Transfers between AWS buckets from different organizations?

[Jim Lacy]

Hi folks-

This question is a bit into the weeds, but it's important from the perspective of avoiding egress charges in AWS S3 buckets.

Bucket A is owned by me/my organization in us-east-2, while Bucket B is owned by a different org but also in us-east-2.  I have access to both via access keys.

Conceptually, how does Globus accomplish the transfer?  Does it (effectively) pull data from Bucket A, then push it back up to Bucket B... and thus triggering egress charges?  Or is there some other magic happening behind the scenes that avoids this situation, similar to how the AWS CLI "sync" command can work?

I'm not a Globus admin, but from what I understand the Globus Connect Server(s) here at the University of Wisconsin reside on campus, not in a AWS EC2 instance in us-east-2, for example.  

Can anyone provide some insight?

Thanks!

[Karl Kornel]

Hi Jim, good morning!

First, a ‘fun fact’: If you pull up a Globus Collection’s record (https://app.globus.org/file-manager/collections/UUID/overview), the Domain field is a DNS domain, which you can look up to get the current DTN IPs.  And from that, you can confirm where the DTNs are located.

For any transfer involving a cloud bucket (S3, Drive, etc.), the data will flow through the Endpoints.  So, a bucket-to-bucket transfer will cause the source Endpoint to download objects from the source bucket, which it then transfers to the destination Endpoint; the destination Endpoint uploads the objects to the destination bucket.

So, if the DTNs are not located in the same cloud zone, then yes, an egress would be triggered.

One question, though: Does the University of Wisconsin have access to the AWS Egress Waiver program?  If yes, are your AWS Accounts able to take advantage of that program?  The Egress Waiver program gives you credits equal to your org’s egress costs, up to a limit: The limit is some % of your org’s monthly spend.  So, if your transfers are not massive, then there might not be an egress cost.

I suggest talking to the folks who manage AWS accounts.  They should know if your AWS accounts are covered by the egress waiver, and how much data transfer you should be able to do without charges.

Good luck!

 

~ Karl

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[Jim Lacy]

Perfect, exactly what I was looking for Karl.  Thank you!  And thanks for the tip as well... that is new to me.

Yes, the UW does have an egress waiver in place but I need to be able to budget for expenses.  The way the waiver works makes it hard to do so from an individual researcher perspective.  Egress might be covered, or it might not depending on what other folks on campus are doing each and every month.

Best wishes,

Jim

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From: 'Karl Kornel' via Discuss <dis...@globus.org>
Sent: Wednesday, January 7, 2026 2:00 PM
To: Jim Lacy <la...@wisc.edu>; Discuss <dis...@globus.org>
Subject: Re: [Globus Discuss] Transfers between AWS buckets from different organizations?

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