Computer Networks

The netstat -t command shows TCP connections, which are the active internet connections. Plain netstat shows all network connections, netstat -s shows summary statistics, and 'all the above' is incorrect since only the -t option specifically targets active internet connections.

URL-based recording level in LoadRunner always generates the web_submit_data function because it captures each request at the URL level regardless of the form submission method. HTML-based recording may generate web_submit_form or web_submit_data depending on the form structure. ICA and RDP are different protocols (Citrix and Remote Desktop).

The FTP Adapter is used for file exchange on remote file systems using the FTP protocol. It enables BPEL processes to read, write, and list files on remote FTP servers. The AQ Adapter (option B) is for Oracle Advanced Queuing, the File Adapter (option C) is for local file system operations, and RemoteFile Adapter (option D) is not a standard Oracle adapter.

ncpa.cpl is the Windows Control Panel file that opens Network Connections. The name stands for 'Network Control Panel Applet'. This file has been used across multiple Windows versions to access network connection settings and configurations.

HTTPS uses port 443 by default for encrypted HTTP communication over TLS/SSL. Port 80 is for HTTP, 8080 is a common alternate HTTP port, and 334 and 553 are not standard HTTPS ports.

WAS reads configuration at multiple levels: global server settings, protocol configurations for HTTP and non-HTTP protocols (like TCP), and application pool settings including process accounts. All these configuration types are essential for WAS to manage worker processes correctly.

HTTP.sys is the kernel-mode HTTP listener that provides request queuing, kernel-mode caching for improved performance, and request pre-processing before passing requests to worker processes. All these functions happen at the kernel level.

Windows Communication Foundation (WCF) was introduced as part of .NET Framework 3.0 in November 2006. This version also introduced Windows Presentation Foundation (WPF) and Windows Workflow Foundation (WF) as part of the same release.

WCF's default Message Exchange Pattern is Request/Response. Every operation call expects a response from the service, even if it's just an empty acknowledgment. To implement fire-and-forget messaging without waiting for a response, the operation must be explicitly marked with [OperationContract(IsOneWay=true)].

Web services can be invoked over both SOAP (XML-based protocol with Envelope/Header/Body) and HTTP (direct REST-style calls). RMI-IIOP and RPC are different protocols (Java RMI and generic RPC, not standard web service protocols).

QOS with Exactly Once (EO) delivery guarantee corresponds to tRFC (transactional RFC) in SAP, which ensures messages are delivered exactly once without duplication through transaction safety. sRFC is synchronous RFC, aRFC is asynchronous, and qRFC is queued RFC - none provide EO semantics.

Loosely coupled applications use messaging-based communication, with XML being a standard format for message payloads. FTP is file transfer, SMTP is email protocol, and RFC is a document specification - not communication methods.

WCF services support three hosting models: Self-hosting (in any managed application), IIS hosting (Internet Information Services for HTTP-based services), and WAS hosting (Windows Activation Service extends IIS to support non-HTTP protocols like TCP).

In the World Book/Endeca architecture, the Dictionary Index service typically runs on port 9500. This is a specific configuration detail for the Dictionary Index component. Port assignments vary by service - 8200, 9100, 9300 are used for other components.

The Time to First Buffer (TTFB) Breakdown graph specifically analyzes how much time each web page component spends on server processing versus network transfer before the first buffer is received. Throughput shows data transfer rates, Windows Resources monitors client machine performance, and Transaction Performance Summary aggregates overall transaction times.