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LPT Ports - Parallel Direct Cable Connection - Pinouts - Transfer speeds

Posted in Network Cabling

LPT Ports - Parallel Direct Cable Connection - Pinouts - Transfer speeds - 4.1 out of 5 based on 8 votes

LPT Ports - Parallel Direct Cable Connection - Pinouts - Transfer speedsThe Parallel Direct Connection is the second solution covering the transfer of data from one computer to another. The cable required is slightly more complicated as it has more wires that need to be connected, but the transfer speeds achieved make it well worth the time and effort required to make the cable. We'll also take a look at physical LPT ports, LPT modes (SPP, EPP, ECP), LPT port Pintouts, LPT direct connection cable and more.

Users interested in transferring files using parallel direct cables can visit the following Microsoft support page which explains How to Install and Configure the Direct Cable Connection Feature (https://support.microsoft.com/en-us/kb/298446).

As we’ll see further below, there are three different type of LPT ports, SPP, EPP and ECP, each supporting different speeds and features, but all use the same direct cable connection.

A standard LPT port will provide speeds of 40Kb/s to 60Kb/s while the faster ECP ports will deliver up to 1.1 Mb/sec or 8.8 Mbps.

To better understand why parallel links are much faster than serial links, we’ll need to analyze the way data is transferred. This is clearly shown and explained in the diagram below:

Transfer of Data via Parallel (LPT) Port

Figure 1. Transfer of Data via Parallel (LPT) Port

This diagram shows data transfer via parallel ports and we can see multiple data blocks being simultaneously transferred from one host to another, increasing significantly the overall throughput. Serial ports are capable of transferring one data block per time, therefore unable to match speeds of parallel ports.

What does the parallel port (LPT) look like?

Introduction To Protocols

Posted in Network Protocols

Introduction To Protocols - 3.6 out of 5 based on 21 votes

In the networking and communications area, a protocol is the formal specification that defines the procedures that must be followed when transmitting or receiving data. Protocols define the format, timing, sequence, and error checking used on the network.

In plain english, the above means that if you have 2 or more devices e.g computers which want to communicate, then they need a common "Protocol" which is a set of rules that guide the computers on how and when to talk to each other.

The way this "defenition" happens in computer land is by the RFC's (Requests For Comments) where the IETF (a group of enginners with no life) make up the new standards and protocols and then the major vendors (IBM, Cisco, Microsoft, Novell) follow these standards and implement them in their products to make more money and try to take over this world !

There are hundreads of protocols out there and it is impossible to list them all here, but instead we have included some of the most popular protocols around so you can read up on them and learn more about them.

The table below shows the most popular TCP/IP protocols. The OSI model is there for you to see which layer each of these protocols work at.

One thing which you should keep in mind is that as you move from the lower layers (Physical) to the upper layers (Applications), more processing time is needed by the device that's dealing with the protocol.

          osi-tcp-ip     protocols-osi

Following are the protocols analysed on Firewall.cx:

UDP Protocol - Header

Posted in Network Protocols

UDP Protocol - Header - 4.1 out of 5 based on 15 votes

This article covers the UDP protocol. We examine the structure of the UDP header, the protocols that use UDP as a transport plus a lot more.

Some common protocols which use UDP are: DNS, TFTP, ARP, RARP and SNMP.

When people refer to "TCP/IP" remember that they are talking about a suite of protocols, and not just one (as most people think). TCP/IP is NOT one protocol. Please see the Protocols section for more information.

The User Datagram Protocol (UDP) is defined by IETF RFC768

File Transfer Protocol - FTP

Posted in Network Protocols

File Transfer Protocol - FTP - 4.1 out of 5 based on 11 votes

::panel_article:: ::/panel_article::

File transfer is among the most frequently used TCP/IP applications and it accounts for a lot of the network traffic on the Internet. Various standard file transfer protocols existed even before the Internet was available to everyone and it was these early versions of the file transfer software that helped create today's standard known as the File Transfer Protocol (FTP). Most recent specifications of the protocol are listed in RFC 959.


Trivial File Transport Protocol - TFTP

Posted in Network Protocols

Trivial File Transport Protocol - TFTP - 3.7 out of 5 based on 7 votes

TFTP is a file transport protocol and its name suggests it's something close to the FTP protocol (File Transfer Protocol), which is true .. to a degree. TFTP isn't very popular because it's not really used on the Internet because of its limitations which we'll explore next.


The Protocol

TFTP's main difference from FTP is the transport protocol it uses and the lack of any authentication mechanisim. Where FTP uses the robust TCP protocol to establish connections and complete the file transfers, TFTP uses the UDP protocol which is unsecure and has no error checking built in to it (unless they have implemented some type of error checking in the program you are using to transfer files), this also explains why you are more likely to find TFTP in a LAN, rather than a WAN (Wide Area Network) or on the Internet.


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