Business case for direct connect vs VPN

Hello,

My customer is starting with AWS and is running a few workloads on our cloud already. They are looking at interconnecting their data centers with AWS and we presented the different options VPN vs Direct Connect. This is what we shared to compare both:

VPN:

• Over the Internet
• Easy to install, set up in minutes
• Bandwidth: 1 VPN tunnel = 1.25 Gbps
• Encryption: Encrypted in transit
• Cost: Charged per hour per VPN connection + data transfer (0.9€/GB)

Direct connect:

• Physical, dedicated connection (not using the internet) = consistent performance, reduced bandwidth costs
• Some set-up time required –can be few days
• Bandwidth: Direct Connect Connection = 50 Mbps–10Gbps
• Encryption: Not encrypted in transit but can be combined with VPN to have encryption
• Cost: Charged per port hour + data transfer (0.2€/GB)

We also said that a VPN is good to start or when the cloud is only used for test and development but that a direct connect is better in case they want to migrate applications to the cloud, use split-tier architecture or want to use our cloud as disaster site for example. Data transfer costs are also lower with direct connect so in case they are transferring a lot of data, a direct connect might be cheaper.

My questions are:

• Is there a white paper or another document comparing direct connect vs vpn that I could share with the customer ?
• Do we have a list of use cases requiring direct connect that my customer could use to justify a direct connect?
• Do we have a business case for direct connect vs VPN? I mean can direct connect becomes cheaper than VPN if there is a lot of data transfer for example.

Thanks for your help