How to calcuate egress volumes

Question

This may be the wrong forum, but I could not find a section for overall networking.

I understand the way in which egress is charged for Azure, but want to understand how the amount of data is measured.
Is it just the pure data, or does it include all the IP/TCP and other packet headers, and the associated responses /ACKS etc?
If using a simple TLS connection for a single API call, it works out about 1558 bytes from the client to the server and 1718 bytes from the server to the client before any data payload is considered (this is the TCP/TLS making connection and teardown).
So, are these bytes needed to be included in the egress calculation, or does Microsoft just measure the actual data payload?

Thanks

Answer 1

Hi Carin,

Network charges can occur in different scenarios based on Azure resource placement as well as inter-component communication in the application. If you haven’t planned your Azure usage with these charges in mind, it could impact your monthly cloud bill significantly.There are no data transfer charges when resources that are deployed in the same VNET and availability zone communicate with each other. The same is the case when the resources communicate to an Azure public endpoint in the same region. However, the data transferred between resources in different availability zones is chargeable, even if they are deployed in the same VNET.

Not sure where is your client hosted is from Internet or expressroute?

As per Microsoft the following Availability Zone data transfer is charged:

Data transfer, ingress and egress, from a VNet resource deployed in an Availability Zone to another resource in different Availability Zone in the same VNET
Following Availability Zone data transfer is NOT charged:

• Data transfer between VNet resources located in same Availability Zone
• Data transfer between a VNet resource and a Public IP address in the same Azure Region
• Data transfer between VNet resources located in peered VNets across Availability Zones. This data transfer will be charges as per VNet peering rates.

If the traffic is flowing via the Microsoft network the below charges will apply and it doesnt matter whether it is a simple TLS Connection or a adhoc session .

Hope this helps.
JS

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Answer 2

Hi @Cairn ,

Welcome to the Microsoft Q&A Platform. Thank you for reaching out & I hope you are doing well.
I understand that you would like to know how egress traffic is charged in Azure, with respect to packet headers and respective responses.

Apologies for the delay, as I was following up with our Product Team internally.

The egress charges are applied based on total packet size.
The Platform is agnostic to the headers.

Please let us know if you require more information on this.

Cheers,
Kapil