Best serial over Ethernet tools by situation: 2026 guide

Serial over Ethernet software carries the data of a COM port through a TCP/IP network. The tools differ less in speed than in what they can connect to: a program that knows only COM ports, a device server that expects RFC 2217, a Linux box, or a script. This guide sorts them by that.

By AGG Software. We make TCP COM Bridge, one of the tools below. The facts about the other products come from their own websites, read on 17 September 2026. "Not stated" means the vendor's page does not say. We did not benchmark the tools.

The tools at a glance

Tool	Licence	Runs on	Virtual COM port	Windows service	RFC 2217	Latest release listed
TCP COM Bridge (AGG Software)	Commercial, 21-day trial	Windows	Yes	Yes (Professional edition)	No	1.8.3 build 515
com0com with hub4com or com2tcp	Free, GPL	Windows	Yes, in pairs	Not stated	Yes (hub4com)	Not stated
tcp2com	Free, GPL v2	Windows	Not stated	Yes	Not stated	1.0.0; project updated April 2013
HW VSP3 (HW group)	Freeware, single port	Windows	Yes	Yes	Yes	3.1.2; the vendor marks the product "run-out"
VSPE (Eterlogic)	No licence needed on 32-bit Windows, licence required on 64-bit	Windows	Yes	Not stated	Not stated	1.5.8.489, 4 January 2026
ser2net	Free, GPL 2.0	Linux; can be built for Windows	No, it serves real ports	-	Yes	Not stated
Serial to Ethernet Connector (Electronic Team)	Commercial	See the vendor's site for the current platform list, protocol support and version

Pick by situation

A Windows program knows only COM ports, the device is somewhere on the network

You need a virtual COM port that leads to an IP address and a port. TCP COM Bridge, HW VSP3, VSPE and Serial to Ethernet Connector all create one. The far end can be a second copy of the same tool on the computer that owns the device, or a hardware device server in raw TCP mode. Setup with TCP COM Bridge: COM port redirector.

The device server insists on RFC 2217

With RFC 2217 the client sets the baud rate and the control lines of the remote port over the network. HW VSP3 and hub4com implement it on Windows, and ser2net on the serving side. TCP COM Bridge does not implement RFC 2217; use it with boxes that offer a raw TCP port, where the baud rate is set in the box itself.

It must be free, and a command line is fine

com0com is an open-source kernel-mode virtual serial port driver; its companions hub4com and com2tcp move the data to TCP. There is no graphical setup, and you maintain the configuration yourself. For one real port that should simply be reachable by telnet, tcp2com runs as a Windows service, but the project has not been updated since 2013: see TCP COM Bridge vs tcp2com. HW VSP3 is freeware for a single port; its vendor lists it as a run-out product.

Many ports on one machine, running unattended

Here a Windows service, a configuration you can copy, and per-connection counters matter more than price. TCP COM Bridge (Professional edition) starts as a service before anyone logs on, works with up to 255 COM ports on one computer, reconnects after a network failure and can buffer serial data while the link is down: serial device server setup.

One end runs Linux

Run ser2net on the Linux machine that owns the serial port and connect to it from Windows with any tool that speaks raw TCP, or RFC 2217 if you need remote baud rate control. TCP COM Bridge works with the raw TCP mode.

No network at all: two programs on one computer

That is a different kind of tool: a pair of linked virtual ports. com0com does it for free. Commercial options are our Virtual Null Modem and Virtual Serial Port Driver by Electronic Team (virtual-serial-port.org). To give several programs the data of one real device, see serial port splitter.

There is no computer near the device

Use a hardware device server (Moxa, Lantronix, Digi and others make them) at the device, and one of the virtual COM port tools above on your computer. More on the choice: software or a hardware device server.

The tools in detail

TCP COM Bridge

Our own tool. It connects physical or virtual COM ports to TCP or UDP as a client or a server, splits and shares ports, and keeps connections alive without supervision.

Up to 255 physical or virtual COM ports on one computer. The Standard edition is limited to two connections; the Professional edition has no connection limit.
The Professional edition adds the Windows service mode, UDP, keep-alive packets, the command line and traffic encryption (a proprietary algorithm between two copies of the program; for Internet links combine it with a VPN or the list of allowed IP addresses).
Handles dynamic IP addresses through a domain name.
Limits: Windows only; raw data stream, no RFC 2217. The trial works for 21 days with three connections, and each work session is limited to 128 KB or 2 hours.

Download TCP COM Bridge

com0com, hub4com, com2tcp

The project describes com0com as "an open source kernel-mode virtual serial port driver for Windows, available freely under GPL license". It creates pairs of virtual COM ports. hub4com lets several applications handle the data of one serial device and makes remote ports usable locally, with RFC 2217 support. com2tcp is a COM port to TCP redirector. Project page: com0com.sourceforge.net.

tcp2com

"tcp2com creates a bridge between a TCP socket and a serial port (COM). The program runs as a service under Windows NT." GPL v2, version 1.0.0, last project update in April 2013. No virtual COM ports are mentioned. Project page: tcp2com.sourceforge.net.

HW VSP3

A virtual serial port driver by HW group that redirects the data of a virtual COM port over TCP/IP to a device at a given IP address and port. It supports RFC 2217 and runs as an application or as a service. The single-port version is freeware; the multi-port version is tied to HW group hardware. The vendor lists version 3.1.2 and marks the product as "run-out". Vendor page: hw-group.com.

VSPE

Virtual Serial Ports Emulator by Eterlogic is a test-bench tool with many device types in one window, among them Pair, Splitter, TcpServer, TcpClient, Serial Redirector and UDP Manager. It needs no licence on 32-bit Windows and a licence on 64-bit Windows. The vendor lists version 1.5.8.489 of 4 January 2026 and support for Windows 10, Windows 11 and current Windows Server versions. Vendor page: eterlogic.com.

ser2net

An open-source program (GPL 2.0) that makes serial ports available over the network, mainly on Linux. It offers raw TCP, telnet with RFC 2217 and encrypted connections. Project page: github.com/cminyard/ser2net.

Serial to Ethernet Connector

A commercial serial over Ethernet product by Electronic Team and the closest commercial alternative to TCP COM Bridge. Check the vendor's site for the current platform list, protocol support and prices: electronic.us.

See what actually travels through the link

When a link is up but the device does not answer, look at the bytes. Advanced Serial Port Monitor opens the real or the virtual COM port and shows the traffic in HEX or ASCII.