Function Apps and Kubernets bandwidth limits

Question

Function Apps and Kubernets bandwidth limits

FedericoZarelli-6386 60

How are the bandwidth limits defined for Kubernetes and Function Apps, are those depending on the VM SKUs or are there are other limits.

As an example, A Storage Account can supports Ingress Traffic up to 60 Gbps - what are the equivalent traffic limits for incoming requests to AKS and Function apps?

Accepted answer

1 additional answer

Your answer

Answer 1

Alex Burlachenko 9,780

hi federico FedericoZarelli-6386,

great question, and thanks for throwing it out here ))

so, bandwidth limits in aks and function apps... it's a bit of a maze, but let's break it down simple-like. first off, with aks, the bandwidth ain't tied directly to the vm skus. nah, it's more about the underlying vmss (virtual machine scale set) and the azure network stack. for aks, the max bandwidth per node depends on the vm size u pick. like, if u go for a standard_d8s_v3, u get around 6 gbps, but a bigger beast like the standard_d32s_v3 can push up to 16 gbps. here's the official lowdown from microsoft: aks vm sizes doc.

now, function apps... that's a different story. since they're serverless, the limits are more about the app service plan u choose. if u're on the consumption plan, azure kinda auto-scales the bandwidth, but there's a soft cap around 2.5 gbps per instance. premium plans? they can go higher, but it's still not as straightforward as aks. check this out for more deets: function apps limits.

storage accounts with their 60 gbps... that's a whole other league :) aks and functions ain't gonna hit those numbers unless u're doing some serious scaling wizardry.

hope this clears things up

Best regards,

Alex

and "yes" if you would follow me at Q&A - personaly thx.
P.S. If my answer help to you, please Accept my answer
PPS That is my Answer and not a Comment

https://ctrlaltdel.blog/

FedericoZarelli-6386 60 Reputation points

2025-05-28T14:17:25.61+00:00

Hey Alex,
Thanks for the feedback - I haven't seen considerations on the bandwidth for aks or function app at the link you shared. Are they the correct one?

Also you mentioned that actual bandwidth is rather tight to underlying vmss (virtual machine scale set) and the azure network stack but then you mention to look into the vm sku bandwidth - what am I missing?

Many thanks!
Alex Burlachenko 9,780 Reputation points

2025-05-31T12:32:27.3933333+00:00
good catch Federico! u're totally right to double-check those links were more about general skus and scaling, not specifically bandwidth. my bad )) let me dig deeper and give u the real deal.

AKS bandwidth, so, here's the thing: aks does inherit its network limits from the vm skus, but it's not always front-and-center in the docs. the bandwidth per node is indeed tied to the vm size u pick, but azure doesn't shout about it in the aks docs. instead, u gotta look at the underlying vm specs.

for example

a standard_d8s_v3 gives u ~6 gbps (gigabits per sec)

a standard_d32s_v3 jumps to ~16 gbps

and if u go nuts with something like an E64is_v3, u can hit ~30 gbps

but wait there's a twist! the actual usable bandwidth also depends on

network acceleration (enabling accelerated networking bumps up throughput)

cluster load (if other pods are hogging the nic, u won’t hit max)

azure’s shared infra (sometimes the "theoretical max" isn’t real-world max)

here’s the actual vm bandwidth table (not in the aks docs, but this is where the numbers come from: azure vm sizes docs

Function Apps bandwidth

this one’s trickier because functions are serverless, and azure abstracts away the vm layer. but here’s the scoop:

consumption/elastic premium plans: azure dynamically scales, but per-instance limits are ~2.5 gbps (ish).

dedicated (app service plan) now u’re back to vm sku limits, same as aks.

the docs don’t spell out exact numbers because… well, azure likes to keep it fuzzy )). but if u really need to push traffic, a premium plan with bigger vms (like p3v3) will give u more headroom.

what u were missing (and it’s not ur fault!)

the vmss does define the bandwidth, but aks docs don’t repeat the vm specs u gotta cross-reference.

azure’s network stack adds overhead, so real-world throughput might be ~10-15% lower than the vm’s "max".

functions are a black box, but if u need predictable bandwidth, go dedicated (app service plan).

hope this helps!

rgds,

Alex

Answer 2

Dharani Reguri 1,175 Microsoft External Staff Moderator

Hi FedericoZarelli-6386,

Azure Kubernetes service nodes are backed by Azure Virtual Machines, so bandwidth is determined by the VM SKU used for the node pools. Each VM SKU has a defined maximum network bandwidth. For detailed information, please check the AKS size restrictions and quotas

Azure Function Apps bandwidth depends on the hosting plan: Consumption plans scale dynamically without explicit Gbps limits, while Premium/Dedicated plans derive capacity from their underlying instance SKUs.

If you have any further queries, let me know. If the information is helpful, please click on Upvote.

Thank you.

FedericoZarelli-6386 60 Reputation points

2025-05-28T14:18:38.9766667+00:00

Hi Dharani,
In the link you shared, can you point me to where the bandwidth limits are reported?

I couldn't find it there.

Many thanks,
Federico
Dharani Reguri 1,175 Reputation points Microsoft External Staff Moderator

2025-05-29T12:17:54.25+00:00

Hi FedericoZarelli-6386,

Each node in AKS is a Virtual Machine, and bandwidth is tied directly to the VM size. Please check the document about the VM Sizes and Virtual machine network bandwidth
Dharani Reguri 1,175 Reputation points Microsoft External Staff Moderator

2025-06-03T08:30:49.9333333+00:00

Hi FedericoZarelli-6386,

Just checking in to see if you have got a chance to see my response and Alex response to your question.

If it was helpful, please click "Upvote" on this post to let us know.

Thank You.

Share via

Function Apps and Kubernets bandwidth limits

1 additional answer

Your answer