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0-9 and Special Characters
.NET COM Interop
COM interoperability is the ability to use ActiveX COM components in a .NET application. The .NET Framework creates a .NET wrapper when a COM component is added to a .NET application and communicates with the COM component using the .NET wrapper as a go-between.
A
Absolute Position
Absolute positioning allows an HTML object to be placed anywhere on a web page, using coordinates rather than a layout technique such as tables.
ActiveX
ActiveX controls are software modules based on Microsoft's Component Object Model (COM). COM technology enables software components to interact with one another and is fundamental to Microsoft's pre-.NET component-based development model. All PowerTCP Tool products are built using ActiveX technology and can be used in any development environment that fully supports COM components.
AES
AES (Advanced Encryption Standard) is a symmetric key encryption which has replaced the DES standard. AES is considered a highly secure algorithm that improves on previous weaknesses to brute force attacks. The PowerTCP Zip Compression Tool implements AES encryption, while PowerTCP Zip Compression for .NET uses the Gladman implementation of AES and is compatible with WinZip 9.0. PowerTCP SSL Sockets for .NET includes the SymmetricCryptoStream class that simplifies encrypting data.
Ajax
Asynchronous JavaScript and XML, or Ajax is a web development technique for creating highly responsive and efficient applications. This technique relies on the combination of several core technologies including HTML, CSS, JavaScript, and the XMLHttpRequest object. Most modern browsers support all or most of these technologies, thereby making Ajax a reliable approach.
Archive
An archive is a group of files or streams. The component within PowerTCP Zip Compression for .NET is called Archive to designate a collection of files or streams.
ASN.1
ASN.1 (Abstract Syntax Notation number 1) is a language for describing structured information; typically information that is sent across a network. It is widely used in Internet protocol specifications such as SNMP.
ASP Application
A web-based Active Server Page application that runs on a web server. ASP applications are often written using a combination of JavaScript, VBScript, and HTML. The .NET equivalent is ASP.NET.
ASP.NET Validation Controls
ASP.NET validation controls are a set of server controls that validate user input posted back to the same page. A supported component allows a validation control to access its posted data.
Asynchronous
Asynchronous operations are methods that execute in Windows Forms applications without interfering with the User-Interface (UI).
Authentication
A process of verifying that a computer or user is who that computer or user claims to be. This is done using Digital Certificates when using SSL. The PowerTCP SSL Tool includes controls that enable this capability.
Automatic Zip
The PowerTCP FTP Tool uses the zip engine to dynamically zip or unzip data when the data transfer type is specified as ftpZip.
AutoReceive
AutoReceive is an option available in PowerTCP for .NET products that simplifies the process of communicating over a network. When set, data is automatically received and an EndReceive event is raised with no explicit call to BeginReceive required.
B
Base Classes
A generic class from which other more specific classes are derived from using inheritance. PowerTCP .NET products often provide access to their base classes so that developers can build their own custom solutions without having to recreate low-level capabilities. See EnhancedStream, PipeStream, and SegmentedStream.
Blocking
Synchronous, or blocking execution refers to a program that will not execute the next line of code until the current function call has completed. This is common is scripting applications that lack mechanisms for events or callbacks. Blocking operations can also be easier to program as no notification is required when an operation completes. PowerTCP products offer both blocking and non-blocking operations.
C
CertificateList
The CertificateList control is an interface for selecting certificates. The CertificateList Control is derived from a standard ListView window.
CertificateStore
The CertificateStore object is a Dart class that represents the Microsoft certificate store. A certificate store is a database on the operating system that holds certificates. The user store is the certificate store located in the HKEY_CURRENT_USER key. The machine store is the certificate store located in the HKEY_LOCAL_MACHINE key. Applications installed as a service should store their certificates in the machine store since there is no current user when running as a service.
Character Set
The numeric codes used to represent the characters of a particular country or place. ASCII (American Standard Code for Information Interchange) is the most common and well known character set. For example, European countries use an extension of ASCII known as ISO-8859-1 (ISO Latin-1 that extends ASCII to 8-bit characters) while Japan uses ISO-2022-JP among others.
Client
An application that depends on and communicates with a server to deliver complete functionality. Examples of clients include FTP clients, Email clients, and web browsers.
Client Component
A component or control that must be installed on a client computer before it can be used, rather than working on the server.
Client-side API
A JavaScript class with an interface that can be accessed by users who wish to take advantage of the client-side functions contained within.
Client-side Authentication
Client-side authentication is when a server requests the client's certificate for authentication purposes before being allowed to communicate with the server. This assures that the client is not an imposter.
Code-behind
Code-behind refers to ASP.NET code that is contained within a separate class file. This allows a clean separation of your HTML from your presentation logic. Code-behind normally has a corresponding .aspx page with HTML tags.
Color Picker
An interactive dialog used for selecting the color of a particular HTML element, such as a font or background color. PowerWEB TextBox for ASP.NET includes several color pickers, providing options depending on the bandwidth requirements of the user.
COM+
COM+ (pronounced "COM plus") makes it easier to design and construct distributed, transactional, and component-based applications using a multi-tiered architecture. COM+ also supports the use of many new services, such as Just-in-Time Activation, object pooling, and Microsoft Transaction Server (MTS) 2.0. The use of COM, DCOM, and COM+ in application design will eventually be entirely replaced by the Microsoft .NET Framework.
Cookies
Cookies are very small text files that Web sites place on a computer so that the browser can remember certain information. For example, cookies can contain user IDs, passwords, and the last visit date. They can be also used to store personal preferences and are often used with shopping carts, allowing the cart to remember what items were added if a user leaves the site. Some sites use temporary cookies (called session cookies) that are deleted when you exit your browser. Others place persistent cookies, which stay on your hard drive for longer periods.
