Share COM port over network

To share existing COM port (for example, COM1) with applications running on multiple computers (A and B), you can use TCP Server device and TCP Client device.

Important: in case of connectivity issues please configure firewall rules for 
EterlogicVspeDeviceManagerService.exe located in VSPE program folder on server and client computers.

Please note that by default TCP connection is not encrypted.
To encrypt traffic, configure TLS security settings.

If you do not want to forward modem registers (RTS/DTR etc),
You can ignore Control port settings

Host computer (data source), IP address 192.168.1.100
- Create TcpServer (COM1)
  - Data port: 5555
  - Control port: 6666

Client computer A
- Create Connector COM5
- Create TcpClient (COM5)
  - Remote TCP host: 192.168.1.100
  - Data port: 5555
  - Control port: 6666

Client computer B
- Create Connector COM5
- Create TcpClient (COM5)
  - Remote TCP host: 192.168.1.100
  - Data port: 5555
  - Control port: 6666

Data flow diagram

Configuring firewall

To incoming connections to Server computer (the one TcpServer device is running on) you need to configure Windows Firewall.

Add new Inbound rule for program "C:\Program Files\Eterlogic Software\Virtual Serial Ports Emulator (x64)\EterlogicVspeDeviceManagerService.exe" (path may be differrent on your computer depending on installation folder and computer architecture)
Configure Protocol and Ports
- Protocol Type: TCP
- Local Port: Specific ports, add TCP ports for TcpServer device (for example "5555, 5556")
- External IP addresses: list of remote (external) IP addresses which are allowed to connect

Inbound rule

Specifying inbound rule protocol and TCP port

Alternatively, you can run PowerShell as Administrator and add the rule by running New-NetFirewallRule cmdlet as in the example below (specify -Protocol TCP or -Protocol UDP, -Profile, -LocalPort, -RemoteAddress and other properties if needed):

Example: allowing VSPE to listen on specific TCP ports (5555 and 5556) and accept incoming connections from all remote IP addresses

New-NetFirewallRule -DisplayName "VSPE TcpServer" -Direction Inbound -Program "C:\Program Files\Eterlogic Software\Virtual Serial Ports Emulator (x64)\EterlogicVspeDeviceManagerService.exe" -Action Allow -Profile Any -Protocol TCP -LocalPort 5555,5556

Example: allowing VSPE to listen on specific TCP ports (5555 and 5556) and accept incoming connections only from specified remote IP addresses (192.168.1.100 and 192.168.1.101)

New-NetFirewallRule -DisplayName "VSPE TcpServer" -Direction Inbound -Program "C:\Program Files\Eterlogic Software\Virtual Serial Ports Emulator (x64)\EterlogicVspeDeviceManagerService.exe" -Action Allow -Profile Any -Protocol TCP -LocalPort 5555,5556 -RemoteAddress 192.168.1.100,192.168.1.101

Example: allowing VSPE to listen on all TCP ports and accept incoming connections from all remote IP addresses

New-NetFirewallRule -DisplayName "VSPE TcpServer all ports" -Direction Inbound -Program "C:\Program Files\Eterlogic Software\Virtual Serial Ports Emulator (x64)\EterlogicVspeDeviceManagerService.exe" -Action Allow -Profile Any -Protocol TCP

Example: allowing VSPE to listen on all TCP ports and accept incoming connections only from specified remote IP addresses (192.168.1.100 and 192.168.1.101)

New-NetFirewallRule -DisplayName "VSPE TcpServer all ports" -Direction Inbound -Program "C:\Program Files\Eterlogic Software\Virtual Serial Ports Emulator (x64)\EterlogicVspeDeviceManagerService.exe" -Action Allow -Profile Any -Protocol TCP -RemoteAddress 192.168.1.100,192.168.1.101

Example: allowing VSPE to listen on all UDP ports and accept UDP packets from any external IP addresses

New-NetFirewallRule -DisplayName "VSPE UdpManager all ports" -Direction Inbound -Program "C:\Program Files\Eterlogic Software\Virtual Serial Ports Emulator (x64)\EterlogicVspeDeviceManagerService.exe" -Action Allow -Profile Any -Protocol UDP

Example: allowing VSPE to listen on all UDP ports and accept UDP packets only from specific remote IP addresses (192.168.1.100 and 192.168.1.101)

New-NetFirewallRule -DisplayName "VSPE UdpManager all ports" -Direction Inbound -Program "C:\Program Files\Eterlogic Software\Virtual Serial Ports Emulator (x64)\EterlogicVspeDeviceManagerService.exe" -Action Allow -Profile Any -Protocol UDP -RemoteAddress 192.168.1.100,192.168.1.101

Compressing data traffic sent over network (for data port only!)

To compress/decompress traffic, you should add Compress data transformer to "TCP connection" flow and Decompress data transformer to "COM port" flow. Do not forget to add the same transformers to both TCP Server device and TCP Client device.

TCP server transformers for compression support

TCP client transformers for compression support

To add encryption/decryption to compressed traffic, you should add Encrypt data transformer (after Compress) to "TCP connection" flow and Decrypt data transformer to "COM port" flow (before Decompress).

See also: