Security Specialists Careers

Network security specialists also manage the compromise of sensitive information concerning cyber attacks including viruses, worms, and other destructive software devices that are able to get through firewalls. Anti-virus software continues to get more and more sophisticated as computer predators get more creative and more destructive.

A network security specialist often conducts other kinds of security measures. New laws related to the U.S. Department of Homeland Security require U.S. businesses to monitor the electronic communications of their employees including emails, instant messaging and phone calls. Monitoring software exists that flags words such as "bomb," "kill" and "drugs" to allow individuals in computer careers such as this to investigate the context of employees' communications that include such words. You may be required to collect data related to security-related incidents and investigations.

The job functions of a network security specialist are often broad to fulfill the unique needs of a particular office. Although specialization improves your marketability, you will do well to take additional coursework and gain a broad range of computer skills so that you are more adaptable to industry changes. Crossover also exists in many computer-related jobs. The additional training is helpful, especially if you perform additional functions outside the industry standard. It is also helpful in your interaction with your co-workers in other computer careers. Your knowledge of business functions is also helpful in this profession.

Network Security Specialist

A network security specialist, or a computer security specialist, is a kind of computer administrator that specializes in protecting a company's data and other information. Network security specialists build firewalls, install anti-virus software on servers and computers within a network, and monitor networks for breaches in security. Individuals in computer careers such as this that specialize in one kind of systems maintenance usually work for large companies or organizations with particularly sensitive data, such as investment firms, insurance companies and government agencies.

The network security field is quickly growing right now as more businesses and individuals are storing sensitive data electronically. In addition to the technical roles of this position, a network security specialist often provides training to general staff regarding security issues, and he may develop related company policies such as security matters related to accessing company information using a smart phone, a mobile laptop, or home computer and transmitting information using a thumb drive or an external online data storage service. Often a network security specialist will help facilitate authorized mobile access of company information so that proper security measures can be in place.

Breaches of confidential information stored by a business or organization can be disastrous. If the breach involves unauthorized access to personal information, it can lead to legal problems in terms of liabilities. And if the blueprint of a new product a business plans to launch fall into the wrong hands, it can jeopardize a company's competitive advantage. As a result, network security is drawing more and more attention by executive management.

Laws govern industries regarding the way they store and access personal information of clients, patients or customers. Personal information includes Social Security numbers, personal financial information, medical information and personnel information. It may be as simple as names, addresses and phone numbers, or it may be psychographic market research data collected that customers are not even aware exists. Individuals in computer careers such as this are often required to pass extensive background checks. Their position also requires good judgment and the utmost discretion.

NETWORK PROTOCOLS

To avoid chaos in computer communications, rules must be established for the exchange of data from one site to another. These rules are known as line protocol. Communications software packages control the speed and mode of communications between computer systems.

Many different standard network protocols exist to perform addressing, routing, and packetizing. All provide formal definitions for how addressing and routing is to be executed, and specify packet structures to transfer this information between computers.OSI, TCP/IP, IPX/SPX, and X.25 are commonly used routing protocols.

Open Systems Interconnection (OSI):

A major problem of early networked computer systems was that a lack of consistency existed among the protocols of different types of computers. Consequently, various efforts have resulted in the establishment of standards for data transmission protocols. For example, the International Standards Organization (ISO) developed a set of standard protocols called the Open Systems Interconnection (OSI). The OSI model separates each network's functions into seven layers of protocols, or communication rules. This model identifies functions that should be offered by any network system.It is important to note that the physical layer, data link layer, and network layer appear in the user and host computers as well as units such as the front-end processor and the cluster control unit. The remaining layers appear only in the user and host computers.

TCP/IP:
TCP/IP (Transmission Control Protocol/Internet Protocol) is a set of communications protocols developed for internetworking dissimilar systems. This is supported by many hardware vendors from microcomputers to mainframes. It is used by most universities, federal governments, and many corporations. TCP/IP has two parts. TCP protocol controls data transfer that is the function of the transport layer in the OSI model. IP protocol provides the routing and addressing mechanism that are the roles of the network layer in the OSI model.
The TCP/IP may be the oldest networking standard, and is also the most popular network protocol, used by almost 50 percent of all installed backbone, MAN (metropolitan area network), and WAN (wide area networks). TCP/IP is widely compatible with many other protocols. Although TCP/IP supports many protocols, it is usually associated with Ethernet. TCP/IP is also the network protocol used on the Internet.

IPX/SPX:
IPX/SPX (lnternetwork Packet Exchange/Sequenced Packet Exchange) is a Novell NetWare communications protocol used to route messages from one end to another. It is the major network protocol used by Novell NetWare, and about 40 percent of all installed LAN (local area networks) use this protocol.
IPX/SPX has two parts, and is similar to TCP/IP. SPX controls the transport layer in the OSI model. It guarantees that an entire message arrives intact. IPX manages the role of the network layer in the OSI model and is used as delivery mechanism for SPX. IPX/SPX can be linked with many other protocols.

