Network Protocols

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Running Head: Network Design

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Network Design

University Affiliation

Course

Date

Professor

Wide Area Network Design

An enterprise network is a diverse and large network connecting most major points in a company, business or other organization. An enterprise differs from a WAN in that it is privately owned and maintained. There are a variety of WAN technologies to meet the different needs of businesses and many ways to scale the network. An enterprise must subscribe to a WAN service provider to use WAN carrier network services (Paquet, 2013).

In designing of the WAN portion of the network, the first step is to understand the specific network characteristics of the various locations from a Wide Area Network point of view and to then analyze and decide how to implement WAN connectivity at each location. The proposed WAN has specified both possible leased line as well as point to point radio connectivity between sites (Zhang, 2005). It is recommended that the wide area network connection between remote offices should be a point to point radio link. The Plant facility in one location has the capability of using satellite communications or other leased lines for this deployment. Also, for high availability it is recommended that all locations also have site to site redundant links over the Internet through the use of (virtual private network) VPN connectivity. VPN technology will enable organization to create private networks over the public Internet infrastructure that will maintain security and confidentiality. We will use VPNs to provide a virtual WAN infrastructure that connects branch offices to all or portions of their corporate network. 

Different applications require varying amounts of network bandwidth the bandwidth required between these sites is dependent upon several factors that include amount of traffic (which varies depending upon the number of users connected to the network), number of hosts, number of network users, protocol being used, potential applications deployed on the network and the network design. For offices with lower bandwidth requirements the most recommended Frame Relay connection should provide no less than 768Kbps while locations with a larger bandwidth requirement will need point to point T1 connections (around 1.54Mbps). To determine which type of connection is appropriate at each location, a list of the approximate number of users and hosts at each site along with the applications they use will be we put in consideration when coming up with the equation for properly determining bandwidth requirements for the network. The required bandwidth in this case will be measured by first determining the amount of space available to transfer data. So for the T1 connections we need to divide 1.54Mbps by 8 to get the number of bytes per second available on the WAN connection. Therefore, a T1 connection will support 192 Mbps. Next, we will determine the amount of bandwidth needed for each application, which in some cases is available from the vendor and capture a sample of the network traffic generated by category of user at specific times of the day and week. Then we will compare the average the amount of data in Mega Bytes captured per second multiplied by the number of hosts/users that will use the link and compare it to the amount of bandwidth available (such as the 192 Mbps supported by T1 connections). Bandwidth for wireless links such as satellite can be calculated using the same formula however their total available bandwidth changes considerably throughout the day so an additional 35% bandwidth may be taken into consideration to ensure the measurements are realistic (Ramasamy, 2007).

Altogether there are five locations for this organization that must be connected via Wide Area Network links, within these five locations multiple user and host groups must be identified and defined to create a virtual network topology. These user and host groups will then be separated by Virtual LAN’s (VLAN’s). They are managed by the network devices across the WAN in order to ensure there is logical separation of devices according to the network requirements. Then, based upon the bandwidth calculations, (quality of service) QoS can be implemented for each WAN link using inter VLAN assignments to assign bandwidth to each group and ACLs to control each groups flow of traffic. An ACL is a sequential list of permit or deny statements that apply to addresses or upper-layer protocols. Therefore, through the use of combined VLANs, ACLs and QoS, the wide area networks between locations can be optimized to perform better by eliminating slow connections due to congestions. In addition, WAN configuration can be adjusted on a schedule that will allow higher priority to traffic within certain periods of time.

A proper firewall device to protect networks from unauthorized use it’s ideal. A VLAN allows a network administrator to create groups of logically networked devices that act as if they are on their own independent network, even if they share a common infrastructure with other VLANs. The benefits of VLAN are providing security to the network, storm mitigation, broadcast, cost reduction, and improved IT staff efficiency. When VLANs are implemented on a switch, the transmission of multicast, Unicast, and broadcast traffic from a host on a particular VLAN are constrained to the devices that are on the VLAN. The recommended firewall for each location with a local point of presence would be the Cisco ASA series7 200 modern series that supports VPN and VLAN technologies and also high throughput services.

