Strategic Relation between Business Imperatives and Router Functionality:
It is difficult to imagine that if there is any relation that exists between the business imperatives and improvised router functionality, but as the matter of fact it is there. Many business strategists have researched and concluded the point by mapping that the business imperative drive a number of technical strategies. It is a fact that routers can be linked to the business imperatives, this is because for the emerging business needs, IT organisations
will need to expand their network and to have a connection between the enterprises and their branches, there is a need to expand their existing network infrastructure by deploying VPN at each branch with the router in between the main organisation and branch VPN, such that they can share their resources along a secure path. Therefore to deploy a VPN for a new branch for the existing organisation, routers are the connection bridges between them.
The figure below shows how the business imperatives are linked to the technical strategies of the systematic arrangement. It shows how the technical strategies are linked to business imperatives. From figure, it can be seen that the topmost priority initiatives include:
- Centralization and Consolidation: To improve the effectiveness and oneness in the organisation, it is better to move all the information and resources from the branch offices to a centralised data centres and combining the data centres to the branch offices. The idea of Centralisation and Consolidation helps the realtime in the following ways,
- Make or become better control over information resources
- Cost elimination by again unnecessarily of resources at each virtual system.
- Improves the management of resources, by placing the resources in a more closely managed environment.
- Network virtualisation (Virtualization of Servers, Storages, Desktops and networks) using application: Virtualisation of devices in the network greatly become less cost needed to deploy hardware devices in the network.
- Optimized power usage: The hardware device uses power and generates some the quality of being hot. There is a need to manage and optimise the network conditions not only at the data centres but also at the remote centre's. There is a virtual logical hardware installed in the network, which runs on s/w application.
- Reduced network Complexity: With the implementation of virtual device application in the network, such as a router to connect the main data centre with the remote data centres, In this way reduces network complexity.
- Improved operational Efficiency: As the virtualisation of devices leads to a smaller extent; not so much complexity in the network, easily seen or understood the managing of the devices in the network will be very easy. It also improves the operational efficiency in the network by allowing able to be change in size or scale options for the enterprise.(Jim Metzler, 2009)
The implementation of network virtualisation also improves the network performance. However the concept can only be achieved if the WAN traffic to have less delay.
Therefore with the above factors that are discussed and represented above, Implementing new technology on an already exiting weak infrastructure may result in disastrous outputs. The designed network must also adapt to the ever-changing needs of business and availability as the changes will certainly occur. The concept also reduces the complexity that may arise with the network deployment, implementation and also while re-engineering the network.
Fundamentals of Virtual Routing
In fundamentals of virtual routing provides a detaild overview of all the components that make up the concept of virtual network. It describes the infrastructure of VPNs and MPLS based VPNs. It also details how the routing takes place in the network and also the importance and functionality of the router while routing the network traffic in the network. How the routing is done and how and where the virtual routers can be placed in the MPLS based VPN network are briefly discussed in this chapter
Virtual Private Network:
The networks in the internet increases one particular part is very harder to reach, the network security. With the increase of internet there is a steep increase in public networks. With Internet being termed as 'Network or Networks' (Nagumantri, 2006), it is made up of public networks with the process of private networks. The network in an office area is called Intranet (Bialous, 2006) and connecting these intranets make up VPN. In order to solve the network security issue, one solution to retain the security as well as the data communication, is the implementation of VPN or Virtual Private Networks. VPNs are normally use effectively in organizations, industries, vital sectors such as banking, government sectors etc, colleges and universities etc., where the security threat is always about happen.
The network is said to be designed in such a way that users access inside and outside the network as well, but outside computers view it as a single computer and cannot access the resources within the network. (Tyson, 2007).The starting objective of Virtual private network is that intranet computers which are inside the organization can access the intranet, internet make easy and can also share data with other belief in the reliability truth VPN network which are outside the VPN, using internet connectivity. This type of concept is called tunnelling and will be discussed in the forthcoming sections. VPN also makes sure that outside computers to access any intranet facilities.
Mostly every organization use VPN or virtual private network architecture which within the network allows top level departments to access and share the information from highly secure computers or servers, but lower departments in an organization may not be access them, because of priority based security issue. This is called Virtual private network. (Tyson, 2001). There are different types of VPN, which can be designed and deployed based on the network specifications (Daniel and Ravi, 2005).
The VPN may contain many number of routers to manage and direct information in the secured network and outside the network. The routers are generally placed the intranets in the organization and outside network, which is also called as VPN router. These routers are generally called as CE (Customer Edge) routers which are shown in the figure. The ViPnet co-coordinators are nothing but CE routers, It can be placed strategically in between the branch office and the main data centre. These CE routers are the main connection between the remote data centres and the main branches. The CE routers use tunnelling concept and protocols frequently meet to share the data between the branch and the main data centre.
