EC2 Instance with limited single connection speed

Question

Hello Everyone,

I hope to provide as much info as needed to resolve this issue. The problem is that we need to move a large amount of data from AWS to our in house server. We have been running some tests using a Windows 2022 m4.2xlarge instance (AWS) to a Windows 2022 Dell m640 *(in house). The in house server is non-virtualized and has a 1Gb/s dedicated internet connection that is not being utilized by anything else.  However, the single file transfer speed between AWS and our in house server seems to be capped at 25Mb/s. I can run 20 simultaneous file transfers and the overall bandwidth stabilizes around 500Mb/s.  I have tested this using iperf3, FTP, and IIS. All seem to suffer from the same low bandwidth issue when it comes to a single file being transferred. However, FTP was slightly faster at around 80Mb/s and I am assuming that is due to using multiple treads to move the data.

I have tested each server using www.speedtest.net. From AWS I choose my ISP's testing server that is located in the same datacenter as our inhouse server and recieved of 614Mb/s down and 827Mb/s up. The in house server was also tested using several test servers located in the same state where our AWS instance resides. Those test averaged around 400Mb/s down and 400Mb/s up.

I have researched this quite a bit, however I cannot find the cause. Any help would be appreciated.

Oleksii Bebych · Answer

EC2 network performance depends on the instance type.
https://aws.amazon.com/ec2/instance-types/

![Enter image description here](/media/postImages/original/IMp4otdLtVSK2Nv-r7NkccLg)

This has different values (Low, Moderate, High, Up to 5 Gbps, 10 Gigabit, 25 Gigabit, etc.)

Low, Moderate, High are not static values and may depend on AWS Region and Time

Some tests for US-EAST-1 showed that LOW corresponds to 50Mb/s, Moderate corresponds to 300Mb/s and High corresponds to 1Gb/s.

You can also try the newer instance type m5.2xlarge which has "Up to 10 Gb" and is a bit cheaper

```
m4.2xlarge	$0.40
m5.2xlarge	$0.384
```

![Enter image description here](/media/postImages/original/IMzMyz7w9aREOodMZUvTg43g)

Justin · Answer

Thank you for the response however, I do not believe changing the instance type would have the desired effect. Originally our AWS test instance was a t3a.small Windows 2022 (low to moderate network performance). We saw almost identical results when testing the bandwidth of a single transfer - 25Mb/s. Multiple simultaneous transfers capped out around 400Mb/s. So there was a slight improvement for multiple simultaneous transfers by upgrading to a m4.2xlarge. The current m4.2xlarge instance has the needed bandwidth to our local ISP (614Mb/s down and 827Mb/s up). However, the bandwidth used for a single file transfer (25Mb/s) is the limiting factor. Our goal is to be able to transfer our large files at 300Mb/s or better. The m4.2xlarge instance type should be able to handle that.

To me it looks like there is a traffic shaping policy in place. iperf3 Results Bandwidth usage on AWS instance

I conducted these tests from several independent locations including my personal desktop. All with almost identical results. Therefore any traffic shaping polices that cloud affect the bandwidth of a single file transfer are not on our side.

To me it looks like there is a traffic shaping policy in place. 
![iperf3 Results](/media/postImages/original/IMlHxjZGG8TpGCYhQreUDAEA)
![Bandwidth usage on AWS instance](/media/postImages/original/IMJWy5BTOMT4W7FPvG8lOU2Q)

I conducted these tests from several independent locations including my personal desktop. All with almost identical results. Therefore any traffic shaping polices that cloud affect the bandwidth of a single file transfer are not on our side.

PhilN-9266536 · Answer

Have you considered trying a different storage volume type like gp3 or io1 to see if this has impact on the speed, I have seen cases in the past where a change in this has had a significant impact on speeds.

Also without understanding the network architecture between AWS and your onsite server, could there be some sort of traffic inspection taking place that could slow this down ?

EC2 Instance with limited single connection speed

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