 

The proposed routing devices for all distribution locations would be the Cisco 2850 series router which would include an internal T1 WAN Interface Card for connectivity directly to the main office. The 2850 router can also be used as a firewall if the VPN redundancy option is put in consideration. At each location where required, there should be at least one layer 3 capable (VLAN capable) switch that can provide at least 1Gbps link speeds. The proposed VLAN capable switch solution would be the catalyst 2960-X Cisco switch which provides the ability to separate different host groups and users as required at each location for bandwidth conservation and added security measures. Broadcast dependent protocols that are necessary to centralize network administration, such as DHCP can still be managed and maintained centrally using DHCP Helper configurations on the router at each location. It as a feature that forwards DHCP broadcasts as unicast traffic to next network hop or host which ensures that the DHCP protocol will work properly across WAN connections without consuming a lot of bandwidth (Comer, 2004).

Implementing Teleworker services in the network it’s also very important. Teleworkers typically use diverse applications (for example, e-mail, web-based applications, real-time collaboration, videoconferencing and video) which require a high-bandwidth connection. The choice of access network technology and the need to ensure suitable bandwidth are the first considerations to address when connecting teleworkers.

The switches can be the same in all locations by again using the Cisco 2960-X, which Provides PoE(power over ethernet) support with up to 740 W of power ,interface connections to hosts and other network devices (Cisco,) and serve as a core switch for the network. However, for the HQ location specifically, the Cisco 3750 series switch would be the preferred choice as it provides a high level of extensibility, including 128 Gbps speeds between switches, which will avoid the potential bottlenecks that can occur with trunk links, and the configuration issues and limitations of aggregated uplinks. The HQ building router must be highly capable, with the specific ability to support VPN connectivity from multiple locations, provide firewall services for the company, and also support multiple T1 connections. If all sites opt to run Cisco routers, then the proposed routing protocol would be Cisco's proprietary protocol EIGRP due to it's low bandwidth utilization, low convergence times and provision for prioritizing network paths. However, in the event that legacy networks or equipment from different vendors are proposed for future expansion and maintenance, the routing protocol of choice to serve as a fallback would then be the Open Shortest Path First standard protocol rather than EIGRP.

 The Cisco devices specified above can be easily leveraged for both voice only networks as well as data and data combined networks. Other options, which are available when purchasing Cisco switches, include PoE functionality that provides power to IP phones and other devices through the same Ethernet cable that provides data and without any additional equipment. In addition, by using a standard vendor such as Cisco for all sites, the administrative overhead and total cost of ownership for the network is greatly reduced as it generally ensures proper integration and interconnectivity between devices (Medhi, 2007).

Cabling Specifications

The delivery of frames across the local media requires the following Physical layer elements:

1. The physical media and associated connectors

2. A representation of bits on the media

3. Encoding of data and control information

This organization (company) is comprised of several, separate departments, they are necessary for conducting a company in a more efficient and reliable manner. Communication between these departments is required to ensure day to day operations run accurately. The company will be concerned with security when designing a strong and reliable network security program. In the event of program failure, the networking program must provide network access to the majority of its employees through segment and sufficient cabling, thus eliminating the possibility of a decrease of productivity. This network will offer the ability to share network devices such as scanners, copiers, printers providing internal and external data, for those in need of access. The network will have a central storage unit for file sharing, which will be used by various departments. The system capabilities will include an authentication for verification process for all authorized employees and expansion capabilities for additional network devices when the need arises. The star topology uses a wide range of different kinds of cabling types. A few of the types of cable that can be utilized by a star topology network are; fiber optic cable, twisted pair cable and coaxial cable (Comer, 2004).

