Steffen Gebert and Miklos Tirpak, emnify
How much is “up to 10 Gbps” for an EC2 instance? And what happens, if packets are smaller or fragmented? Over the years of running our mobile core’s network functions on AWS, we learned – the hard way – about numerous network limits. Many of them are (in the meantime) documented, but some are not.
In this presentation, we share our horror stories on what kept us awake at night. To make you better informed, we will explain limits such as packets per second and connection tracking and how those will affect your network traffic, once they are exceeded. We share, how you can (sometimes) monitor your remaining quotas, or at least how you can identify the reason, why your applications go haywire.
Finally, we highlight a couple of cases, where your next incident could be just a side note in the documentation.
Before switching into his new role, Steffen used to lead the infrastructure team at emnify, a mobile virtual network operator (MVNO) running custom-built mobile core networks for the Internet of Things on Amazon Web Services. His technical main interest is misusing AWS networking features to build a network-centric product on top of AWS (yes, it sometimes hurts).
Before joining emnify in 2017, he was a researcher at the University of Würzburg and received his PhD for his thesis on software-based networks.
Miklos works with the Packet Gateway team at emnify as an engineering manager on developing high-performance applications for packet processing with cutting-edge technologies. While such network applications are running on Amazon Web Services, packet per second rate and high reliability have always been in focus. Before emnify, he worked as a software engineer in the telecommunication and networking domains, designed and developed a patented policy engine for the routers of various telco protocols.
author = {Steffen Gebert and Miklos Tirpak},
title = {Please Give Me Back My Network Cables! On Networking Limits in {AWS}},
year = {2025},
address = {Santa Clara, CA},
publisher = {USENIX Association},
month = mar
}