Files with ca extension are in most cases cache files from Telnet Server network protocol which is used on the Internet or local area network (LAN) connections.

There are 3 other file types using
the CA file extension!

empty - DATAIR FlexPlus data file

empty - CLAN conversation analysis data

ca - Internet security certificate

Detailed description

Software that open ca file

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CA file extension - Telnet Server initial cache data

What is ca file? How to open ca files?

File type specification:

Various data file type icon Various data file type

File extension ca is associated with the Telnet Server. These .ca file stores initial cache data used to establish telnet connections. Often used by operating systems with the terminal interface, like UNIX or Linux. 

Telnet (Telecommunication network) is a network protocol used on the Internet or local area network (LAN) connections.

Updated: May 6, 2024

The default software associated to open ca file:

Microsoft Windows icon

Microsoft Corporation logoMicrosoft Windows  Microsoft Windows software

Company or developer:
Microsoft Corporation

A family of operating systems developed by the Microsoft Corp. The first Windows was released in 1985 as a GUI add-on to MS-DOS. MS-DOS based Windows versions were developed to 2000, when was released the last version called Windows ME. Windows based on NT core started in 1993. Windows NT family are developed to these days, the latest version is called Microsoft Windows 11.

macOS icon

Apple, Inc. logomacOS  Apple macOS / Mac OS X software

Company or developer:
Apple, Inc.

macOS is Unix-based desktop operating system, a successor of Mac OS X system for MacBook-family, iMac, Mac Mini and Mac Pro computers, developed and sold by Apple, Inc.

Mac OS X icon

Apple, Inc. logoMac OS X  Apple macOS / Mac OS X software

Company or developer:
Apple, Inc.

OS X or Mac OS X is Unix-based operating system developed by Apple Inc. for Macintosh computers. It contains basic core applications for everyday use, such as Finder basic file manager, Safari for Internet browsing, QuickTime for video, iTunes for managing audio data and iPod, iOS devices management , iMessage instant messaging, Mail, Contacts, Calendar and many more.

The latest version 10.11 of OS X is called El Capitan. It is available to purchase on Mac App Store as well as is distributed with new Mac computers and notebooks. It includes features to improve the security, performance, design and usability.

OS X operating system was replaced by new macOS in 2016!

Unix icon

The Open Group logoUnix  Linux/Unix software

Company or developer:
The Open Group

A multi-tasking operating system for various platforms, the first version of UNIX was released in 1969. It is developed by AT&T as well as various commercial vendors, universities and non-profit organizations. Traditional Original Unix systems have characteristics of Version 7 Unix or UNIX System V. Unix Specification have Mac OS X, Mac OS X Server, Solaris, AIX, HP/UX, z/OS etc. Other systems, such as Linux and BSD are called Unix-like or Unix system-like.

Linux operating systems icon

Various Linux developers logoLinux operating systems  Linux/Unix software

Company or developer:
Various Linux developers

Linux is family of Unix-based operating systems. Linux kernel supports variety of devices such as desktop computers, smart phones, tablet computers, routers, video game consoles etc. Linux is also leading operating system for servers. Linux is available for free in many distributions on the Internet.

Popular distributions for desktops are Ubuntu, Fedora, openSUSE, Debian. For servers are variants of Red Hat, Xandros, Slackware, Debian, SUSE etc.

Operating system for smart phones called Android is also based on Linux. Nokia developed Linux based operating systems for smart phones called MeeGo and Maemo.

Help how to open:

It doesn't seem likely that these cache files can be manually accessed by users.

How to convert:

As far as we know, no conversion for this type of .ca files is possible.

List of recommended software applications associated to the .ca file extension

Recommended software programs are sorted by OS platform (Windows, macOS, Linux, iOS, Android etc.)
and possible program actions that can be done with the file: like open ca file, edit ca file, convert ca file, view ca file, play ca file etc. (if exist software for corresponding action in's database).

Unspecified and all other actions for computer programs working with ca file - Telnet Server initial cache data

Click on the software link(s) for more information. Suggested software applications use ca file type for internal purposes and/or also by different way than common edit or open ca file actions.

Microsoft Windows:

Apple macOS / Mac OS X:

Main software associated with ca file by default:
macOS small icon macOS
Mac OS X small icon Mac OS X


Main software associated with ca file by default:
Unix small icon Unix
Linux operating systems small icon Linux operating systems

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