KINGSTON UNIVERSITYNetwork Design and Management Coursework CIM238 Amarpreet Singh Saini K1051678 6/17/2011 A company in Greece named Gamling Printing CO. asked out team to design a network based on specifications and requirements provided by them. Based on the requirements of the client our team designed a network which is reliable, secure, manageable and robust. 1. Executive Summary This report is done on behalf of Gamling Printing Co. for the purposes of designing a network based on the requirements and specifications provided by the organisation. The information contained in this document is confidential and sensitive and should be handled with care. Based on the requirements specified by the organisation, we have designed a network which fulfils and serves all the requirements outlined and detailed, which is secure, managed, reliable, adaptable and cost effective. It not only meets the current demands but also provides the capacity for future growth. Furthermore standards and recommendations of feasible technology are also outlined in this document. The proposed network design offers a number of advantages over the currently utilized network design. Ensures that the network infrastructure is well positioned so as to avoid physical disasters. Network infrastructure that is more reliable, flexible and cost-effective. A network that can meet the current demands put forth by the organisation and has the capacity for future growth. Provides consistent improvements in services. Ensures a level of robustness required by the organisation for the efficient functioning of its business. The proposed network can be implemented with minimal disruption and less downtime. Below is a figure illustrating the process of migrating to the new network design. Fig. 1 The new network has the following key features in terms of technical solutions implemented. The terminals are wired into a 1Gbps LAN due to the high bandwidth requirement of the internal network. The hardware is very cheap and affordable and a single server rack is all that is used to setup the network. This is very beneficial when backups are taken into consideration. The design is maintenance free and requires very little technical expertise to operate and even diagnose due to its simplistic nature. It uses a single Application/Domain controller and a Network Attached Storage that is critical to the functioning of the network. The existing network can’t handle the quick deployment of new services required by the organisation.2. Lack of fault tolerance. The services are to be discussed in detail in design section of this document but for the purposes of the requirement specification we list them here. There are many different technologies used which are very difficult to manage. Requirement Analysis Business Requirements The network upgrade as specified by Gamling Printers Co is required to: Update the outdated and aging infrastructure Minimize the cost of the network infrastructure Support future business expansion Increase productivity Offer flexibility and scalability in terms of bandwidth required for various kinds of services and differing business traffic types Add a level of security to the business-specific and sensitive information transmitted. Due to adoption of such legacy options much of the time is wasted on resolving solutions that can be avoided in the first place by having a standard conforming model. Print. These are HTTP for web data. Database Query and Fetching and FTP to access the Network Attached Storage (NAS). Offer alternative and multiple means of access such as wireless LAN Disaster recovery and redundancy and appropriate mechanisms to mitigate consequences. It can be noted that the internal LAN needs a high speed channel whereas the organisation can opt to go for a less fast line for connecting to the internet as their HTTP usage is only medium load. Connectivity options like as coaxial cable is a big constraint. Due to the nature of the business as a printing facility they run photo editing and design software on all the machines. Be ready to embrace new technologies in the future as required by the business. Existing network Infrastructure The various deficiencies and risks associated with the current network employed by the organisation are: The current network is highly rigid to maintain because it does not conform to standards. Guarantee minimal delay for applications that are critical to the organisation A highly available network that can help minimizing planned and unplanned downtime. Absence of a strong security solution is a big threat to the organisation’s assets. The organisation runs many services on the workstations. . The cost to maintain the current is excessive and drains a lot of capital than it should be. There is no security policy implemented at the organisation premises. Design and Architecture To construct the new design for the network we used many techniques and approaches. Also there is only one link for connecting to the internet. Redundancy is also available in case of an outage of failure of network components. We now discuss them briefly. This allows for better network performance as the link used within the internal network is a 1 Gbps line. Right now the service is used for internal wireless printing services but it can be configured to provide internet access to customers or internal employees. and environmental aspects as such. These included an