Evaluation of Routing Protocols - Essay Example

— When deploying a corporate network for internationally located business offices, there is always a requirement for selecting suitable routing protocols. The selection of routing protocols emphasize on security, reliability, data transmission carrier, efficiency, and robustness. In this scenario, we have a travel agency named as ECC. The company has different branches in different countries. A solution is designed to connect these offices with appropriate topology design, adequate routing protocols and bandwidth carrier that will save bandwidth cost. Index Terms – BGP, EIGRP, OSPF, RIP I. Introduction Wide area network (WAN) spreads itself to multiple distance regions, leading to its expansion across the entire planet. WAN may consists of multiple Local Area Networks (LANs) or Metropolitan Area Networks (MANs). The existence of Internet is constructed on the WAN. Various WAN protocols are deployed for long distance network connectivity. WAN provides the most famous Internet connectivity around the globe. However, some domains of the Internet are considered as WAN. The WAN can be rented from an ISP or privately owned but the technology incorporates public networks.. There are various Internet routing protocols that are implemented to transmit data from one host to another. Due to the complexity and requirements, best protocol selection is required. Secondly, cost and bandwidth considerations are also essential for data delivery. ECC is a travel agency with global presence due to its international branches. There is a requirement of connecting these branches together as they are specifically located at United Kingdom, Hong Kong, Sydney and New York. In order to connect these branches together, a typical WAN design is required along with appropriate routing protocols. II. Wide Area Networks A simple definition of Wide area networks is available in network dictionary states as “A Wide Area Network (WAN) is a computer network covering multiple distance areas, which may spread across the entire world”. In order to make the WAN functional, protocols are used for data transportation, authentication, security, and connectivity. EEC branches are geographically scattered and requires efficient WAN design to cope up the requirements. As the data packets have to pass through several different routers, several decisions are bound to take place by the intelligent routers that are configures for optimal performance. Many protocols are recommended, for effective data delivery, security and most importantly saving bandwidth cost. III. WAN Protocols There are many routing protocols available as they define ‘what a router will do and decided for a specific data packet’. There are two types of routing fundamentals on which these protocols are based, named as Static Routing and Dynamic Routing. The following sections contains advantages and disadvantages of each routing protocol specified along with its administrative distance, metrics, periodic updates, triggered updates, partial updates, VSLM / CIDR subnet masking and algorithms. IV. Routing Information Protocol (RIP) As per network dictionary it is defined as “Routing Information Protocol (RIP) is a standard for exchange of routing information among gateways and hosts. This protocol is most useful as an “interior gateway protocol”. It is also knows as Interior Gateway Protocol (IGP). Frame Relay protocol is implemented for WAN networks associated with LAN internetworking. It functions on physical layer and data link layer of the OSI model, to endow with robust and efficient mechanism for transmitting data. The transmission encompasses multiple routers and switches. Moreover, this protocol is identical to X.25 protocol that activates stations located at the end to share dynamically the network and bandwidth available. Two techniques are associated with Frame relay: As it is based on packet switching, the two techniques are Variable length Packet technique and statistical multiplexing. However, frame relay does not ensure data integrity and drop packets in network congestion issues. Besides, it is considered as a highly reliable data delivery protocol. Frame replay uses virtual circuits as a data communication channel. Virtual circuits that are considered as a logical connection from source to destination. Moreover, these virtual circuits provide two-way communication channels between the uniquely identified terminal devices, identified by Data Link Connection Identifier (DLCI). Furthermore, these virtual circuits can be categorized as Permanent Virtual Circuits (PVCs) and Switched Virtual Circuits (SVCs). PVC’s are configured for a dedicated point-to-point connection and SVC’s are used for normal transmission [2]. On the other hand, Frame Relay protocols have some disadvantages associated with PVCs. The pricing is not effective for PVCs as compared to other PVCs, or else a small amount of incentive will be achieved from changing PVCs to SVCs. Carriers and router vendors were not up to the pace to cope up with frame relay SVC’s, because other routing protocols offer steady and secure PVCs [3]. A. OSPF (Open Shortest Path First) The Open Shortest Path First (OSPF) is associated with interior gateway protocol. It is configured for routing among routers incorporated with a single Autonomous system (AS). Autonomous system is a ginle network or a group of networks, which operates on a sole supervision or administrative control. The Autonomous system may include group of all the computer networks that are owned by an organization or any universities and colleges. there is a possibility that the organization, universities and colleges can own more than one autonomous system. The prime concept is to independently supervise each autonomous system by providing value to BGP. The autonomus system is also reffered as 'A'. OSPF operates on link – state technology that interconnects routers to share information related to each other. Moreover, each router on which OSPF is configured maintains the similar database reflecting the autonomous system’s topology. OSPF redirect packets by using the parameters such as destination IP address which is located at the packet header. OSPF also allows grouping for the sets of networks and the grouping of networks is called an area. However, the Autonomous system cannot identify the topology of this area, and is hidden. The hidden characteristics, eliminates routing traffic significantly. Moreover, only the topology identifies routing in that specific area resulting in minimizing issues due to faulty or dire routing. The OSPF version 2 is optimized only for IP v4 configurations. It supports CIDR and externally derived tagging for routing information. Moreover, it is secure, as it provides authentication and IP multicast. Other features, such as Variable Length Subnet masking (VLSM) are also supported. Furthermore, OSPF version 3 is optimized for IPv6 . When comparing OSPF version 2 with version 3 following additions and modifications are highlighted : 1. The removal of addressing semantics is considered from OSPF data packets along with the basic LSAs. 2. The development of new LSAs is conducted to carry addresses and prefixes associated with IPv6. 3. Instead of a per IP subnet basis, OSPF functions on a peer link basis. 4. Generalization for the flooding scope of LSA's is considered. 5. Previously OSPF relies on IPv6 encapsulation security payload and authentication header. Authentication has now been removed from the OSPF protocol. B. Enhanced interior Gateway Routing Protocol (EIGRP) EIGRP is a Cisco proprietary protocol that operates via advance distant vector. This protocol executes ‘hello’ protocol in order to maintain relationships with the neighbor routers. Moreover, EIGRP transmits a complete routing table in the startup phase and whenever there is a modification in the routing table, it triggers partial updates on a multicast IP address i.e. 224.0.0.10. Furthermore, EIGRP is a classless protocol that supports authentication, robust communication, stores backups for best routes in order to use them in future, and uses Diffusion Update Algorithm (DUAL) to compute routing updates. If the query packets fails to update the routers and no backup is maintained in the topology table, alternates routes are requested in order to establish a separate valid route in the routing table. EIGRP maintains an administrative distance for internal routes is 90 and for external routes 170. In addition, EIGRP has the capability to recognize internal and external routes along with impartial load balancing support. C. Border Gateway Protocol (BGP) The prime functionality of BGP is to exchange routing information between Autonomous Systems (AS) and maintains a list of every AS that has been processed. Moreover, BGP encompasses basic algorithm known as the path vector algorithm to provide loop free topology. D. T3 In order to connect the geographically located branches, T3 connectivity from the local office to the ISP is recommended. T3 connectivity possesses many features, making it a choice for high-speed data networks. T3 supports data transmission speed up to 43.232 Mbps, which is equal to 28 T1 lines. The outrageous bandwidth capacity provides the freedom to integrate streaming video and data transmission of large data files or multimedia contents. High bandwidth capacity makes T3 a good option for corporate businesses, universities and colleges as large amount of digitized data