---
name: "tcpser"
section: "1"
platform: "linux"
package: "tcpser"
version: "1.0rc12-2+b1"
release: "Debian 10 (Buster)"
platforms: ["linux"]
url: "https://new.carta.tech/tcpser"
---

# tcpser(1)

emulate a Hayes compatible modem

## NAME

tcpser - emulate a Hayes compatible modem

## SYNOPSIS

**tcpser** -d *dev* -s *speed* \[-l *log\_level* -t *tracing\_options*\] ...\
 **tcpser** -v *port* \[-l *log\_level* -t *tracing\_options*\] ...

## DESCRIPTION

This manual page documents briefly the **tcpser** command.

**tcpser** turns a PC serial port into an emulated Hayes compatible modem that  uses TCP/IP for incoming and outgoing connections.  It can be used to allow  older applications and systems designed for modem use to operate on the Internet.  **tcpser** supports all standard Hayes commands, and understands extended and vendor proprietary commands (though it does not implement many of them).  **tcpser** can be used for both inbound and outbound connections.

## OPTIONS

A summary of options is included below.

- **-h**

  Show summary of options.

- **-p**

  Port to listen on (defaults to 6400).

- **-t**

  Trace flags: (can be combined)

  - s

    modem input

  - S

    modem output

  - i

    IP input

  - I

    IP output

- **-l**

  Log level: 0 (NONE), 1 (FATAL) - 7 (DEBUG\_X) (defaults to 0).

- **-L**

  Log file (defaults to stderr).

- The following can be repeated for each modem desired (-s, -S, and -i will apply to any subsequent device if not set again):

  - **-d**

  Serial device (e.g. /dev/ttyS0).  Cannot be used with -v

- **-v**

  TCP port for VICE RS232 (e.g. 25232). Cannot be used with -d

- **-s**

  Serial port speed (defaults to 38400).

- **-S**

  Speed modem will report (defaults to -s value).

- **-I**

  Invert DCD pin.

- **-n**

  Add phone entry (number=replacement).

- **-a**

  Filename to send to local side upon answer.

- **-A**

  Filename to send to remote side upon answer.

- **-c**

  Filename to send to local side upon connect.

- **-C**

  Filename to send to remote side upon connect.

- **-N**

  Filename to send when no answer.

- **-B**

  Filename to send when modem(s) busy.

- **-T**

  Filename to send upon inactivity timeout.

- **-i**

  Modem init string (defaults to \`', leave off \`at' prefix when specifying).

- **-D**

  Direct connection (follow with hostname:port for caller, : for receiver).

## AUTHOR

tcpser was written by Jim Brain \<brain@jbrain.com\>.

This manual page was written by Peter Collingbourne \<pcc03@doc.ic.ac.uk\>, for the Debian project (but may be used by others).