- Network topology refers to the arrangement of computers, transmission media and other network components. There are THREE (3) common types of topologies which are bus, ring and star.
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As regard to the types of topology above, of course there is pros and cons for each of them. Here are some;
Bus: This network topology is very easy to set-up and extend. Plus, the cable length required is the least as compared to the other networks. It required a small cost and very good for LAN.
Ring: All data flows just in one direction, hence reducing the chance of packet collisions. The data transfer between workstations is at high speeds, but no network server is needed to control the network connectivity between each workstation. Additional workstations can be added without impacting performance of the network.
Star: Easy to install and wire. When connecting or removing devices, no disruptions to the network will occur. It is easy to detect faults and to remove parts. It has centralized management where this could help in monitoring the network.
Bus : The central cable length and number of nodes that can be connected is limited. Say that if the main cable (i.e. bus ) encounters problem, whole network breaks down. When network goes down, it is hard to identify the source of problems; which computer is problematic. The more devices connected, the more traffic will be the network. Hence it is not suitable for networks with heavy traffic. Other than that, security is very low because all the computers receive the sent signal from the source.
Ring : All data being transferred over the network must pass through each workstation on the network. In repercussion, this make the data transfer speed slower. If one workstation shuts down, the entire network will be impacted. The hardware needed to connect each workstation to the network is also expensive.
Star: If the central device fails, the whole network will goes down. The use of hub, a router or a switch as central device increases the overall cost of the network. Performance and as well number of nodes which can be added in star topology is depend on capacity of central device.
posted by: eMii_
4. Transmission media comprised of the physical system that data takes to flow between devices on the network. There are THREE (3) types of transmission media which are coaxial, twisted pair and fiber optic. Briefly describe the differences between these 3 types transmission media. Additionally, please explain the differences between shielded twisted-pair (STP) and unshielded twisted pair(UTP) cable.
Differences of three type of Fiber optic,Coaxial cable and twisted pair:
TWISTED PAIR COAXIAL CABLE FIBER OPTIC
(1)Low cost (1)Moderate Cost (1)High cost
(2)Best for short (2)Moderate distance (2)Long distances
distance(330 ft) (3300 ft-thin) (14256 ft)
(3)Easy to install (3)Professional installation (3)Professional installation
(4)Low security (4)Average security (4)High security
(5)Low resistance to (5)Moderate resistance to (5)Very high resistance
interference interference to interference
Differences between shielded twisted-pair (STP) and unshielded twisted pair(UTP) cable.
Twisted pair(STP) Unshielded twisted pair(UTP)
(1)Has a metal foil covering (1)Does not have metal foil covering
(2)Gives better resistance to (2)Does not provide better resistance
electromagnetic interference as compared to electromagnetic interference as
to UTP compared to STP
(3)Grounding is possible (3)Grounding is not possible
(4)Possibility of crosstalk is less as it resisted (4)Possibility of crosstalk is more
to EMI as it provide less resistance to EMI
(5)Distance travelled is large and can be used (5)Distance travelled is less and
in MAN used in LAN
(6)STP is little expensive than UTP (6)UTP is much cheaper than STP
POSTED BY:UMAR RAZIF
6. There are three important network navigation devices which are switches, bridges,
routers. These devices are responsible to make sure that each packet sent through the
network arrive to its destination. Describe how switches, bridges and routers differs from each other in terms of their functionalities.
–A router essentially determines which way is the shortest or fastest in a network, and routes packets accordingly. It works at layer 3 of the OSI model, moving packets from one port to another based on L3 addresses – ie. IP addresses, IPX addresses, etc.
A switch connects one point to another in a network temporarily by turning it on and off as necessary. It works at layer 2, with some intelligence (there are also some layer 3 switches, that essentially have routing capabilities).
A bridge connects one point to another in a network. It works at layer 1 and 2 of the OSI model. It only connects two segments of the network.
A bridge and a switch are very similar. In practice, a switch can be looked at as a multiport bridge – both have the same basic functionality. They move frames between ports based on Mac addresses. A lot of functionality canr be added to switches, but the base purpose is the same. “Layer 3” switches can be looked at as a switch with a router inside.
posted by: Houssam Eddine Benkheira
7. Network administrators are responsible to administer the security of a network. Enlist what should be done by a network administrator to keep the network secure?
In order for network administrators to keep the network safe, there are few measures to be taken. These lists are a few measures that could be implemented on:
- Use encryption on your wireless access points (AP)
Encryption defines as the process of converting information or data into a code, especially to prevent unauthorized access. The best solution is to use WPA2 encryption which is better than any encryption methods that easily broken into.
- Hide your SSID (service set identifier)
This is to avoid other to be able to hack into your wireless connection.
- Disable unauthorized access from the outside network through a build of Firewall.
Have firewall to block unauthorized access.
- Make sure that every node use antivirus software.
To avoid the plantation of virus in the network or nodes which can eventually lead to hack of data.
- Use authentication ID and password.
This is to screen the user and track the daily usage of the user. Besides, implement the access privilege to restrict the area of access between network users.
- Implement the physical protection measures.
Physical measures such as user access card or biometric authentication security to avoid outsider to be able to access to the business’s data and information.