Custom Font
Both the PowerTCP Emulation for .NET and the PowerTCP Emulation Tool include a fixed-width raster font designed for the proper display of VT characters.
D
Daemon
A process that listens for requests or forwards a request to another process for handling. Daemons run continuously, usually in the background. A daemon is often used as a building block for server applications. For example, the http daemon responds to HTTP requests from a web client. The PowerTCP Winsock Tool includes a Daemon control while PowerTCP Sockets for .NET includes a Server component that is a more advanced multi-threaded server. The PowerTCP Server Tool includes a Server component for more advanced server applications.
DartStream
The DartStream Object is used to manage a streamed buffer to/from memory or a file. This allows the user to work with streamed data in environments that don't natively support streaming such as VB6. Many PowerTCP Tools use a DartStream as a data type, allowing the developer to specify both memory and files as sources or destinations for their data.
DartStreams
DartStreams is a collection of DartStream objects.
DartStrings
DartStrings is a string collection used as a data type in many PowerTCP Tools products. String manipulation in VB is very inefficient. DartStrings overcomes these performance deficiencies, plus adds searching and formatting capabilities, such as parsing by delimiter.
Data Source
The source of the data being processed by the VT control. A real-time source is one like a Telnet connection that is actively returning data from a server, as opposed to a file that has previously captured data from a Telnet session.
Data Stream
The underlying TCPStream that is sending or receiving data to/from the socket. PowerTCP for .NET products often provide an interface to the underlying TCP class for a greater level of customization.
Datagram
An independent and self-contained packet of data. A datagram carries comprehensive information so it can be routed from source to destination without reliance on a pre-existing connection, or any prior exchanges between source and destination. Datagrams are used in reference to UDP, which is a "connection-less" protocol.
Debug Server
Many PowerTCP Tools include a Debug Server application that can be used to help identify potential problems in a client application. The Debug Server is a TCP Listener that displays any incoming data, and allows for any response to be manually entered by the user.
Decoding
MIME decoding is a technique of turning encoded 7-bit data back into its original 8-bit non-ASCII form. The development of MIME was necessary because only sending 7-bit ASCII text was extremely limiting, especially with the advent of multimedia files. Sending other, non-ASCII files was a challenge, as most of these file types in their natural state are 8-bit files. Some mail transfer agents only have the ability to transfer 7-bit data. MIME specified a new way to structure messages, as well as algorithms, to encode the 8-bit data so that non-ASCII files could be transported. See Encoding.
Design-time Editor
Any interactive application that is made available by a component or control during design-time (when a developer is writing code in the development environment, as opposed to running the application) that assists in the code writing or development process. Properties set from the editor will persist back to the control or component. PowerTCP for .NET components often include design-time editors for testing server connections.
Design-time Visual Interface
See Design-time Editor.
Digital Certificate
A digital certificate, otherwise known as an x.509 certificate, is a common credential that provides authentication. A trusted organization, called a Certificate Authority (CA), assigns a certificate to a user or entity and the user or entity then uses the certificate to prove itself to the other side. A user may configure a system to accept any number of Certificate Authorities. A user submits a certificate request to a CA and the CA returns a certificate for the user to use. Certificate Authorities include: Verisign, Thawt, Microsoft Certificate Server (user defined authority) plus many others. There always needs to be a digital certificate installed to operate as a server. There is only need for a digital certificate installed on a client if the server requests authentication.
DNS
DNS (Domain Name Service) is an Internet service that translates domain names to or from IP addresses. This is the foundation of using domain names on the Internet. Domain Name Servers maintain central lists of IP addresses and their mapped domain names. A DNS Client, whether a web browser or another application, is responsible for sending lookup requests to the DNS Server. The PowerTCP Winsock Tool includes a DNS control and PowerTCP Sockets for .NET includes a DNS component. The PowerTCP Server Tool includes a DNS server component.
DNS Client
An application that is responsible for making DNS lookups to a DNS server. The PowerTCP Winsock Tool includes a DNS control and PowerTCP Sockets for .NET includes a DNS component. The PowerTCP Server Tool includes a DNS server component.
DNS Server
These are the servers that match up a domain with a specified IP address. This is necessary because computers only understand the IP address for your domain. The PowerTCP Server Tool includes controls that enable developers to build DNS Server applications.
Dynamic HTML Content
HTML content that is dynamically created depending on the request that is received from a client or other circumstances that the programming logic dictates. Non-dynamic HTML content can be a static web page that resides on a server and is returned to the requesting client without modification.
E
Emulation
Emulation is behavior like another type of entity, usually as in "terminal emulation," where the behavior of video terminal hardware is emulated.
Encoding
MIME encoding is a technique for turning 8-bit data into 7-bit ASCII data. The development of MIME was necessary because sending only 7-bit ASCII text was extremely limiting, especially with the advent of multimedia files. Sending non-ASCII files was a challenge, as most other file types in their natural state. Some mail transfer agents only have the ability to transfer 7-bit data. MIME specified a new way to structure messages, as well as algorithms to encode the 8-bit data so that non-ASCII files could be transported. "Base64" is typically used to encode binary files, encoding every 3 bytes into 4 ASCII characters. Each "line" is of the same length, typically 64 or 76 characters. "Quoted-Printable" is typically used to encode files that are predominantly readable already, and only encodes bytes that fall outside of the range of printable characters. These bytes are encoded as 3 ASCII characters beginning with "=" and ending with 2 characters representing the hex value of the byte.
