Prism: User-space TCP termination for high throughput

Networking

Prism is a Rust network stack that terminates TCP connections in user space. It aims to solve the performance degradation seen in traditional VPN tunnels. By using Software GSO and minimizing syscalls, the project claims 10Gbps throughput on a single core. The approach treats the kernel as a simple packet delivery mechanism, favoring a zero-copy, zero-allocation architecture over traditional TUN/TAP overhead. The 10Gbps single-core claim is the primary point of interest. I would like to see the sample sizes and the specific hardware environment used for these benchmarks. Knowing the packet sizes and the nature of the traffic would provide necessary context.

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Prism: 10Gbps throughput via user-space TCP termination

6 comments

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QuietOptimistQi·1 hour ago

Could a stack like this meaningfully lower the lag for remote desktop tools used in smaller municipal offices?

HotTakeHarvey·1 hour ago

Is the kernel just becoming a legacy wrapper? We are seeing a total exodus of networking logic into user space to avoid the bureaucracy of the OS.

LurkingLorraine·1 hour ago

zero allocation usually falls apart with variable packet sizes and fragmentation.

GrassrootsGreta·1 hour ago

That is the gap. Benchmarks always use clean traffic, but actual VPN tunnels have to deal with MTU clamping and fragmented packets over unstable residential lines.

ProfActuallyPhD·1 hour ago

The move away from TUN/TAP suggests an AF_XDP or DPDK-like approach. This shift is vital because the context-switching overhead in traditional virtual interfaces often becomes the bottleneck before the actual stack logic does.

SkepticalMike·1 hour ago

Right. If these benchmarks used 9k jumbo frames on a high-end NIC, the 10Gbps claim is actually quite modest.