This document discusses firewall security in computer networks. It begins by defining firewalls as hardware, software, or a combination used to prevent unauthorized access to private networks or computers. It then summarizes the differences between hardware and software firewalls. The document goes on to explain how software firewalls work by inspecting packets of data. The rest of the document discusses wireless mesh networks, including routing protocols, standards, network architecture, advantages, and disadvantages.

1. FIREWALL SECURITY IN
COMPUTER NETWORK

2. Hon. Shri. BaBanrao Pacpute Vichardhara Trust's Parikrama
College of Engineering, Kashti , Shrigonda Ahmednagar.
Seminar Presentation
On
 Wireless Mesh Network
FIREWALLS SECURITY IN COMPUTER NETWORK
BY
Mayur Bankar
Guide
Miss.Kanade mam

3. Introduction
 Is hardware, software, or a combination of both
used to prevent unauthorized programs or Internet users from accessing a
private network and/or a single computer.

4. Chann Hardware vs. Software Firewalls ment
Scheme
 Hardware Firewalls
Protect an entire network
Implemented on the router level
Usually more expensive, harder to configure
Software Firewalls
Protect a single computer
Usually less expensive, easier to configure

5. DeHow does a software firewall work?
fination
 Inspects each individual “packet” of data as it arrives
at either side of the firewall
 Determines whether it should be to pass through or if it should be
blocked allowed to p

6. Dynamic Allocation

7. Routing tree construction
 The basic tree construction process uses the metric by each WMN
node to determine a parent to achieve better load balancing , and
load-aware channel assignment.
 Gateway is used as central node which pass maximum traffic and it
pass the information to its directly connected node by sending
advertisement message and this advertisement message consists of
costs directly connected node.
 Other node which can receive the advertisement message can join
or leave the node. If the new node has less cost the old node then it
can join the new node and leave the old node. In this way shortest
path is selected from source to destination.

8. Hybrid channel Allocation
 Both static and dynamic allocation have their own
advantages and disadvantages so we use hybrid architecture
which is combination of both , to can achieve better
adaptively compare to the pure static architecture without
much increase of overhead compare to the pure dynamic
architecture.

9. Bfs-ca(breadth first search channel
Assignment)
 represent edges between mesh radios instead of edges between
mesh routers which overcome the problem of both the fixed and
dynamic channel allocation scheme. This scheme is based on
interference – Aware channel assignment algorithm improved the
capacity of wireless mesh network by making use of all available
non-overlapping channels. This algorithm is based on an extention
to the conflict graph called the multi radio conflict graph(MCG).

10. Multi radio
 Mesh router can be equipped with multiple radios to perform
routing and access functionalities. This enables separation of two
main type of traffic in the wireless domain.
 Mesh routers improves the capacity of the network.
 Mesh radios help to mesh routers to send data to other nodes by
using different frequency.

11. Multi-channel
 In WMNs multi-channel concept is used with multi-radio to
improve the capacity of network.
 By using multi radios every radio can be connected with numbers of
different channels.
 In this way number of non overlapping channel increases and
reduce the channel interference. Data can be send on different
channels without overlapping.

12. Routing Protocols
 A routing protocol specifies how routers communicate with each other ,
disseminating information that enables them to select routers between
any two nodes on a computer network. Routing algorithm determine the
specific choice of route. Each router has a prior knowledge only of
networks attached to it directly.
 Types Of Routing Protocols
 1.DSR
 2.AODV
 3.MR-LQSR

13. DSR-Dynamic source routing protocol
 This protocol is based on the concept of source routing. The mobile
nodes are required to maintain caches that contain source routes of
which it is aware. The entries in the route cache are continually
updated as new routes are learned.

14. WMNS Standards
• IEEE 802.16a WMAN Mesh
• mesh mode in addition to the point-to-multipoint
(PMP) mode defined in IEEE 802.16.
• Operating in the licensed and unlicensed lower
frequencies of 211 GHz, allowing
non-line-of-sight (NLO) communications, spanning
up to a 50 km range.
• Supporting multi hop communications.


