3.1.1 - Identify different types of networks.
3.1.2 - Outline the importance of standards in the construction of networks.
3.1.3 - Describe how communication over networks is broken down into different layers
3.1.4 - Identify the technologies required to provide a VPN. 3.1.5 - Evaluate the use of a VPN.
Basics of Networking:
Notes: 3.1.1
local area network (LAN), A network of interconnected computers in a limited space such as a home or an office.
virtual local area network (VLAN), Is a LAN network that is virtulized using software and it allows computers to connect to each other.
wide area network (WAN), A network of computers interconnected in a large space, this is like a private internet.
storage area network (SAN), A network that is dedicated to making storage arrays and storage disks.
wireless local area network (WLAN), A LAN network that uses wireless infrastructure.
internet, extranet,
virtual private network (VPN), A Virtual Private Network that acts like a LAN allowing computers to connect to each other within the VPN. VPN technology relies on the internet to create this network
personal area network (PAN), Is a network of interconnected devices in a very small area. (example Bluetooth)
peer-to-peer (P2P).A network of interconnected computers over a network which doesn't use the internet it only relies on the client computers.
3.1.2
Standards enable compatibility through a common “language” internationally
Standards enable interoperability between different hardware and software configurations or makes.
Standards reduce ambiguity in information relay. They create an environment where only one thing is correct.
Physical-Electrical impulse through the network at the electrical and mechanical level. It provides the hardware means of sending and receiving data on a carrier, including defining cables, cards and physical aspects.
Data Link-At this layer, data packets are encoded and decoded into bits. The data link layer is divided into two sub layers: The Media Access Control Mac layer and the Logical Link Control (LLC) layer. The MAC sub layer controls how a computer on the network gains access to the data and permission to transmit it. The LLC layer controls frame synchronization, flow control and error checking.
Network-This layer provides switching and routing technologies, creating logical paths, known as virtual circuits, for transmitting data from node to node.
Transport-This layer provides transparent transfer of data between end systems, or hosts and is responsible for end-to-end error recovery and flow control. It ensures complete data transfer.
Session-This layer establishes, manages and terminates connections between applications.
Presentation-This layer provides independence from differences in data representation (e.g.encryption) by translating from application to network format, and vice versa.
Application- Everything at this layer is application-specific and supports application and end-user processes.
Several network protocols have become popular as a result of VPN developments:
PPTP
L2TP
IPsec
SOCKS
These protocols emphasize authentication and encryption in VPNs. Authentication allows VPN clients and servers to correctly establish the identity of people on the network. Encryption allows potentially sensitive data to be hidden from the general public. Many vendors have developed VPN hardware and/or software products. Unfortunately, immature VPN standards mean that some of these products remain incompatible with each other.
3.1.1 - Identify different types of networks.
3.1.2 - Outline the importance of standards in the construction of networks.
3.1.3 - Describe how communication over networks is broken down into different layers
3.1.4 - Identify the technologies required to provide a VPN.
3.1.5 - Evaluate the use of a VPN.
Basics of Networking:
Notes:
3.1.1
3.1.2
http://www.tcpipguide.com/free/t_InternationalNetworkingStandardsOrganizations.htm
3.1.3
Awareness of the OSI seven layer model is required, but an understanding of the functioning of each layer is not.
(Ref: http://www.webopedia.com/quick_ref/OSI_Layers.asp)
YouTube clip about the Seven Standards:
3.1.4
http://www.vpnc.org/vpn-technologies.html
Technology Behind VPNs
Several network protocols have become popular as a result of VPN developments:- PPTP
- L2TP
- IPsec
- SOCKS
These protocols emphasize authentication and encryption in VPNs. Authentication allows VPN clients and servers to correctly establish the identity of people on the network. Encryption allows potentially sensitive data to be hidden from the general public.Many vendors have developed VPN hardware and/or software products. Unfortunately, immature VPN standards mean that some of these products remain incompatible with each other.
3.1.5
The use of a VPN has led to changes in working patterns.
Some advantages of using VPN:
http://www.ibvpn.com/blog/2010/02/8-advantages-of-using-vpn/
-cost savings
-scalability
-security
-compatibility with broadband technology
Some disadvantages of using VPN:
- its deployment requires a high-level of knowledge and understanding of such factors as public network security-its availability and performance are difficult to control. Typically,VPN speeds are much slower than those experienced with a traditional connection.-two way calling-support issues-encryption-increased downtime
http://askhideki.com/advantages-and-disadvantages-of-using-vpn/
http://compnetworking.about.com/od/vpn/f/vpn_benefits.htm
Further reading about VPN's: