Cloud dedicated lines: what they solve and when to skip them

After moving to the cloud, the first problem is rarely compute capacity — it is unstable connectivity between on-premises and cloud. Public internet plus IPSec VPN works, but jitter is high, troubleshooting is hard and throughput depends on internet quality. Cloud dedicated lines are designed for exactly this.

1. Three things it solves

• Controllable path: a dedicated circuit from your site to the cloud provider's access point, bypassing congested international gateways.
• Committed bandwidth: purchase 10 Mbps to 10 Gbps of dedicated capacity rather than competing with public traffic.
• Fixed source IP: security groups can allowlist a stable IP, more dependable than dynamic public addressing.

2. When it is worth it

Usually worth it:

• Core databases in the cloud, read and written frequently by on-premises applications
• Active-active or disaster recovery replication between site and cloud
• Multi-cloud architecture requiring connectivity between providers
• Compliance requirements to keep data off the public internet

Usually not:

• Only small management traffic, such as occasional SSH
• Latency-insensitive workloads like offline batch processing or archival backup
• Very tight budgets where occasional jitter is acceptable

3. How to size bandwidth

Do not size on total office bandwidth. Size on actual site-to-cloud interaction:

• Database replication: daily delta and peak write rate
• Object storage: peak concurrent download, including bursts
• Backup links: average rate within the backup window

Plan for 1.5× peak to absorb bursts.

4. Common misuse

Routing all internet traffic through the cloud line. A cloud dedicated line is built for private cloud networks, not as a replacement for the office internet egress. Pushing staff browsing through it wastes capacity and competes with business traffic.

A single line with no redundancy. Dedicated lines fail too — fibre cuts, access equipment faults. Critical workloads need primary and backup, or dedicated line plus VPN backup.

Ignoring route design. Without planning VPC route tables, local egress and BGP advertisements, you get the classic "ping works but the application does not".