S - T

Glossary: S - T


This protocol is similar to the File Transfer Protocol (FTP); however, as well as files, SMB allows you to share devices like printers.

  • Port 445


Short for Search Engine Optimization, which is the process of improving the quality and quanitity of traffic to a website or web page from search engines. This method targets unpaid traffic results, referred to in digital marketing as "organic" traffic or results.

Source Port

This value is the port opened by the sender to send the TCP packet from. This value is chosen randomly (out of the ports from 0-65535 that aren't already in use at the time).

SQL Injection

SQL injection is a code injection technique used to attack data-driven applications, in which malicious SQL statements are inserted into an entry field for execution (e.g. to dump the database contents to the attacker).


This protocol is used to securely login to systems via a text-based interface for management.

  • Port 22


A SYN message is the initial packet sent by a client during the handshake. This packet is used to initiate a connection and synchronise the two devices together


This packet is sent by the receiving device (server) to acknowledge the synchronisation attempt from the client.


TCP (or Transmission Control Protocol for short) is another one of these rules used in networking.This protocol is very similar to the OSI model that we have previously discussed in room three of this module so far. The TCP/IP protocol consists of four layers and is arguably just a summarised version of the OSI model. These layers are:

  • Application
  • Transport
  • Internet
  • Network Interface

Time to Live (TTL)

This field sets an expiry timer for the packet, so it doesn't clog up your network if it never manages to reach a host or escape