X.25:
X.25 is a CCITT standard developed by ITU- TSS for WAN (wide area networks). It defines the interface between an end user computer and packet switching network. This is an international standard used for many worldwide corporations. It also has two parts. Packet layer protocol (PLP) is the routing protocol that manages the network layer and X.3 controls the transport layer.

Network Architecture

A Network is a conceptual framework that describes how data and network information are communicated from an application on one computer through network media to an application on other computers in terms of different layers. Network architecture is also known as Reference model. There mainly two classifications of Reference models and are Open and closed.

Open model is one which is open for everyone and no secrecy is there. In a closed model, also known as proprietary system the architecture is kept secret from users. OSI model is an open model while IBM's SNA 7 layer model is a closed system. Here Let's discuss two main reference models OSI model and TCP/IP model.

TCP/IP Model (Internet Architecture):

• TCP/IP ( Transmission Control Protocol/Internet Protocol) defines a large collection of protocols that allow computers to communicate.It has a 4 layer architecture. 
• TCP/ IP defines each of these protocols inside document called Requests For Comments (RFCs). 
• By implementing the required protocols in TCP/IP RFCs, a computer can be relatively confident that it can communicate with other computers that also implement TCP/IP.

Routing Algorithms

Non-Hierarchical Routing:

In this type of routing, interconnected networks are viewed as a single network, where bridges, routers and gateways are just additional nodes.Every node keeps information about every other node in the network
In case of adaptive routing, the routing calculations are done and updated for all the nodes.The above two are also the disadvantages of non-hierarchical routing, since the table sizes and the routing calculations become too large as the networks get bigger. So this type of routing is feasible only for small networks.

Hierarchical Routing:

This is essentially a 'Divide and Conquer' strategy. The network is divided into different regions and a router for a particular region knows only about its own domain and other routers. Thus, the network is viewed at two levels:

The Sub-network level, where each node in a region has information about its peers in the same region and about the region's interface with other regions. Different regions may have different 'local' routing algorithms. Each local algorithm handles the traffic between nodes of the same region and also directs the outgoing packets to the appropriate interface.The Network Level, where each region is considered as a single node connected to its interface nodes. The routing algorithms at this level handle the routing of packets between two interface nodes, and is isolated from intra-regional transfer.Networks can be organized in hierarchies of many levels; e.g. local networks of a city at one level, the cities of a country at a level above it, and finally the network of all nations.

In Hierarchical routing, the interfaces need to store information about:

• All nodes in its region which are at one level below it.
• Its peer interfaces.
• At least one interface at a level above it, for outgoing packages.

Advantages of Hierarchical Routing :

• Smaller sizes of routing tables.
• Substantially lesser calculations and updates of routing tables.

Disadvantage :

Once the hierarchy is imposed on the network, it is followed and possibility of direct paths is ignored. This may lead to sub optimal routing.

Flow Models

A computer network is comprised of nodes corresponding to network elements such as workstations,routers and switches and links that connect those elements. A network now contains all the traffic originating at a node and destined for some other node in the network. Each how can in principle traverse a set of paths connecting its origin and destination, which is determined by the routing policy.

In computer networks, the low traffic is carried on packets, whose payload is expressed in bytes, while on road networks, the traffic is carried on vehicles. The volume of traffic measured on a link may refer to either the number of packets and/or the number of bytes in computer networks, and such data for a particular time interval -typically of the order of a couple of minutes- are available through queries using the Simple Network Management Protocol (SNMP) protocol.

 The volume of traffic on a 1link is the sum of volumes of all rows traversing that link. This produces highly aggregate data and the question of interest is to estimate various statistics of the underlying network.

Dynamic Network Mapping

For enterprise networks, static maps such as Visio diagrams take a significant amount of effort to create and they can become obsolete quickly. Dynamic mapping is the next generation mapping automation technology, featuring:

• Data-driven map automation – maps with rich details can be created instantly
• On-demand map creation - each map is customized for the task at hand
• Automatically updated – when the live network changes, maps can be updated accordingly

Automated Network Documentation:

• To automate network documentation, NetBrain leverages a state-of-the-art discovery engine that discovers both network topology and the network design underneath. Any network change will be automatically captured by recurring discovery.
• Network documentation is available in the following formats:
• Diagrams in Visio format
• Design documents in Word format
• Inventory reports in Excel format

Map-Driven Network Troubleshooting:

Instead of typing commands into the CLI to figure out what’s happening, you can troubleshoot complex network problems in a map-driven environment from beginning to end. With this unique map-driven troubleshooting tool, you can:

• Map a problem area instantly through on-demand mapping technology.
• Visualize performance hotspots and up/down status directly through a color-coded dynamic map.
• Analyze what’s changed in topology, routing, configuration and traffic flow.
• Run Automation Procedures to immediately find errors and discrepancies.