is shared among the networks. In fact, the carrier for T3 digital signals is fiber optics. However, media convertor is required to convert the fiber optic interface in to an Ethernet interface. The expandable feature for having T3 connectivity is that it provides more than 672 simultaneous connections. If any issue occurs in T3 connectivity, it is quickly diagnosed and corrected by using remote diagnostics features. V. Future Developments Research is conducted on routing protocols associated with IPv4 and are now transformed with new features in the IPv6 domain. E. RIPng RIPng is also an interior gateway protocol, which is designed for use with IPv6. Previous versions that are available in IPv4 are RIP and RIPv2 [8]. Moreover, some added features are as follows [8]: 1. RIPng do not deploy authentication to data packets. F. OSPF A research was conducted by comparing MPLS protection switching versus OSPF rerouting. The results for this comparison highlight two significant factors that need to be improved. Interior routing architecture needs improvement in order to augment Forwarding information Base (FIB) updates. Consequently, the second factor is to boost the failure detection mechanism. There are the two factors that requires improvement in OSPF [9]. G. Enhanced interior Gateway Routing Protocol (EIGRP) Future developments for EIGRP are the scaling of hubs and spokes for Dynamic Multipoint Virtual Private Network (DMVPN). Support for both IPv4 and IPv6. The integration of Service Advertisement Framework (SAF) that is based on EIGRP technology and Call agent discovery. VI. Design of ECC Network As ECC is geographically dispersed having different branches in Hong Kong, Singapore, New York and London that is further allocated in three more branches i.e. Birmingham branch, Edinburgh branch and Cardiff branch. The objecting is to design a topology to connect all these branches and sub branches via a dedicated, secure, reliable and robust network connectivity. The hurdle to overcome is the bandwidth cost and the selection of Internet Service Providers in different regions. As shown in Figure 1.1, Hong Kong network is connected to the Singapore network, which is also acting as a network gateway for Hong Kong network. Moreover, the branches in UK are sharing VPN connectivity with each other and are communicating with the London HQ branch that is acting as a gateway. Due to its bandwidth capacity and fault tolerance, preferred connection is ADSL T3 that is acting as a virtual link. Furthermore, routers for UK branches are configured with OSPF and IBGP. These protocols are establishing connectivity with branches as well as with the London HQ. Routers located at London HQ are also configured with BGP and OSPF in order to support intra and inter-domain routing. As EIGRP shares some characteristics and architecture that are Cisco proprietary, may cause limitations in terms of scalability factors resulting in restrictions for network deployment associated with future growth of the network. Fig. 1.1. VII. Conclusion In this course work, we have evaluated different routing protocols including RIP, OSPF, BGP and EIGRP. As per the scenario, we have selected best routing protocols in order to save bandwidth cost, main adequate security, and reliable connectivity throughout the Wide area network. References [1] Wide Area Network. 2007. Network Dictionary, , pp. 525-525. [2] Protocols Guide: Wide Area Network and WAN Protocols: Other WAN Protocols: Frame Relay: WAN Protocol for Internetworking. 2007. Javvin Technologies, Inc, pp. 171-172. [3] BUCKWALTER, J.T., Frame relay: technology and practice Reading, Mass. ; Addison-Wesley, c2000. [4] Autonomous System. Available: http://www.inetdaemon.com/tutorials/internet/ip/routing/bgp/operation/autonomous_system.shtml [4/3/2011]. [5] Protocols Guide: TCP/IP Protocols: Network Layer Protocols: Routing Protocols: OSPF: Open Shortest Path First protocol. 2007. Javvin Technologies, Inc, pp. 62-63. [6] Networking 101: Understanding iBGP. Available: http://www.enterprisenetworkingplanet.com/netsp/article.php/3617346/Networking-101--Understanding-iBGP.htm [4/3/2011, 2011]. [7] T3 Internet? Definition and Advantages . Available: http://www.worldnet-long-distance.com/blog/t3/t3-internet/ [4/3/ 2011]. [8] RIPng Overview. Available: http://www.juniper.net/techpubs/software/junos/junos64/swconfig64-routing/html/ripng-overview.html [4/14/2011]. [9] SOLE-PARETA, J., SMIRNOV, M., MIEGHEM, P.V., DOMINGO-PASCUAL, J., MONTEIRO, E., REICHL, P., STILLER, B. and GIBBENS, R.J., Quality of Service in the Emerging Networking Panorama : 5th International Workshop on Quality of Future Internet Services, QofIS 2004, and WQoSR 2004 ... (Lecture Notes in Computer Science) Springer. Read More