls (Concurrent calls, the count of active voice channels at any moment). Add agents cautiously and monitor MySQL slow-query logs before scaling hardware.

Cloud Firewall configuration for SIP and RTP

Linode's Cloud Firewall is a stateful network-layer firewall that you attach to Linodes from the control panel. It defaults to accepting all inbound traffic, but you should lock it down and only allow what VICIdial needs. SIP (SIP (Session Initiation Protocol), the protocol that sets up and terminates calls) runs on UDP and TCP port 5060. RTP (RTP, the real-time transport stream carrying voice samples) needs a wide UDP range, typically 10000-20000.

stateDiagram-v2
    [*] --> FirewallAttached
    FirewallAttached --> SIPOpen: add port 5060 rule
    SIPOpen --> RTPOpen: add UDP 10000-20000 rule
    RTPOpen --> SSHRestricted: limit port 22 to admin IP
    SSHRestricted --> ReadyToDial: ufw enabled on instance
    ReadyToDial --> [*]

# Linode Cloud Firewall inbound rules:
# Accept TCP/UDP 5060   All IPv4/IPv6   (SIP)
# Accept UDP 10000-20000 All IPv4/IPv6  (RTP media)
# Accept TCP 443        All IPv4/IPv6   (HTTPS)
# Accept TCP 22         Admin IP only   (SSH)
# Drop all other inbound

# Instance ufw:
ufw default deny incoming
ufw allow 5060
ufw allow 10000:20000/udp
ufw allow 443/tcp
ufw enable

IP addressing and Asterisk NAT settings

Linode instances get a direct public IPv4 and an optional private address for internal traffic. The public interface is directly routed — no SNAT between your instance and the internet. This means NAT traversal (NAT traversal, the configuration that rewrites SDP contact addresses so the remote party can reach you) is not required for standard deployments. Set externip in your Asterisk SIP config to the instance's public IPv4 and set localnet to the private subnet if you use the VLAN feature.

Linode does not offer a built-in reserved/floating IP the way some providers do. If you need IP stability across rebuilds — for example because your carrier uses IP authentication (IP authentication, where the carrier allows calls only from a pre-approved IP address and requires no SIP password) — document your IP and plan to update the carrier allowlist after any rebuild.

Block storage for recordings

Linode Block Storage volumes are persistent and detachable. Attach one at provisioning time and mount it at /var/spool/asterisk/monitor. Call recordings (Call recording) will survive any Linode rebuild if the volume stays attached separately. Linode Object Storage (S3-compatible) makes a good archive target for recordings older than 30 days.

For more detail on firewall management across cloud providers, see VICIdial cloud firewall management.

Installing VICIdial and what to expect

The Linode Marketplace has no VICIdial entry. You provision an Ubuntu 22.04 Linode, run the VICIdial install scripts, configure your SIP trunk (SIP trunk, the SIP channel between your Asterisk instance and your carrier), and tune the system. The process takes the better part of a day the first time. After installation, take a Linode snapshot so you have a clean restore point if something goes wrong.

If you would rather your dialer be ready in under 40 seconds instead of a day, VICIfast managed plans handle the full install, hardening, and configuration. You bring your carrier and leads; the server is ready to dial.