[GH-ISSUE #5281] [Performance] VirtualNet(XTCP) throughput significantly lower than standard XTCP proxy

Originally created by @kami93 on GitHub (Apr 7, 2026). Original GitHub issue: https://github.com/fatedier/frp/issues/5281 ### Bug Description ## Description Hi, I am very interested in the new **VirtualNet** feature and have already integrated it into my workflow. However, I’ve observed a significant performance discrepancy: the network transfer rate is substantially slower when using VirtualNet compared to a standard Proxy setup, even though both are based on **XTCP**. ## Environment & Methodology I tested the download and upload rates between two nodes, both located behind distinct NATs. The tests were performed using `dd` over `ssh`. ### 1. VirtualNet (XTCP) **Download**: ~450 kB/s **Upload**: ~386 kB/s ```bash # Test download rate $ SIZE=20 && ssh <user>@100.0.0.1 "dd if=/dev/urandom bs=1M count=$SIZE status=progress" | dd of=/dev/null 20971520 bytes (21 MB, 20 MiB) copied, 46.6435 s, 450 kB/s # Test upload rate $ SIZE=20 && dd if=/dev/urandom bs=1M count=$SIZE status=progress | ssh <user>@100.0.0.1 "cat > /dev/null" 20971520 bytes (21 MB, 20 MiB) transferred 54.364s, 386 kB/s ``` ### 2. Standard Proxy (XTCP) **Download**: ~2.6 MB/s **Upload**: ~1.9 MB/s ```bash # Test download rate $ SIZE=20 && ssh 127.0.0.1 -p49999 "dd if=/dev/urandom bs=1M count=$SIZE status=progress" | dd of=/dev/null 20971520 bytes (21 MB, 20 MiB) copied, 7.93457 s, 2.6 MB/s # Test upload rate $ SIZE=20 && dd if=/dev/urandom bs=1M count=$SIZE status=progress | ssh <user>@127.0.0.1 -p49999 "cat > /dev/null" 20971520 bytes (21 MB, 20 MiB) transferred 11.008s, 1905 kB/s ``` ## Observation The VirtualNet throughput is roughly 5–6x slower than the standard XTCP proxy under the same network conditions. Could you look into whether there is an inherent overhead or a specific bottleneck in the VirtualNet implementation? ## Configuration Below are the `frpc` configs for both nodes (sensitive information redacted): ### node1 (server) ```toml serverAddr = 'FRPS-SERVER' serverPort = 'FRPS-PORT' transport.protocol = 'quic' featureGates = { VirtualNet = true } virtualNet.address = "100.0.0.1/16" [[proxies]] name = 'NAME-VNET' type = "xtcp" secretKey = 'SECRET-VNET' [proxies.plugin] type = "virtual_net" [[proxies]] name = 'NAME-PROXY' type = "xtcp" secretKey = 'SECRET-PROXY' localIP = "127.0.0.1" localPort = 22 ``` ### node2 (client) ```toml serverAddr = 'FRPS-SERVER' serverPort = 'FRPS-PORT' transport.protocol = 'quic' featureGates = { VirtualNet = true } virtualNet.address = "100.0.0.2/16" [[visitors]] name = 'NAME-VNET' type = "xtcp" serverName = 'NAME-VNET' secretKey = 'SECRET-VNET' bindPort = -1 [visitors.plugin] type = "virtual_net" destinationIP = "100.30.0.1" [[visitors]] name = 'NAME-PROXY' type = "xtcp" serverName = 'NAME-PROXY' secretKey = 'SECRET-PROXY' bindAddr = "127.0.0.1" bindPort = 49999 ``` ### frpc Version 0.68.0 ### frps Version 0.68.0 ### System Architecture linux/amd64 (node1), macos/aarch64 (node2), and linux/amd64 (frps) ### Configurations see **Configuration** section. ### Logs _No response_ ### Steps to reproduce _No response_ ### Affected area - [ ] Docs - [ ] Installation - [x] Performance and Scalability - [ ] Security - [x] User Experience - [ ] Test and Release - [ ] Developer Infrastructure - [x] Client Plugin - [ ] Server Plugin - [ ] Extensions - [ ] Others

gitea-mirror commented

2026-05-05 14:35:00 -06:00

Owner

Originally created by @kami93 on GitHub (Apr 7, 2026).
Original GitHub issue: https://github.com/fatedier/frp/issues/5281

Bug Description

Description

Hi, I am very interested in the new VirtualNet feature and have already integrated it into my workflow. However, I’ve observed a significant performance discrepancy: the network transfer rate is substantially slower when using VirtualNet compared to a standard Proxy setup, even though both are based on XTCP.