UTP cabling are terminated with RJ-45 connectors, is a common copper medium for interconnecting network devices. The twisted pair cables can be found in many types, depending on performance. The most popularly used to connect to personal network computers is the Category 6(Cat-6). The company's network design will use twisted pair cables to connect devices to the switches using 10base-T (10 Mbps, twisted-pair (two pairs, Cat-5 or higher) cable. 10base-T cable is used because of its maximum length of 100 meters.

The fiber optic cable can be used to interconnect switches. Prior to the installation of the network cabling, Network Cabling Specification Checklist will be created. Information from the checklist provides proper cable and connectors to be installed at different floors, Fiber optic cables are used due to transmission of high-speed voice and data traffic in enterprise and service provider network. The transmission rate is higher since it uses light to transmit information.

After network installation, documentation is important since it entails certification information that show all installed cables operate properly and that a network test device was used.

Network Cabling Specification Checklist

· Category 6a Cable

· RJ45 UTP socket

· Category 5epatch cable

· RJ45 UTP plugs

· Category 6 cable with maximum lengths of 100 Meters.

· 10Base-T cable

· Fiber optic cable.

· Single-mode lucent connector(LC)

Cable type	Standard	Application
Ethernet Straight through	Both end T568Aor both endT568B	Connecting a network host to a network device such as a switch or hub
Ethernet Crossover	One end T568A other end T568B	Connecting two network hosts. Connecting two network intermediary devices(switch to switch, or router to router)
Rollover	Cisco proprietary	Connected a workstation serial port to a router console port, using an adapter

LAN Topology

When building a LAN that satisfies the needs of a given company, the plan is more likely to be successful if a hierarchical design model is used. Since it’s easier to expand and manage and problems are solved more efficiently. LAN technologies provide both speed and cost-effective for the transmission of data and voice in organizations over relatively medium geographic areas. However, there are other business needs that require communication among remote sites, including the following:

· People in the regional or branch offices of an organization need to be able to communicate and share data with the central site.

· Organizations often want to share information with other organizations across large distances. For example, software manufacturers routinely communicate product and promotion information to distributors that sell their products to end users.

· Employees who travel on company business frequently need to access information that resides on their corporate networks.

The optimal choice, all things considered, would be to implement a star topology network in each or the department offices. Using a switch as a central device for linking the computers and other devices on the LAN, this networking set up will offer the most manageable network. Different devices are connected to the network with corresponding networking cables. Expansion is accomplished easily dependent upon how many ports on the switch are available for use. When selecting a switch for the access, core layers or distribution consider the ability of the switch to support the port density, forwarding rates, and bandwidth aggregation requirements of your network. High port densities allow for better use of space and power when both are in limited supply. If you have two switches that each contain 24 ports, you would be able to support up to 46 devices, because you lose at least one port per switch to connect each switch to the rest of the network. In addition, two power outlets are required. On the other hand, if you have a single 48-port switch, 47 devices can be supported, with only one port used to connect the switch to the rest of the network, and only one power outlet needed to accommodate the single switch. The switch ports are configured with the right ip address to ensure effective switching and routing (Paquet, 2013).

If additional ports are needed on the switches, two switches can be linked together to provide more connectivity. Providing that space is available for this type of expansion and one needs to add more computers, this can be accomplished by easily connecting the computers to the available port on the hub. An advantage of a star topology means not having to shut down the network, causing interference with other devices while the network is up and running.

Devices can also be connected using wireless media. This will help to reduce the network traffic. By keeping the network design as simple as possible, this will allow the company's maintenance of the network to be done easily and effectively. With all departments within the organization connected using the star topology, all will be terminated at individual network devices housed in the Intermediate Distribution Frame (IDF). The switch that connects to the network's router is also held in this closet. Aside from ease of access, the close proximity of the departments makes this the best layout allowing the system to be expanded (Zhang, 2005).