The idea of VPN is to provide starting data from the main office to the branches through secure only access with in the organization but not out side's. This concept of accessing network resources from outside or from the other secure intranets is done by a secure line called as tunnel The figure is shown below. (Gleeson, 2000)
Each and every sub branch's connected to the main branch data centre intranet through these tunnels. This type of tunnelling concept is suitable for the connection oriented not able to be relied upon IP packet transport. Therefore tunnelling concept is not suitable for connectionless reliable IP transport, since packet header is identifying something to the data packet.
MPLS (Multi Protocol Label Switching);
A Multi Protocol Label Switching is a network switching technology that has been proposed by the CISCO networking group of companies. The theory was actually proposed by Ipsilon, a networking based company, it's only for ATM networks only. So CISCO networking based company evaluated the research and applied this concept onto the Ethernet networks.
The concept of MPLS is so simple, in conventional IP routing, as the data packets are sent form initial computer. In order to reach the correct destination, IP routing connecting packet header to each data packet it has created and sends the packet onto the network. Then the routers that encounter the data packets analyzes the packet header and checks up the router network table. The router then checks the shortest possible path for the data packet to reach the destination successfully. MPLS on other hand is a very different and is not a routing protocol. The MPLS technology effectively add to the end of the document a label to the data packet and is sent onto the network. The routers along the network, instead of checking and in detail so as to explain it the entire packet and its header, it just reads the label and forwards the packet. This type of technology worked producing an intended result on the VPN networks other than the normal Internet network, where quality of service is priority rather than prompt delivery.
In the above diagram clearly tells the MPLS network works. The PE routers are Provider Edge routers that contain routing protocols such as OSPF (open shortest path first), POP (post Office Protocol). The VPN - based MPLS network (Morrissey, 2000)managing traffic inside and outside. OSPF protocols maintain security in the MPLS based VPN network by implementing the show to be authentic process the in network, i.e. all the employees in the industry will have authentication code with which they can access data initial from the network. However this access as usual is based upon the priority with high level employees are given the maximum control over the data content.
To optimize the network, device virtualisation can be used, in this MPLS network since the network use more routers to route the data over the network, and the router virtualisation can be applied. More about routers are its applications are briefed in next section.
The MPLS network contains two routers one at the start of VPN-MPLS network and another one within the network. The one which is outside the network is called PE or provider edge router and the router inside the network is called CE (Customer Edge) router. The PE router sits at the end of the network, where as the CE router is located within the customer VPN (LAN) network which provides Ethernet interface between customers's LAN and the ISP network (Ipinfusion. 2002). The P (provider) routers are located at the core of Internet Service Provider ISP network and the PE routers sits at the edge of the network. In the figure below shows the full architecture of the MPLS network relationship to customer's VPN network.
Below are the fundamental concepts of networks that are used to apply the concept of virtual routing. This section illustrates all the fundamental concepts involved in virtual routing and brief descriptions of routing algorithms are discussed below,
we can see that the MPLS based network configurations are being used by the Internet Service Providers. The provider edge routers connect to CE routers which reside at the core of the VPN networks. The ISP can provide Ethernet facilities to more than one VPN. In any protocol stack. The figure below. There are some protocols in the stack that allow the top layer protocols to exchange the information with the lower layer protocols and some protocols that allows the whole stack to communicate with other devices . i.e. how the packet will reach its destination, which path should the packet take to reach its destination, what is the condition of the network etc. (Medhi and Ramaswamy, 2007)
The accepted code of behaviour in a particular situation are generally used by the routers to mutual understanding and route the traffic inside the network. Another protocol that is used by the router is the ICMP protocol, which is an abbreviation of Internet Control Message Protocol. which may be a router or a workstation to indicate that the packet has not reached its target or to inform the last routing device there is a problem in the network such as congestion in the network, which allows the routing device to take an alternate path to reach the packet's destination (Alexandrou, 2009).
BGP or border gateway protocols play an important role in BGP/ MPLS based VPNS. The protocol that is mainly used is IPSec, which is responsible for security purposes as it the protocol is designed for authenticating and encrypting IP packet over the network to maintains security in the network.
The Internet Protocol version four or IPv4 uses the standard ICMP protocol version where as the newest Internet Protocol version 6 or IPv6 uses ICMPv6 which is an extended version of ICMP supporting IPv6 configuration.