Rate Limits in a Profile: Packets, Bits and Bursts

Every profile sets four rate limits for each source IP: packets per second, a packet burst, bits per second and a bit burst. Traffic above them is dropped before it reaches your server.

A profile is a reusable set of protection rules for one game or protocol. Sterile ships a premade profile for most popular games, and you apply one to a port with a service rule. The limits are what stop a single address from flooding your server while every normal player stays well under them.

The four limits

• Packets per second: how many packets one source IP may send each second, on average.
• Packet burst: how many packets it may send at once above that rate before the limit applies. Players do not send evenly, so the burst absorbs short spikes such as a map load or a big fight.
• Bits per second: how much data one source IP may send each second, on average.
• Bit burst: how much data it may send at once above that rate. 0 means no byte limit. Any other value must be at least one full-size packet, 12,112 bits, or no packet could ever pass.

As an example, the premade UDP Rust profile allows 50k packets per second with a burst of 100k, and 960 Mbps with a burst of 1.9 Gbps, for each source IP.

Size the packet limit for the whole server on UDP

The limits apply to each source IP. There is one exception on UDP: for traffic that is not part of a player or session the network already knows about, the packet limit also caps the whole port. New connections and server-list queries count against it together, so a full server needs room for everyone joining at once.

If players report that they cannot join while your server is busy, the packet limit is the first thing to raise.

Use your own limits

To change the limits, open Profiles and choose New profile. Give it a clear name, pick the Protocol / Service for your game, then set the four limits. The panel shows the range each field allows.

When it is saved, choose Apply next to it to put it on a port, or move existing rules to it from your service's Service rules with Select rules.

Signs a limit is too tight or too loose

• Too tight: players lag, rubber-band or fail to join during busy moments while nothing in Analytics looks like an attack. Raise the burst first, then the per-second rate.
• Too loose: an attack from a small number of addresses still reaches the server. Lower the per-second limits towards what one real player sends, and keep the burst for spikes.

The filter level on the rule tightens limits further while an attack is under way, so you do not need to size them for the worst case yourself.

Need a hand?

Not sure what your game sends? Create a ticket with the game and your player count and we will suggest limits, or browse the support page.