EnhancedStream
EnhancedStream is a class derived from the base stream class that adds type conversion, stream copying, and saving capabilities. For example, EnhancedStream.Save allows you to save Stream data directly to a file. EnhancedStream.ToString returns a string representation of the data contained within the Stream. All PowerTCP for .NET stream classes (such as SegmentedStream, SslStream, etc) inherit from this class.
Escape Sequences
An escape sequence is the combination of the escape character "\" followed by other characters or codes indicating specific actions.
ESMTP
Enhanced SMTP is an extension of the SMTP protocol that allows for new features. Not all mail servers implement ESMTP so those features can only be used when both the client and the server conform to the protocol. For a list of features that are supported by ESMTP, please view the documentation. All PowerTCP Mail products support ESMTP.
Event-driven
An event driven application responds to conditions in real-time using an event notification mechanism to inform the application when a process or procedure has occurred. Progress indicators are an example of event driven implementations. Event driven applications are central to using non-blocking functions and writing applications in an asynchronous manner.
Explicit SSL
Explicit SSL is a technique of establishing a secure connection. The client sends a request for SSL encryption in the clear, with several other commands possibly preceding the SSL request. The server acknowledges, and the process of securing the connection begins. This is an alternative to Implicit SSL.
F
FileStore
This object is a collection of File objects, representing files or memory buffers that can be compressed or uncompressed. The FileStore is automatically populated when the QuickZip, QuickUnzip, and Load methods are called. Files and buffers can be added using the Add method. The FileStore object can be created and used independently from the Zip control; an independent FileStore object cannot fire events, but it can carry out all other operations on its own.
Firewall
A firewall is a program, often located at a network gateway server, which protects the resources of a private network from external access.
FirewallReady
Enables Secure FTP communications over a Firewall. This only works when the PowerTCP SecureFTP and SecureFTPServer controls included in the PowerTCP SSL Tool are used together.
Fixed-width Raster
A font created as a graphic bitmap image and only available in a fixed size - not scaleable like a True-Type font.
FTP
FTP (File Transfer Protocol) is an application protocol that uses the Internet's TCP/IP protocols. FTP is commonly used to transfer Web page files from their creator to the host web server on which they will reside. The protocol is also commonly used to download programs and other files from other machines. The FTP protocol is described in RFC 959.
FTP Client
An FTP client is an application or component that communicates with an FTP server.
FTP Server
An FTP Server is a software application that responds to the requests of FTP client applications. An FTP Server may be used to host computer files. The PowerTCP Server Tool includes controls that enable developers to build such applications.
FTPS
FTPS describes an FTP connection that runs over SSL, providing security. Controls for securing file transfers are included in The PowerTCP SSL Tool and the PowerTCP FTP for .NET Tool.
G
GET
An HTTP command that makes a request for a specific resource from a server. The GET command is the most common HTTP command and is often used to request a web page or another resource from a server.
Graceful Degradation
Graceful degradation or fault-tolerance is the property of a system that continues operating properly in the event of failure of some of its parts. For example, an application using Ajax technologies should gracefully degrade by detecting the requesting browser capabilities. Once these capabilities are assessed, the application would render functionally equivalent code to the client.
gZip
A compression utility often found on UNIX operating systems. Unlike the common zip implementation found on Windows operating systems, gZip is designed to compress a single file, rather than compress and store multiple files into a single file package.
H
Headers
Message headers identify information about a message or its parts. Headers normally decorate the beginning of a message or part. Example header information includes the To, From, Subject, CC, and Date fields, plus others, including those added by servers and mail filtering applications.
HTML Mail
HTML mail merges a web page with an email message. Creating such mail requires a construction and complex combination of message parts. Both PowerTCP Mail and PowerTCP Mail for .NET provide shortcut methods for creating such messages, and also allow for the manual construction of messages when fine-tuning is required.
HTML Parsing
HTML parsing as related to the PowerTCP Web Enterprise Tool is a technique for parsing the structure of an HTML page and returning the contents in an object-oriented manner that can be easily used by a developer in an application. The WebPage object is responsible for this operation.
HTTP
HTTP (Hypertext Transfer Protocol) is the underlying protocol used by the World Wide Web. This protocol defines how messages are transmitted and formatted plus defines how Web servers and browsers should act in response to various commands. For example, entering a URL in a browser sends an HTTP command to a Web server directing it to get and transmit the requested Web page. The PowerTCP Web Enterprise Tool and the PowerTCP Web Tool include controls for handling HTTP client-side requests while the PowerTCP WebServer Tool includes a control for building an HTTP server.
HTTPS
HTTPS (Hypertext Transfer Protocol Secure) is a secure version of HTTP, implemented using the secure sockets layer, otherwise known as SSL. The actual implementation is just the HTTP protocol running over the SSL protocol. All PowerTCP HTTP products also support HTTPS.
I
Idle
The IMAP IDLE extension is a mode in which the client is alerted to new messages automatically without polling from the client (for example, by transmitting a periodic NOOP command).
Image Support
The ability to easily upload and insert images, while also having the ability to edit the characteristics of an image during or after insertion.
IMAP4
The Internet Message Access Protocol. The IMAP4 protocol is a sophisticated alternative to the POP3 protocol for message downloading; allowing more options for mailbox and message handling. The latest version is based on RFC 2060. Outlook can operate as an IMAP4 client and Microsoft Exchange can be used as an IMAP4 server.
Implicit SSL
Implicit SSL is when an SSL connection is established immediately after the TCP handshake is complete. This is an alternative to Explicit SSL.