interactive backup solution.the number and speed of access points. availability usually depends on the network. Discussion Discussions were held so that various constraints. management is substantially easier.3. Since we use single vendor products namely Cisco routers. business requirements and future directions could be taken into consideration. analysed and documented. Various aspects of the network were studied and investigated. - - - . Hence adding redundancy is a good investment and resources should be allocated for it. Although MTTF is a factor. switches and HP servers and terminals. Some of those are. The proposed network design and Considerations The terminals will in a centrally switched infrastructure which will allow for easier management. which as told by the organisation management can be handled by them manually. details of applications and services used. There were some aspects of the network that were however excluded and not taken into consideration while designing the network. Requirements were documented and used as the building foundation for the design Traffic Analysis Data flow and volume were gathered for recognising various bottlenecks that could be affecting the existing setup and also prioritizing the areas that were more critical Migration Plan Development of a migration plan occurred as well by which the proposed design could be implemented smoothly so that the networks remains highly available during the transition. Studying the existing network The existing network design was studied. High availability depends on both the services and the whole network. Both the servers and the terminals will have a better access speed in the network than the existing network setup. Wireless access is also possible. transmission channel information. a Cisco router.Fig. The firewall again is a Cisco product with the terminals along with the printers and scanners being HP products again. Fig. switch and wireless AP. 3 List and number of equipment employed . 2 Network design The network design consists of a HP server that is application and domain controller. The list of equipment is listed in the figure below. - - In the figure below we show the actual floor plan with the server rack used on the organisation’s premises. We now outline some of our design choices. the wireless printers and the terminals. 4 Floor plan along with server rack diagram . the Network Attached Storage. The terminals are connected to the switch using UTP Cat6 cable whereas the printers and plotters are wirelessly connected via the means of and wireless Access Point. The router is connected to a Cisco hardware firewall solution. In such a case employees can use the printers near to them due to their wireless nature. Fig. A central storage offers a lot of benefit than individual storage devices on the terminals. This 1 Gbps switch is connected to the Domain controller/Application server.We have an ATM e3 line connected to an ADSL modem which is further connected to a router. The printers are wireless as due to intensive use their fail often. The Network attached storage is a highly beneficial investment as it can be easily backed up manually as per the organisation’s requirements. which is further connected to a switch. This saves a lot of time and effort. The 1 Gbps switch is only for the internal network as simultaneous requests are made to the network attached storage. Plus the huge file sizes make the internal network bandwidth intensive. Simulation . 33378. There are 2 wireless plotters on the floor.2531822919846 Gigabyte per month 5. Each workstation has a wireless printer next 2 it. The UTP Cat6 cable runs along the length of the premises. The mean time to repair as given by the organisation is 3 minutes. Availability= MTBF/ (MTBF+MTTR) MTTR=3 minutes*52 weeks=106 Agreed service uptime = 24*60*365=525600 MTBF= (Agreed service uptime. In the actual scenario we have more terminals than those.60107421875 Megabyte per day or 991. Traffic in megabytes per day = EmployeePerDay * RequestPerEmployee * PageSize / 1048576 The 10 employees each handle around 70 jobs every day generating a data of about 50000000 bytes on an average request.For the sake of demonstration we have only employed 4 sets of terminals and devices.9997983257 The overall availability percentage is 99% We calculate the traffic generated over the internal network in the following manner. Specification The availability of the network link is explained below.MTTR) =525600-106=525494 Availability= MTBF/ (MTBF+MTTR) = (525494/525600) =0. 4. Using MTTR as 3 minutes we derive availability as follows. . to a router to a firewall.For the purposes of the simulation which we performed in OPNET we used the following network design. There is an ATM e3 line connected to an ADSL Modem. The switch is connected to a single server that serves the dual purpose of NAS and Domain controller. The firewall is connected to a 16 port 1Gbps switch. We have excluded the wireless products out of the simulation. There are 10 workstation connected to the switch. The simulation ran for 1 day during which no traffic was dropped as shown in the simulation result. . As said before our model dropped no traffic.The above figure shows detailed statistics for the network health. . . As we can see that this is very low.000035 which is a very good value. only peaking less than .The above figure shows the delay in seconds the Ethernet. .The