Protocol Emulator http://www.protocolemulator.com is an extremely flexible portable tool designed by Rhonda to create specific networking environments required for software testing. It supports HTTP, SMTP, ESMTP ETRN, DSMTP, IMAP4, IMAP4rev1 and POP3 protocols, and potentially can be extended to support other Application Layer protocols.

Protocol Emulator can simulate various conditions that are not possible to get from production servers in a controlled manner. For instance:

• Timeouts,
• Invalid server responses,
• Data transmission errors,
• Obsolete or rare server behavior,
• Enormous amount of transmitted data,
• Unavailability of production servers.

Protocol emulator features:

• Free java source code,
• OS independence,
• Support of up to 65535 sessions assigned to individual ports,
• Separately manageable sessions,
• Flexible script-controlled behavior,
• C++ style script language,
• Emulation of both valid and invalid situations (positive and negative tests),
• Logging of all data communications between client and server.