Integrated Help 2.0
Integrated help is a reference to version 2.0 of the Microsoft help engine that is used with Visual Studio .NET. This new help engine uses a revised layout format and is available natively while using Visual Studio. Using the 2.0 engine for third party products enhances the user experience when developing software, as transitions from Microsoft pages to third party pages is seamless. All PowerTCP for .NET products use the new help engine. Integrated help includes capabilities such as F1 support and dynamic help.
J
JIT
(Just-in-time) Is a compilation mechanism that compiles source code into machine code on the "fly" when required, rather than at an earlier stage. This technique is used by .NET and Java.
K
Key Re-mapping
Key mapping is the ability to remap the keyboard to correspond with a previously defined set of responses to key presses. Re-mapping keys when using the PowerTCP Emulation Tool or PowerTCP Emulation for .NET is common, as users wish to match previously existing terminals.
L
Listing
A Listing stands for a directory listing returned by an FTP server when a command is sent requesting directory information. PowerTCP products return directory information as a collection, with all the individual files represented as objects, making programmatic responses to directory information much easier to code. When finding directory structures that can't be parsed, the Listing object returns the directory data as a string for manual parsing.
Localization
Localization is the process of adapting a computer program for a specific international market. The PowerWEB TextBox for ASP.NET has been localized into French, German, and Spanish with support for custom localization using XML files.
LPK
An LPK file is a file that licenses and packages ActiveX controls when running on a Microsoft Internet Explorer Web Browser. This file must be created for all ActiveX components that require licensing, regardless of manufacturer. More information is available in the PowerTCP documentation and at Microsoft at http://support.microsoft.com/default.aspx?kbid=159923.
M
Mail WinForm Templates
WinForm templates are a set of forms created by Dart to assist developers in making interactive email applications. All the forms include source-code and are a great way of seeing how to build interactive email applications.
Managed Code
Managed code is code that targets the Microsoft CLR (Common Language Runtime), the foundation of the .NET Framework.
Message Object
The Message object transforms any Internet mail message into an object that you can easily manipulate within your program. Alternatively, any message that you build or modify can be quickly encoded and sent. The Message object is a core component of the SMTP control, the POP control, and the IMAP control. In Mail for .NET, the equivalent object is the MessageStream.
MessageStream
The MessageStream object is used within PowerTCP Mail for .NET and PowerTCP Secure Mail for .NET to represent a MIME (or non-MIME) Internet email message. The MessageStream object is used by the Smtp component to prepare and encode email messages, and by the Pop component to decode a received email message. When using the MessageStream object, message parts are always encoded/decoded "on the fly" (supported encoding types include Base64, Quoted Printable, UUEncode, and Yencode), which both increases the speed of processing and eliminates the use of temp files in encoding/decoding. Every MIME attachment, MIME part, and label element is accurately represented as an object.
MGET
A method to retrieve multiple files based on wildcards, file lists, or entire branches of a directory tree.
MIB
MIB (Management Information Base) is a database of network management information that is used by a network management protocol such as SNMP. MIB objects are organized in a tree structure that includes public (standard such as MIB I and MIB II) and private (proprietary) branches that are defined by device manufacturers. PowerTCP SNMP Tool products interpret MIB information in an object-oriented manner.
MIB Compression
MIB compression is a Dart technique to merge and encode numerous MIB files into a single encoded file using the PowerTCP MIB Compressor application. This technique enables a more efficient deployment and security mechanism for multiple MIB files, plus increases the speed of interpreting the MIB files.
MIME
The Multi-Purpose Internet Mail Extensions. The MIME protocol was created as an extension to the SMTP protocol as a way of storing more complex data, such as images, videos, applications, or any binary data, in an email message. Before MIME, only ASCII text based data could be part of an email message. MIME is detailed in RFC 1521 and 1522.
MPUT
A method to store multiple files based on wildcards, file lists, or entire branches of a directory tree.
Multi-threaded
A thread is simply defined as a single path of code that is being executed. A multi-threaded development environment is one that allows a single process to have multiple worker threads (in addition to the user-interface thread if the application is interactive) and provides context-switching between the threads. Such development environments include .NET, C++, and Delphi. Visual Basic 6 uses another technique called apartment-model threading where threads operate in their own apartment. This technique does little to separate it from a single threaded model as all requests are serialized through the Windows message queue, thus only a single apartment is accessed at a time.
N
Network Devices
A network device is any device that operates on a network such as a switch, printer, hub, router, or computer. Network devices often have associated SNMP agents that allow them to communicate with an SNMP manager.
Non-blocking
Non-blocking operations are methods that execute in Windows Forms applications without interfering with the User-Interface (UI).
Notification
See traps.
O
OID
OID (Object IDentifier) is a number that identifies an object's position in a global object registration tree. An example is 1.3.6.1.2.1.1.6, which corresponds to sysLocation, and identifies the location of the device. OIDs are prevalent in the SNMP protocol.
On-line Help
On-line help and dynamic help refer to the ability to bring up documentation within Visual Studio .NET by simply using the F1 key on any member or showing the associated member on the dynamic help window when the cursor moves over a member in the code window.
Optimized Algorithm
The PowerTCP Zip Compression Tool uses a high-performance compression algorithm that is intended to maximize compression speed for a majority of files. This technique is very helpful in web applications where server-side resources are at a premium.
Option Negotiation
Telnet uses options to describe what capabilities will be supported during a telnet session. Before using an option, the parties must negotiate to ensure that both ends support the option. This is done by exchanging "option code sequences."
