Browse Prior Art Database

Method for a virtual loop-back connector to support SOL diagnostics

IP.com Disclosure Number: IPCOM000109314D
Publication Date: 2005-Mar-23
Document File: 3 page(s) / 12K

Publishing Venue

The IP.com Prior Art Database

Abstract

Disclosed is a method for a virtual loop-back connector to support serial over local area network (SOL) diagnostics. Benefits include improved functionality.

This text was extracted from a Microsoft Word document.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 55% of the total text.

Method for a virtual loop-back connector to support SOL diagnostics

Disclosed is a method for a virtual loop-back connector to support serial over local area network (SOL) diagnostics. Benefits include improved functionality.

Background

              SOL enables text redirection to a remote management console from the host basic input/output system (BIOS) screen, operating system (OS), and the console at the managed machine.

              SOL appears to the host managed system as an additional standard communications (COM) port. It is tested at the platform level with standard COM port diagnostics and certification tools. They require data transfer and data and control signals loopback, which can be performed at the console or firmware level. COM port control signals loopback typically uses a special connector that is defined by the testing tool. This connector connects COM port output controls to the COM port input controls and changes the outputs.

              Every test tool requires its special loop back connector. With a physical COM port, connecting different physical connectors is simple. With a virtual COM port, a flexible controlled solution is required.

              A virtual COM port does not have a physical connector and cannot easily be tested. Without passing all the tests, a COM port may fail the certification tests.

              A COM port is tested in external loop back by connecting some or all of the modem output control signals, such as RTS and DTR, to some or all of the modem input control signals:

•             CTS

•             DCD

•             DSR

•             RI

              The management console that is part of the test sends the loop-back information, such as test_connector_info0 and test_connector_info1, to the managed machine under test.

Description

              The disclosed method is a virtual loop-back connector to support SOL diagnostic testing. The method emulates the loop-back connection by enabling the host firmware to monitor the modem output control signal states and control the modem input control signal states.

              For example, RTS and DTR are bits in the modem control register (MCR) written by the host and readable by the management firmware. CTS,

DSR

,

RI

, and DCD are bits in the modem status register (MSR). They are written by the management firmware and read by the host software (see Figure 1).

              Note: Different loopback connector types can exist for each per specific test suit.

              For a loopback test example, the value of test_connector_info0 value is 0x60. The value of test_connector_info1 value is 0xF9 (see Figure 2).

              When the host writes to the MCR, the firmware extracts the RTS and DTR bits from the register and uses them as an index to a translation...