IP ADDRESSING

172.17. y.x/24

As we have a full class C network (a Class B address with a class C mask). The first 3 octets represent the network portion while the last octet represent the host portion of the IP address. In order to subnet a network extends the natural mask using some of the bits from the host potion of the address to create a sub network. In my network design, each floor in a building will be in a separate sub-network. Thus in each of the five buildings in different location, we will have 3 subnets. The design is as follows:

Creating subnets

IP=172.17.1.0/24

Written in binary = 10101100.00010001.00000001.00000000

In this IP address we have 24 network bits and 8 host bits

10101100. 00010001. 00000001.00000000

Network bits host bits

Borrowed bits

11111111.11111111.11111111.11000000

Network bits host bits

With 2 borrowed bits from the host portion it’s possible to create 4 subnets which satisfy my design requirements of three subnets (each floor to be in its own subnet).

Using the formula 2n where n number of borrowed bits

22=4 subnets

To get the number of addresses in each subnet we use the formula 2n-2 where n= number of host bits

26-2= 62 addresses per subnet

	Subnet	Network address	Host range	Broadcast address	Subnet mask
Location 1 network	Floor 1	172.17.1.0	172.17.1.1 To 172.17.1.62	172.17.1.63	255.255.255.192
	Floor 2	172.17.1.64	172.17.1.65 To 172.17.1.126	172.17.1.127	255.255.255.192
	Floor 3	172.17.1.128	172.17.1.129 To172.17.1.190	172.17.1.191	255.255.255.192
	Reserved	172.17.1.192	172.17.1.193To 172.17.1.254	172.17.1.255	255.255.255.192
Location 2 network	Floor 1	172.17.2.0	172.17.2.1 To 172.17.2.62	172.17.2.63	255.255.255.192
	Floor 2	172.17.2.64	172.17.2.65To 172.17.2.126	172.17.2.127	255.255.255.192
	Floor 3	172.17.2.128	172.17.2.129 To172.17.2.190	172.17.2.191	255.255.255.192
	Reserved	172.17.2.192	172.17.2.193 To172.17.2.254	172.17.2.255	255.255.255.192
Location3 network	Floor 1	172.17.3.0	172.17.3.1 To 172.17.3.62	172.17.3.63	255.255.255.192
	Floor 2	172.17.3.64	172.17.3.65 To 172.17.3.126	172.17.3.127	255.255.255.192
	Floor 3	172.17.3.128	172.17.3.129 To172.17.3.190	172.17.3.191	255.255.255.192
	Reserved	172.17.3.192	172.17.3.193To 172.17.3.254	172.17.3.255	255.255.255.192
Location4 network	Floor 1	172.17.4.0	172.17.4.1 To 172.17.1.62	172.17.4.63	255.255.255.192
	Floor 2	172.17.4.64	172.17.4.65 To 172.17.4.126	172.17.4.127	255.255.255.192
	Floor 3	172.17.4.128	172.17.4.129 To172.17.4.190	172.17.4.191	255.255.255.192
	Reserved	172.17.4.192	172.17.4.193 To172.17.4.254	172.17.4.255	255.255.255.192
Location 5 network	Floor 1	172.17.5.0	172.17.4.1 To 172.17.4.62	172.17.5.63	255.255.255.192
	Floor 2	172.17.5.64	172.17.4.65 To 172.17.4.126	172.17.5.127	255.255.255.192
	Reserved	172.17.5.128	172.17.4.129 To172.17.4.190	172.17.5.191	255.255.255.192
T1 Link networks	1	96.68.111.1
	2	96.68.111.2
	3	96.68.111.3
	4	96.68.111.4
	5	96.68.111.5

References

Comer, D. (2004). Computer networks and internets: With Internet applications (4th ed.). Upper Saddle River, N.J.: Pearson/Prentice Hall.

Medhi, D., & Ramasamy, K. (2007). Network routing algorithms, protocols, and architectures. Amsterdam: Elsevier/Morgan Kaufmann.

Paquet, C. (2013). Implementing Cisco IOS network security: (IINS 640-554) foundation learning guide (Second ed.). Indianapolis, Indiana, USA: Cisco Press.

Zhang, L. (2005). Network design. New York, NY: Springer.