AWSAWS Direct ConnectNetworking & Content Delivery

`aws_directconnect_lag` cost estimation

A Link Aggregation Group that bundles multiple Direct Connect connections into one logical link. The LAG object is free. Each member connection bills per port-hour, from about $0.30/hour for 1 Gbps to $22.50/hour for 100 Gbps, plus data transfer out.

The aws_directconnect_lag resource bundles two or more dedicated Direct Connect connections into a single logical, higher-bandwidth link with failover. The LAG object itself is free. AWS does not charge for the aggregation construct. What it bills for is the member connections inside it, and those are among the more expensive networking line items on AWS.

Each dedicated connection in a LAG bills per port-hour by speed. In US regions that is roughly $0.30/port-hour for 1 Gbps (about $219/month), $2.25/port-hour for 10 Gbps (about $1,642/month), and $22.50/port-hour for 100 Gbps (about $16,425/month). A LAG must contain connections of the same speed, and every member port bills independently. So a LAG of two 10 Gbps connections for redundancy is two ports, roughly $3,284/month in port charges alone, whether or not you push traffic across both. The whole point of a LAG is redundancy and aggregate bandwidth, and you pay for each physical port that provides it.

Data transfer is the second meter and it is easy to underestimate. Direct Connect data transfer out is billed per GB by the connection location and the AWS region it reaches, commonly around $0.02/GB in US locations, which is much cheaper than internet egress but not free. Data transfer in is free. On a high-throughput link, egress can rival or exceed the port-hour cost: 100 TB of monthly egress at $0.02/GB is $2,000. There is no charge for data transfer over Direct Connect that stays within the same AWS Region to a VPC, but cross-region and internet-bound traffic still bills.

A gotcha: LAG ports keep billing even when the link is down or unused, because you are renting the physical port at the colocation facility. A LAG provisioned for a migration and then forgotten quietly bills thousands per month. Also, hosted connections (ordered through a partner) have a different, often lower, pricing model than dedicated connections and cannot always be placed in a LAG. Right-sizing the number and speed of member ports to actual redundancy and throughput needs is the main lever.

c3x flags aws_directconnect_lag as free and attributes port-hour and data-transfer cost to the member connections it bundles.

Terraform example

A minimal but realistic configuration that C3X can estimate.

resource "aws_dx_lag" "primary" {
  name                  = "prod-dx-lag"
  connections_bandwidth = "10Gbps"
  location              = "EqDC2"
  force_destroy         = false
}

resource "aws_dx_connection" "member_a" {
  name      = "prod-dx-a"
  bandwidth = "10Gbps"
  location  = "EqDC2"
  lag_id    = aws_dx_lag.primary.id
}

resource "aws_dx_connection" "member_b" {
  name      = "prod-dx-b"
  bandwidth = "10Gbps"
  location  = "EqDC2"
  lag_id    = aws_dx_lag.primary.id
}

Pricing dimensions

What you actually pay for when you provision aws_directconnect_lag.

Dimension	Unit	What's being charged
LAG object	free	The Link Aggregation Group construct that bundles connections carries no AWS charge. $0 (free)
Member port (1 Gbps)	per hour	Each dedicated 1 Gbps connection in the LAG bills per port-hour regardless of traffic. About $0.30/port-hour (~$219/month) in US locations
Member port (10 Gbps)	per hour	Each 10 Gbps connection port, billed independently and multiplied by member count. About $2.25/port-hour (~$1,642/month) in US locations
Data transfer out	per GB	Egress over Direct Connect billed by location and destination region. Data transfer in is free. About $0.02/GB in US locations

Optimization tips

Common ways to reduce aws_directconnect_lag cost without changing the workload.

Right-size port speed and count to real throughput

$1,642/month per removed 10 Gbps port

Every member port bills 24/7 whether or not it carries traffic. Provision the aggregate bandwidth you actually use plus the redundancy you need, rather than defaulting to more or faster ports than the workload requires.

Decommission LAGs left over from migrations

Thousands per month per forgotten LAG

A LAG stood up for a data migration or cutover keeps billing per port until the connections are deleted. Audit Direct Connect for idle LAGs and tear down ports you no longer route traffic across.

Prefer Direct Connect egress over internet egress for steady traffic

Roughly $0.07/GB versus internet egress

Direct Connect data transfer out (around $0.02/GB) is far cheaper than internet egress (around $0.09/GB). For high, steady outbound volume, routing it over the LAG rather than the internet gateway cuts per-GB cost substantially.

Consider hosted connections for lower bandwidth needs

If you do not need dedicated 1 Gbps or more, a hosted connection ordered through a Direct Connect partner can start at lower speeds and cost than a dedicated port. Match the connection type to the bandwidth you actually need.

FAQ

Does a Direct Connect LAG cost anything by itself?

No. The LAG is a free logical construct. You pay for the dedicated connections inside it, each billed per port-hour by speed, plus data transfer out over the link. The LAG just aggregates those billed ports into one logical, redundant connection.

How much does a redundant 10 Gbps LAG cost?

A LAG with two 10 Gbps member connections is roughly $2.25 per port-hour each, about $3,284/month in port charges combined, before any data transfer. Every port bills independently and continuously, so redundancy doubles the port cost by design.

Do I pay for a LAG port even when it is idle?

Yes. Port-hour charges accrue as long as the physical port is provisioned at the colocation facility, regardless of whether the link is up or carrying traffic. Idle LAGs left after a migration are a common source of large, forgotten bills.

Is data over Direct Connect free?

Data transfer in is free. Data transfer out bills per GB by location and destination region, commonly around $0.02/GB in US locations, which is much cheaper than internet egress but still meaningful at high volume. Traffic that stays within the same region to a VPC generally is not charged for transfer.