P
Packet
Data that is sent across a network. Large blocks of data are often broken up into several packets and then reassembled at the destination. Packets often include checksum codes to detect transmission errors. The structure of a packet is determined by the protocol being used.
Part
A MIME message consists of one or more parts. An example is a text message with an attached file, which would contain two parts. When any file is attached to a message, the Content-Type in the main header becomes multipart, identifying it as a message with more than just text. Parts are included after the main header, separated by a boundary. Each part may be encoded with a different encoding scheme. Multiple parts are easy to implement using the PowerTCP Mail Tool's Message.Parts collection. Also, AddText, AddHtml, and AddAttachment methods facilitate the creation of multipart messages.
PCT
PCT (Personal Communications Technology) is an enhanced version of the original SSL specification.
Ping
Ping (Packet Internet Groper) is a protocol used for determining whether a machine is currently connected to the Internet. This is done by sending a packet to the host and waiting for a reply. The PowerTCP Winsock Tool includes a Ping control, and PowerTCP Sockets for .NET includes a Ping component.
Pipelining
Pipelining is an advanced mail mechanism that sends multiple commands to a server at once, rather than one-at-a-time. This technique increases the processing proficiency of mail commands.
PipeStream
A PipeStream is a stream class which pipelines data to/from another stream. When data is accessed from a PipeStream, it is actually read from/written to its internal, "contained" stream. Essentially, the stream acts as a "pipe", simply passing data through to the next stream. PipeStreams can be connected to perform numerous transformations on the data passing through. See "PowerTCP Secure Implementation Explained" in the PowerTCP SSL Sockets for .NET documentation for a detailed description of how PipeStream is used to provide services to PowerTCP for .NET products.
POP3
The Post Office Protocol. The POP standard that is commonly used today is based on RFC 1939 and is referred to as version 3, or POP3. This protocol is the most common mail download system, and is supported by the largest number of email clients. Outlook is a common POP client. A POP client connects to a POP server (such as Microsoft Exchange), and downloads the user's available mail.
POPS
The protocol used by POP clients that run over SSL. The PowerTCP SSL Tool and PowerTCP Secure Mail for .NET include controls that support POPS.
POST
An HTTP command to upload content to a server. This command is often used to send form data or files from a client to a server.
Private-key
A private-key is the secret part of a key pair in a public-key cryptographic mechanism. When a certificate request (CSR) is generated by a computer that wishes to receive an x.509 certificate for use in a public-key encryption system, both the private key and public key are generated. The certificate request contains the public-key which will be part of the certificate that is generated by a certificate authority (such as Verisign or Thawte) in response to the certificate request. During secure communications, the public key, which is available in the certificate, is used to encrypt the data, while the private key, which is only available on the machine that is the owner of the certificate, is used to decrypt the data. Certificates can be exported, along with their corresponding private-keys and any certificate authority certificates using the PFX export mechanism.
Property Builder
A design-time editor that allows the properties of a control to be set interactively, and changes the characteristics of the control in the designer (the visual non-code page that contains all the controls on a form) immediately. This allows for extensive changes to a control without writing any code, and is useful for proto-typing its look and feel.
Proxy
An intermediary application that is both a client and a server, and is dedicated to making requests on behalf of other clients. A proxy is often used as client-side portals through a network firewall, or as application that adds support for protocols not inherent to a client. When working with a network firewall, a proxy acts as a trusted application that will access the Internet on the client's behalf.
Public-key
Public-key is half of a key pair, the other being a private-key. A public key is contained within a digital certificate. A public key can encrypt data, however data encrypted with a public key can only be decrypted by the corresponding private key, which is kept by the owner. A public key can also be used to verify the authenticity of a digital signature. See Private-key.
PUT
An HTTP command to put content to a server. The command is often used to place files directly on a server. Most servers support the POST command for accepting data instead of PUT. A POST request is used when uploaded data is to be handled by a known resource, while a PUT request could be directed at a resource which does not (yet) exist. Also, the POST command is used in response to a form, while the PUT method can only contain a single data item. The PUT method is suited for publishing pages.
Q
QuickSend
This SMTP related method is designed to send mail messages in one line of code by specifying all the needed information to create a valid message using parameters such as To, From, Subject, Text, etc. For more complex messages, the Send method is used in conjunction with the Message object.
QuickUnzip
A short-cut method that allows files to be decompressed using a single line of code, rather than specifying the properties that configure a zip operation and manipulate the collection. The downside of using a short-cut method is that customization is limited, as all the properties are set to default values.
QuickZip
A short-cut method that allows files to be compressed using a single line of code, rather than specifying the properties that configure a zip operation and manipulate the collection. The downside of using a short-cut method is that customization is limited, as all the properties are set to default values.
R
Reference Guide
The reference guide of a help file outlines and defines all the members of a component or control.
Request
An HTTP request is a message sent by a web client to a web server requesting a resource or providing information. Common resource requests are for HTML pages. A request often takes the form of a command, such as GET, PUT, or POST. The PowerTCP WebServer Tool includes a Request object that enables developers to manage how the server will respond to the request.
Response
An HTTP response is a message sent by a web server in response to a request sent by an HTTP client. A response can be HTML and JavaScript code that constitutes a web page. The PowerTCP WebServer Tool includes a Response object that enables developers to customize the server response.
Rexec
Rexec (Remote Execution) executes a single command on a remote server. This requires that a rexec service or daemon be present on the remote server. An example usage is starting scripts on a remote server. The PowerTCP Emulation and Telnet Tools, plus the PowerTCP Telnet for .NET and Emulation for .NET Tools include this capability.