above simulation result shows the response time for the DB Query service along with traffic sent and received in packets per second and bytes per second. .The above screenshot shows the TCP delay in seconds for a whole day which again is very low. .The above figure shows the simulation results for TCP Segment delay. Group Coursework Presentation Athanasios Politis Amarpreet S Saini Alkiviadis Tsitsigkos . Client Background Small size business Copy Centre Business 5 employees Plain Home Network Utilisation . Requirements Fast & Reliable Network Secure Network Storage Wireless connectivity Improve Network Security to avoid data leakage on Internet . Proposed Hardware . Floor Plan . Design Choices Wired Terminals. Capable of expanding in near future . Wireless Printers Cheap & affordable hardware Maintenance FREE design. Conclusion More secure & robust than it used to be Had a Home Network Implementation and now has a Small Business Network Implementation Business is more agile with Wireless connectivity now Future Expansion Capability . Priority. Fig. The techniques are based on Markovian model and priority model. Due to GPRS users can benefit from faster data rates than before with much short wait times. Abstract Due to the need of many quality-of-service requirements of voice and data in GSM/GPRS networks. Sharing. a mobile station (MS) communicates with a base station subsystem (BSS) via the wireless communication link. Channel allocation. [1] Here in the figure below we can see an implementation of GPRS over a GSM network. channel allocation techniques are very vital as far as system performance gains are concerned.Wireless Link Dimensioning 1. A study on the paper by Marques and Bonatti where they present and compare of two techniques for wireless link dimensioning of telecommunications networks is discussed in this paper. Introduction The integration of GPRS and GSM is a significant change that has hushed in a new era in the wireless networking and communication field. The base station is connected to the mobile switching centre (MSC) . A brief introduction of GSM/GPRS is also presented along with a look at channel allocation schemes by other researchers. Markov. 2. Due to the vast and crucial need of many quality-of-service requirements of voice and data in a GSM/GPRS network. 1 GPRS over GSM [2] In a GSM network. channel allocation techniques are highly important as one can achieve a significant increase in system performance. GPRS enables easier access to packet switched networks in a wireless communication medium. Key Terms – Wireless link dimensioning. Both these services are allocated equal slot numbers. Agrawal in their paper “Performance analysis of preemptive handoff scheme for integrated wireless mobile networks” discuss various channel allocation schemes for transmission of multimedia content in integrated networks such as GPRS/GSM. [5] analyzed and compared performances of many channel allocation schemes and also put forth a dynamic channel allocation scheme based on queuing. The Base station and the Mobile Station communicate via the air interface specified for GSM/GPRS networks. Wang. [2][3] In the GPRS/GSM architecture.. Tonguz in their paper “Dynamic priority queuing of handoff requests in PCS” discussed the dynamic priority queuing for voice over GSM in Personal Communication System. The channel allocation schemes used in such networks do not distinguish between differing bandwidth requirements for voice and data traffic. Efficient usage of available channels is therefore a high priority task in the area of resource management. Channel Allocation in GPRS/GSM Channel Allocation here is quite elastic as many channels can be allocated to a single user if the need arises or one channel can be shared by several. In Integrated networks for voice and data such as GSM circuit switching is employed which hugely beneficial in voice transmission is very inefficient for data transmission due to the nature of data which can have erratic and burst nature. Xhafa and O. and HLR are structured differently.g. the home location register is further tuned to accommodate GPRS user data such as credentials. MS. A. P. and packet dedicated control channels (PDCCHs) used to convey the GPRS control signalling for a dedicated MS. The SGSN makes sure that the mobile stations receive the packets intended for them. Every communication medium has a limited number of channels. Zeng. Q. Packet data channel or PDCH is the term used to describe the physical layer of the GPRS implementation. It allows for flexible and on demand based allocation of slot numbers. A. GPRS is employed to counter this and handle the data traffic as it employs packet switching. a serving GPRS support node (SGSN) and a gateway GPRS support node (GGSN) are present in GSM/GPRS architecture. For e. packet common control channels (PCCCHs) used to convey the GPRS common control signalling. For e. [6] studied the . which are packet data traffic channels (PDTCHs) used for data transfer. The gateway GPRS support node acts as a gateway between the GPRS and external networks.”