How does the monthly network transfer pool work?
Network Transfer Quota
Each Linode plan comes with a network transfer quota, which represents the total monthly amount of traffic your services can use. Every plan includes a specified amount of transfer. Transfer quotas are listed for each plan on Linode's pricing page as TB Transfer.
Monthly Network Transfer Pool
In Cloud Manager, you may have noticed a panel on the right side of your Dashboard indicating your Monthly Network Transfer Pool. Your monthly network transfer pool is the total amount of your services' network transfer quota on your account. In other words, the transfer quota provided by all of your Linodes' plans are added together, creating a network transfer pool.
For example, let's say that you have 2 Linodes:
Nanode 1GB - Comes with 1TB transfer
Linode 2GB - Comes with 2TB transfer
Your network transfer pool will reflect the total of 3TB of transfer for that month. If your Nanode 1GB uses 2TB within the month, and Linode 2GB uses .5TB a month, then your total usage will be 2.5TB. Even though you used more transfer than what the Nanode 1GB provides, you will not be charged an overage since you have not exceeded your monthly transfer pool. You will only be charged if you exceed the pool of network transfers, as opposed to exceeding what one plan allows.
What Kind of Traffic Applies?
The transfer quota only considers traffic on your Linodes' public address. Traffic over the private network does not count against your monthly quota. Also, all inbound traffic to your Linodes is free and will not count against your quota. Only outbound traffic through your public address is counted.
Please note: Linode does not offer private IPv6 address allocations. Therefore, the quota will not be affected by local IPv6 traffic; you can use your default IPv6 address as if it were a private IP adddress.
How am I charged?
Your network quota is reset in the beginning of each month. However, your account's transfer quota is prorated based on your Linodes' creation and deletion dates.
A Linode you create mid-month will include a lower transfer amount than what's listed on the pricing page, depending on how much time remains in the month. For example, if a Linode is created halfway through the month, it will come with half of the transfer listed on your Linode's plan. You will see the full transfer amount for the next month.
If you remove a Linode before the end of the month, then you will notice that the network transfer pool will be reduced according to the date the Linode was deleted.
If you use up your monthly network transfer pool, you can continue to use your Linodes normally. That being said, you will be charged $0.01 for each additional GB at the end of your billing cycle.
For more information, please refer to Linode's documention on Network Transfer Quotas.
Difference Between Bandwidth and Network Transfer Quota
Now that I explained what network transfer quota is and how it works, I want to explain bandwidth. In Linode's Pricing Page, you can see that there are specifications titled Gbps Network in and Mbps Network Out, under the network transfer quota. This specification is referred to as the bandwidth. Bandwidth refers to the speeds at which your Linode can communicate over the network. For example, a Nanode 1GB plan provides 40 Gbps Network In, and 1000 Mbps Network Out. This means that your Nanode is capable of 40 Gbps for traffic coming in, and 1000 Mbps for traffic going out. This limit applies to both private and public connections.
Depending on what your traffic looks like (size of packets, quantity of packets), you may see some packet loss regardless of whether you hit that limit or not.