Rlogin
Rlogin is a program that provides a terminal interface between hosts (usually UNIX) using the TCP/IP network protocol. Unlike Telnet, Rlogin assumes the remote host is, or behaves like, a UNIX machine. The PowerTCP Emulation and Telnet Tools, plus the PowerTCP Telnet for .NET and Emulation for .NET Tools include this capability.
Royalty Free
Royalty free usage refers to a license that does not require royalty payments for products distributed using PowerTCP Tools or PowerTCP for .NET technology. PowerTCP is licensed on a per developer basis with a development environment fee, but no fee on the users of an application developed with PowerTCP Tools or PowerTCP for .NET products. There are specific exceptions so please read the license agreement for details.
Rsh
Rsh is a program that provides a means of executing commands on a remote host without the need to login, as the user is verified based on the host IP. The PowerTCP Emulation and Telnet Tools, plus the PowerTCP Telnet for .NET and Emulation for .NET Tools include this capability.
S
S/MIME
S/MIME (Secure / Multipurpose Internet Mail Extensions) is a standard for public key encryption and signing of e-mail encapsulated in MIME.
Sample Project
A sample project is an application built by Dart Communications that demonstrates a feature or set of features. These applications ship with their respective products and users are licensed to modify and use the code from these applications in their projects. Note that the sample applications are provided as-is, and may require further coding if intended for actual use.
Screen-scraping
The act of programmatically parsing the characters returned from a server in order to take some sort of action based on the data returned.
Scripting
A sequence of commands in a shell-executable file is called a script. Scripting does not require user-interaction.
Scripting Language
A simple programming language, such as VBScript, that enables Web page designers to enhance the look of, or add functionality to, a Web page using such technologies as ASP. Scripts can also be written to execute operating system processes using Windows Scripting Host. Scripting applications are not event driven and must be written in a synchronous fashion.
Scroll-back Buffer
As data is displayed in the VT control, the screen will scroll, preserving the data from previous pages in a buffer that can be easily accessed.
Secure File Transfer
HTTPS: Secure file transfer refers to uploading and downloading files when using the HTTPS protocol, which assures that the transmission is encrypted and the user authenticated. FTPS: Secure file transfer refers to uploading and downloading files when using the FTPS protocol, which assures that the transmission is encrypted and the user authenticated.
Secure FTP Server
An FTP server that allows for secure file transfers by encrypting the files sent/received and authenticating any clients. The PowerTCP SSL Tool includes a control that provides this capability.
Secure Server
A server that is designed to not only handle client requests, but also encrypt data and authenticate both itself and its clients. The PowerTCP SSL Tool and PowerTCP SSL Sockets for .NET include controls that provide these capabilities.
SegmentedStream
SegmentedStream provides a means for reading a segment of bytes from a backing store, such as a network socket or file. To improve performance, the SegmentedStream buffers read and write operations to the underlying stream, and provides asynchronous read and write capabilities. The SegmentedStream object is used within PowerTCP for .NET products to read/write network data.
Self-extraction
Self-extraction is the ability to create a compressed file that can decompress itself without the need of a decompression application. The file extension of a self-extracting file is .exe and the file operates like a normal executable.
Server
A server is an application that provides a specific kind of service to client applications running on the same or other computers. Examples of server applications include FTP servers, Web servers, Telnet servers, POP servers, SMTP servers, IMAP servers, plus other custom servers designed to meet proprietary needs. Multiple server applications can reside on a single computer. The PowerTCP Server Tool and PowerTCP Sockets for .NET include controls that enable developers to build such applications. The PowerTCP SSL Tool and PowerTCP SSL Sockets allow for the creation of secure versions of such applications.
Server-side Authentication
Server-side authentication is when a client examines the server certificate before secure communications commences. This assures that the server is not an imposter.
Session
A series of transactions from a single user. If a pre-determined period of time has elapsed between activity from a single user, a new session is considered started. PowerTCP WebServer Tool includes a Session object that enables developers to write code that is session dependent.
Skin
An alternative graphical interface for a software program. A skin customizes the look of a program but does not change its functionality. Programs that use skins normally include a standard for creating custom skins. The PowerWEB TextBox for ASP.NET supports skinning.
SMTP
The Simple Mail Transfer Protocol. This common mail protocol is used for sending mail messages across the Internet. This protocol is based on RFC 821. An SMTP client will connect and send messages to an SMTP server. The server is then responsible for relaying mail to its final destination. An example of an SMTP client is Outlook and an example of an SMTP server is Microsoft Exchange.
SNMP
SNMP (Simple Network Management Protocol), is a UDP-based protocol for communication between devices on a network, such as routers, printers, and personal computers. A device is SNMP compatible if it can be monitored and/or controlled using SNMP messages, otherwise known as PDU's (Protocol Data Units). Devices that are SNMP compatible contain SNMP agent software to receive, send, and act upon SNMP messages. Software that communicates with agents are called managers. PowerTCP SNMP Tool products enable the development of custom agent and manager applications.
SNMP Agent
An SNMP agent is an application, often built into a network device, that communicates with SNMP managers. Usually agents respond to get and set messages from managers, but agents can also send out unsolicited information, or traps, to listening managers. PowerTCP SNMP Tool products enable the development of custom agent and manager applications.
SNMP Manager
An SNMP manager is an application that communicates with SNMP agents. Managers get and set agent variables, as well as receive unsolicited trap messages from agents. PowerTCP SNMP Tool products enable the development of custom agent and manager applications.