[2] 3. and D. K. Past studies were almost totally devoted to this issue. “Different packet data logical channels can camp on the same PDCH. BSS.g. J. Various channel allocation schemes have been proposed in the past schemes have been proposed that we now mention. Two GPRS support nodes (GSNs). VLR. [2] proposed a channel allocation scheme based on the Markov-Modulated Poisson Process (MMPP).which further interacts communicates with the visitor location register (VLR) and home location register (HLR) to keep a track the locations of the mobile stations. which makes the issue of managing and allocating of this resource very critical. GPRS tunnelling protocol is employed by the GPRS support nodes within the same network to transfer user data and other communication related information such as signalling messages. First Fit (FF) and Best Fit (BF). [6] When there is a voice call taking place. The channel allocation scheme employed in this model uses a partial method.1 Sharing In sharing. Priority and Sharing Models The wireless link dimensioning strategy adopted by Marques and Bonatti with voice and data integration has many Quality-of-Service parameters like voice blocking probability. but voice packets having priority over the data packets. Marques and Bonatti [8] have proposed the link dimensioning using circuit-switched voice and packet-switched data. 4. Fig.e. Two different approaches were presented in the paper. They obtain the wireless link dimensioning using an approximation technique that allows the decomposition of the two-dimensional Markov chain. while considering that each PDU could use only a single channel at time. Here C channels are exclusively reserved for use of data traffic while the rest of the channels Cv are shared for both voice and data. 4. [7] proposed two algorithms for channel allocation schemes. the voice services were taken circuit-switched and the data services packet-switched. using 2 one-dimensional Markov chains. the packet loss probability and the average data and voice packet transfer times. In the first. the voice traffic is circuit switched and the data traffic is packet switched.. i. all the channels remain unavailable for use. 2 Figure showing C + Cv channels.GSM/GPRS for a Low-Earth-Orbit (LEO) satellite system. At the end of the conversation they are made available again. In the second both voice and data services are packet-switched. When the channel is being used for the transmission of . The data packets can exclusively use a part of system capacity and share the remaining channels with the voice traffic. Each station has a buffer to store packets and data during such instance. When this happens the remaining bytes of the packet are placed in a buffer and assigned a priority tag and sent as soon as the channel is again made available for transmission. [6] . E{Z} is the average size of the packet. Fig. r =13 Erl. 3 Data packet number probability for: ρv =13 Erl. Conditional model is denoted by a solid line and the Bidimensional Markov chain is denoted by circles. The number of available channels for data traffic is (C + x) with the overall rate of (C + x)γ. The voice calls are generated within average total rate λv having Poisson distribution. The queue M/M/Cv/Cv is used to describe the no. and average service time is 1/µ .a data packet it is unavailable unless a pre-emption takes place due to a voice call. If the buffer is full the packet is dropped. and b =50. where γ is the channel transmission rate. Hence each MS generates packets having Poisson distribution with average total rate λ. of channels taken up by voice traffic. [6] (1) Figure 3 shows data packet number probability in the system for many ν/µv values. having 1/µv as the average service time. The average packet transfer rate here is given by Little’s theorem as given below. For data traffic. The packet transfer rate here is given by the eqn. The packets that have the same priority obey the First-In. First-Out (FIFO) rule to avoid conflict. [6] . 4 Average data transfer time for data traffic.2 Priority In the priority model. [6] (2) 4. r =10 Erl and ρv =10 Erl Fig.4. Voice and data services share a packet-switching server where the transmission rate is (C + Cv)γ and has an infinite buffer. There is now however a priority for voice packets so as to ensure a small delay for them.3 Calculated Results Using set system values Marques and Bonatti derived their observations for both models as observed in conclusion. On using the priority model the number of channels to satisfy the voice blocking probability obtained were enough to accommodate the low data traffic. . This is due to the poor quality estimate of the traffic quality.For voice traffic. There is a small gain in system capacity on using the channel sharing technique when compared to the non-sharing one. The computed average data packet transfer time sensibility to voice or data traffic overload of the nominal capacities with the priority model is smaller than sharing model. Minimal capacities satisfying QoS parameters and the system sensibility to traffic overloads give results that are inversely proportional to each other. When the voice traffic is much bigger than the data traffic it was found that the capacities determined with the priority model were smaller when compared to the sharing model. Both models have their place in different scenarios and both are quite effective. When the voice traffic is bigger than the data traffic the capacities determined with the priority model is smaller when compared to the sharing model. [6] 5. r =10 Erl and ρv =10 Erl Fig. 5 Average transfer time for voice traffic. There are several tradeoffs when wireless link dimensioning is used. 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