15. WMNs Standards
• 802.11s WLAN Mesh
• Multi-hop capability added to 802.11g/a/b
• Auto configure on power up
• Multi-channel multi-radio operation
• Topology discovery
• MAC Path selection protocol
• Modified forwarding for QOS and mesh control


16. Network Architecture
• WMNs consist of two types of nodes Mesh Routers
and Mesh Clients
• Mesh router
• Additional routing functions to support mesh
networking.
• Multiple wireless interfaces with same or
different wireless access technologies.
• The gateway/bridge functionalities enable the
integration of WMNs with existing wireless
networks(cellular, sensor net, Wi-Fi, WiMAX).
• Mesh Clients
• Conventional nodes (e.g., desktops, laptops,
PDAs, Pocket PCs, phones, etc.) equipped with
wireless network interface cards (NICs), and can
connect directly to wireless mesh routers.
• Customers without wireless NICs can access WMNs
by connecting to wireless mesh routers through,
e.g., Ethernet.


17. Diagram of Mesh Technology

18. Advantages
• requires only one node in the network to be physically wired for internet connection;
• provides collaborative, redundant backup technology, which ensures data security in the event of disk failure;
• is able to be configured dynamically for speed;
• uses less power;
• offers increased reliability, as each node is connected to several other nodes and, if one drops out of the network, its
neighbors simply find another route;
• uses the same set of standards as most Wi-Fi networks -- 802.11a, b and g;
• is scalable, as it is typically easy to add nodes to the network; and
• can effectively provide coverage to home Wi-fi mesh networks without reducing bandwidth, unlike Wi-Fi range extenders.

19. Disadvantages
• Networks with low processing capabilities may have more latency, as
data often must hop through several different nodes.
• The lack of a central server can make mesh systems more complicated
to monitor, control and troubleshoot.
• The lack of centralization can make routing and resource management
processes more complex than with other types of wireless networks.
• Initial network setup can be complex, as ideal node placement across
different points in the area will likely involve some trial and error.
• For homes, node devices can be less cost-effective than traditional
router/modem Wi-Fi networks.

20. Conclusion
 It can be concluded that Multi-Radio, Multi-Channel wireless mesh
topology is best over all other topologies which helps us to improve
the network performance by increasing network throughput and
decreasing the delay in the network.

21. REFERENCES

[1] Blackmore, S.(1994). Precision Farming: An Introduction. Outlook on Agriculture 23(4) 4, 275-280.
 [2] Ning Wang, Naiqian Zhang, Maohua Wang, “Wireless sensors in agriculture and food industry—Recent development and future perspective”, published in Computers
and Electronics in Agriculture 50 (2006) 1–14.
 [3] Akyildiz, I.F., Xudong Wang: A Survey on Wireless Mesh Networks, IEEE Communications Magazine (September 2005)
 [4] Azo Nanotechnology Article: “Precision Agriculture - Nanotech Methods Used, Such as ‘Smart Dust’, Smart Fields’ and Nano sensors:”
http://www.azonano.com/details.asp.ArticleID=1318
 [5] “SoilNet - A Zigbee based soil moisture sensor network” Project Group, Institute Of Chemistry And Dynamics Of The Geosphere (ICG), Agrosphere Institute, ICG 4,
Forschungszentrum Jülich GmbH, 52425 Jülich, http://www.fz-juelich.de/icg/icg-4/index.php.index=739
 [6] IEEE Std. 802.15.4-2003, Wireless Medium Access Control (MAC) and Physical Layer (PHY) Specifications for Low Rate Wireless Personal Area Networks (2003)
 [7] CC2420: http://focus.ti.com/docs/prod/folders/print/cc2420. html
 [8] Kwang Koog Lee, Seong Hoon Kim, Yong Soon Choi, Hong Seong Park: A Mesh Routing Protocol using Cluster Label in the ZigBee Network, IEEE International
Conference on Mobile Adhoc and Sensor Systems (October 2006)
 [9] Ran Peng, Sun Mao-heng, Zou You-min, ZigBee Routing Selection Strategy Based on Data Services and Energybalanced ZigBee Routing, IEEE Asia-Pacific conference
on Services Computing (December 2006)
 [10] Ho-In Jeon, Yeonsoo Kim: Efficient, Real-Time Short Address Allocations for USN Devices Using LAA (Last Address Assigned) Algorithm, 9th International Conference
on Advanced Communication Theory (February 2007)