SNMP Message
An ASN.1 encoded message sent between an SNMP agent and an SNMP manager.
SNMP Table
An SNMP Table is the only means of structuring data in SNMP. Columns represent variables, whereas rows are table entry instances that contain values for each column.
SNMP Trap
Message sent by an SNMP agent to a manager to indicate the occurrence of a specifically defined condition or a threshold was reached. SNMPv2 refers to traps as notifications.
SnmpMessage
The SnmpMessage object performs complex encoding and decoding of SNMP messages. Received messages, when decoded, populate an SnmpMessage object that the developer can easily manipulate. Conversely, the developer can use the SnmpMessage object to easily encode well-formed messages that are ready to send over the network.
SnmpTable
The SnmpTable object is intended to work with information that follows the SNMPv2 table format. All objects with OIDs subsidiary to the OID passed in are assumed to be part of the table. Table columns are defined as objects in the mib, whereas rows are instances of column variables.
SnmpTrap
The SnmpTrap object provides an easy way to manage trap information. The object is similar to the SnmpVariable object, but with trap-specific properties.
SNMPv1
Version 1 of the SNMP specification. SNMPv1 is a simple request/response protocol. In SNMPv1 the manager issues a request, and the agents return a response.
SNMPv2
Version 2 is an evolution of version 1. The Get, GetNext, and Set operations used in version 1 are the same as in version 2. However, version 2 adds and enhances some protocol operations. For example, the trap operation serves the same purpose, but uses a different format for the message and the GetBulk and Inform operations have been added. Version 2c is the most common revision of SNMPv2.
SNMPv3
Adds private key encryption to what is basically SNMPv2 functionality.
SnmpVariable
The SnmpVariable object exposes properties such as OID and value, providing an easy way to manage SNMP variables.
Spanning
Spanning is the ability to separate a single zip file into multiple parts and place them on removable media or a hard drive.
SSL
SSL (Secure Sockets Layer) is a technology used on networks and the Internet to secure transactions (such as web requests or file transfers) by means of public key cryptography. A secure communications channel is established between the server and the client with all data encrypted. Digital signatures are used to verify data integrity, and trust in a client or server is confirmed by using digital certificates signed by a Certificate Authority called a "trusted third party". The encryption strength used in SSL is 40-bit and 128 bit.
SSL2
Version 2.0 of the SSL specification.
SSL3
Version 3.0 of the SSL specification.
SslStream
A stream class that handles bi-directional SSL transformations. The SslStream class controls encryption/decryption and certificate authentication. By using this class between a TCPStream and a higher-level protocol stream, SSL security is enabled.
Stream
A stream is an abstract object that can be read from or written to. Typically, the stream delivers bytes to a buffer (using Read()) or takes bytes from a buffer (using Write()). The stream's end point could be another stream, a file, memory, or data socket (among others)
Stream-based Design
An architectural model based on streams, with the ability to read/write stream-derived classes through interface members. All PowerTCP for .NET products use a stream-based design for maximum extensibility.
Style Information
Style information is the descriptive information of a VT-displayed character, presented as an escape sequence.
SymmetricCryptoStream
This class is useful for providing private key encryption, simplifying Microsoft's implementation. This class can be initialized with a TcpStream instance (for encrypting data to be sent over the network), a FileStream instance (to encrypt a file), or with any other type of Stream. Any .NET symmetric algorithm can be used with this class.
Synchronous
Synchronous, or blocking execution refers to a program that will not execute the next line of code until the current function call has completed. This is common in scripting applications that lack mechanisms for events or callbacks. Blocking operations can also be easier to program as notification is not required when an operation completes. PowerTCP products offer both blocking and non-blocking operations.
T
Table Wizard
An interactive dialog that allows for a table to be defined, and its settings to be translated into HTML table tags. The PowerWEB TextBox for ASP.NET includes a Table Wizard.
Tag
Tag often refers to an HTML tag on a web page or an .aspx page. A tag is code that is used in HTML documents to indicate elements. Elements are enclosed in opening and closing tags. For example,

and

indicate that anything between the

tags correspond to a separate paragraph.

TCP
TCP/IP(Transmission Control Protocol) is the basic communication language or protocol of the Internet, and guarantees byte ordering and integrity of data sent and received. It can also be used as a communications protocol in a private network (either an intranet or an extranet). Other protocols are often built on top of the TCP protocol. Examples include FTP, Telnet, SMTP and HTTP. TCP is built upon IP(Internet Protocol) and is often referred to as TCP/IP. The PowerTCP Winsock Tool includes a TCP control, and PowerTCP Sockets for .NET includes a TCP component.
TCP Server
A server that just manages connections without an upper-layer protocol logic such as HTTP, FTP, SMTP, etc implemented. A TCP server would be used to build a protocol specific server. See Server.
TCPS
TCP running over SSL. This provides encryption and authentication over the standard TCP connection. The PowerTCP SSL Tool and PowerTCP SSL Sockets for .NET include controls providing this capability.
Telnet
Telnet is a protocol for remote computing on the Internet. This protocol permits a computer to act as a terminal for a remote machine. The remote host accepts input directly from your computer as it is typed, and session output is directed to your screen. The PowerTCP Emulation and Telnet Tools, plus the PowerTCP Telnet for .NET Emulation for .NET Tools include Telnet components.
TEXTAREA
The TEXTAREA element on a web page indicates a multi-line text entry field.
Thread-safe
The technique of writing code that prevents multiple threads from concurrently accessing a block of code. PowerTCP for .NET products provide thread-safety around critical members (members that are using non-sharable resources), but other members are not thread-safe.