Environment & Methodology

I tested the download and upload rates between two nodes, both located behind distinct NATs. The tests were performed using dd over ssh.

1. VirtualNet (XTCP)

Download: ~450 kB/s
Upload: ~386 kB/s

# Test download rate
$ SIZE=20 && ssh <user>@100.0.0.1 "dd if=/dev/urandom bs=1M count=$SIZE status=progress" | dd of=/dev/null
20971520 bytes (21 MB, 20 MiB) copied, 46.6435 s, 450 kB/s

# Test upload rate
$ SIZE=20 && dd if=/dev/urandom bs=1M count=$SIZE status=progress | ssh <user>@100.0.0.1 "cat > /dev/null"
20971520 bytes (21 MB, 20 MiB) transferred 54.364s, 386 kB/s

2. Standard Proxy (XTCP)

Download: ~2.6 MB/s
Upload: ~1.9 MB/s

# Test download rate
$ SIZE=20 && ssh 127.0.0.1 -p49999 "dd if=/dev/urandom bs=1M count=$SIZE status=progress" | dd of=/dev/null
20971520 bytes (21 MB, 20 MiB) copied, 7.93457 s, 2.6 MB/s

# Test upload rate
$ SIZE=20 && dd if=/dev/urandom bs=1M count=$SIZE status=progress | ssh <user>@127.0.0.1 -p49999 "cat > /dev/null"
20971520 bytes (21 MB, 20 MiB) transferred 11.008s, 1905 kB/s

Observation

The VirtualNet throughput is roughly 5–6x slower than the standard XTCP proxy under the same network conditions. Could you look into whether there is an inherent overhead or a specific bottleneck in the VirtualNet implementation?

Configuration

Below are the frpc configs for both nodes (sensitive information redacted):

node1 (server)

serverAddr = 'FRPS-SERVER'
serverPort = 'FRPS-PORT'
transport.protocol = 'quic'
featureGates = { VirtualNet = true }

virtualNet.address = "100.0.0.1/16"

[[proxies]]
name = 'NAME-VNET'
type = "xtcp"
secretKey = 'SECRET-VNET'
[proxies.plugin]
type = "virtual_net"

[[proxies]]
name = 'NAME-PROXY'
type = "xtcp"
secretKey = 'SECRET-PROXY'
localIP = "127.0.0.1"
localPort = 22

node2 (client)

serverAddr = 'FRPS-SERVER'
serverPort = 'FRPS-PORT'
transport.protocol = 'quic'
featureGates = { VirtualNet = true }

virtualNet.address = "100.0.0.2/16"

[[visitors]]
name = 'NAME-VNET'
type = "xtcp"
serverName = 'NAME-VNET'
secretKey = 'SECRET-VNET'
bindPort = -1
[visitors.plugin]
type = "virtual_net"
destinationIP = "100.30.0.1"

[[visitors]]
name = 'NAME-PROXY'
type = "xtcp"
serverName = 'NAME-PROXY'
secretKey = 'SECRET-PROXY'
bindAddr = "127.0.0.1"
bindPort = 49999

frpc Version

0.68.0

frps Version

System Architecture

linux/amd64 (node1), macos/aarch64 (node2), and linux/amd64 (frps)

Configurations

see Configuration section.

Logs

No response

Steps to reproduce

Affected area

Docs
Installation
Performance and Scalability
Security
User Experience
Test and Release
Developer Infrastructure
Client Plugin
Server Plugin
Extensions
Others

gitea-mirror added the

question

label 2026-05-05 14:35:00 -06:00

Rows
Columns

[GH-ISSUE #5281] [Performance] VirtualNet(XTCP) throughput significantly lower than standard XTCP proxy #4080