TLS
TLS (Transport Layer Security) is designed as a successor to SSL and uses the same cryptographic methods but supports more cryptographic algorithms. Often times TLS is referred to as SSL 3.1.
TrueType
True Type fonts are the most popular fonts used in the Windows operating systems. Their scalable nature allows them to be both displayed on screen at small sizes, and used for printing at high resolutions, without significant loss of quality.
TTY
An early form of terminal communications that does not use any escape sequences to define characters. The PowerTCP Emulation Tool and PowerTCP Emulation for .NET include controls that allow developers to build applications that support TTY.
U
UDP
UDP/IP(User Datagram Protocol) is a stateless protocol in that UDP makes no provision for acknowledgment of packets received. UDP does not require the sender and receiver to establish a connection before data is transmitted. The protocol is considered unreliable because there is no specification for the order in which sent datagrams will arrive, or whether they will arrive at all. To assure reliability, it's up to the application using UDP to provide it, or to alternatively use the TCP protocol. The PowerTCP Winsock Tool includes a UDP control and PowerTCP Sockets for .NET includes a UDP component.
URL Cracking
URL cracking is a technique for splitting a complete URL into separate parts. A URL such as www.dart.com/dotnet/helloworld.asp can be cracked into just the domain, which is www.dart.com, the directory, which is dotnet/, and the requested file, which is helloworld.asp.
V
VT
A terminal emulation program that makes a workstation appear to be a dumb terminal connected to some remote system, such as a mainframe. The PowerTCP Emulation Tool and PowerTCP Emulation for .NET include controls that allow developers to build such applications.
VT100
An ASCII terminal manufactured by Digital Equipment Company (DEC) that was popular in the 1960s and 1970s, and primarily used with Unix and other non-IBM systems. Since almost every computer made could recognize and work with a VT100 terminal, all terminal emulation products designed to work with non-IBM computers offer VT100 emulation as a basic emulation. The PowerTCP Emulation Tool and PowerTCP Emulation for .NET include controls that allow developers to build such applications.
VT220
An ASCII terminal called the DEC VT220 Video Terminal. Specific escape code sequences are defined by the VT220 specification, which includes some multi-national character support. The PowerTCP Emulation Tool and PowerTCP Emulation for .NET include controls that allow developers to build such applications.
VT320
An ASCII terminal called the DEC VT320 Video Terminal. Specific escape code sequences are defined by the VT320 specification, which includes extended multi-national character support. The PowerTCP Emulation Tool and PowerTCP Emulation for .NET include controls that allow developers to build such applications.
VT52
An ASCII terminal called the DEC VT52 Video Terminal. Specific escape code sequences are defined by the VT52 specification. The PowerTCP Emulation Tool and PowerTCP Emulation for .NET include controls that allow developers to build such applications.
W
WaitFor
This method reads from the data stream until the specified string is found or the method times out. For example, during a login operation, the client will send a username after receiving a "login:" prompt from the server. The WaitFor method could be used to continue reading data until the prompt was found.
Web Form
A Web page or portion of a Web page that is filled out by the user and sent back to the server for processing.
Web Server
An application that serves Web pages or files to Web clients using the HTTP protocol. The PowerTCP WebServer Tool is designed to enable developers to build their own custom web servers.
WebASP
The WebASP component is a WinInet-independent HTTP client component that is part of the PowerTCP Web Enterprise product. The component also includes extra support for multi-file uploading.
Wildcard
Characters used in a search that can match any character or string of characters. Wildcards can be used to match patterns or words. An example would be "*.doc" which means all the files with a ".doc" extension.
Windows Service
The Microsoft technology that allows applications to operate as services on the Windows NT, 2000, XP, and 2003 platforms. The PowerTCP Server Tool, PowerTCP SSL Tool, PowerTCP SNMP Tool products, and the PowerTCP WebServer Tool include a service control that simplifies the development of service applications. PowerTCP .NET products do not include a service control as the technology is built into the .NET Framework.
WinInet
The Windows Internet (WinInet) application programming interface (API) is a set of functions that enables applications to interact with Gopher, FTP, and HTTP protocols to access the vast resources on the Internet. Microsoft Internet Explorer uses WinInet as the core HTTP engine. Microsoft does not recommend that applications using WinInet operate in a scripting environment such as ASP. The advantage of WinInet is that it does encapsulate such features as NTLM authentication, a proprietary Microsoft authentication mechanism. The PowerTCP Web Tool uses a component that is calls into WinInet, while the PowerTCP Web Enterprise Tool includes both a WinInet independent component and the WinInet-based component available in the PowerTCP Web Tool.
Wrapper Class
A class that wraps a component, providing easier use or value-added functionality. PowerTCP Tools include wrapper classes for C++ that alleviates the challenges of using ActiveX components in the C++ development environment. Other environments, such as Delphi and .NET, create wrappers automatically.
WYSIWYG HTML Editor
A WYSIWYG (What You See Is What You Get) editor that allows a web page to be created in a manner that matches the final visual presentation, compared to using HTML tags that do not have a visual representation until rendered by a browser.
X
XHTML
XHTML is an extension of HTML 4.0 that includes support for XML and thus includes a requirement for well-formed tags (all open tags requiring a close tag).
Y
Y-encode
Otherwise known as yEnc format, this is a relatively new 8-bit encoding type popular in Usenet.
Z
Zero-code Customization
The ability to customize a control just using the Property Builder. Tags are auto-generated by the environment.
ZipLite
A scaled-down version of the PowerTCP Zip Compression Tool that is designed for simple compression and decompression operation.