The article covers

• Selecting the software for VPN
• Client-Servers
• VPN Server
• Hardware and software for VPN Client

VPN’s and the choice of the type of VPN depend on the user requirements. The many questions you need to ask before selecting the software for VPN is

• Is VPN software to configure general purpose file servers cheap?
• Can the correct protocols and applications be configured on my present system to make it connect to a VPN?
• Should I rely on routers and other dedicated hardware?

Lower costs is a plus when you already have an operating system that supports VPN. Most operating systems’ software for windows have the necessary capability to configure and run a VPN.

Each network is unique with it’s owns set of users and user’s permissions, so an evaluation of the VPN product in relation to your infrastructure is needed to make a choice. Network architectures are of two types; Peer-to-peer or client-server.

Peer-to-peer network is where all computers on the network provide resources and computing power. As the nodes increase in a network the demand of network capacity is divided between the individual computers. This increases robustness of the system and prevents failures.

Client-Servers

Client-Server Network architecture is where the PC is the requesting machine and the server the supplying machine. These two computers are connected via a network either LAN or WAN. The client can process some or all of the application process. The server maintains a data base and process requests from the client to extract database or to update he database. Additional processing is provided in case the server is an application server. Servers can be of ordinary personal computers to mainframes. Servers in a LAN perform a variety of tasks. They are files servers, printer server, Mail servers, X compute servers, Application-specific servers, Database-specific servers, System boot servers and General-purpose compute servers

• File Servers manages a work group’s application and data files, so that they may be shared by the group. File servers require many slots for network connections, large-capacity and a fast hard disk subsystem.
• Compute Server does application logic processing. It requires high performance capabilities with a large amount of memory.
• Database Server is the most typical use of technology in client-server. In this mode the servers accepts requests for data, retrieves the data from its database and passes the results back. The server requirement depends on the size of database, the number of users, the type of network and the speed with which the database must be updated.
• Communication Server provides gateway to other LANs, networks & Computers. It also works as E-mail Server and internet server. It requires multiple slots and a fast processor to translate networking protocols

These client server systems are mostly used for commercial applications like

• Finance and administrative applications
• World Wide Web servers
• Video and document servers
• Online transaction processing
• Batch processing

In a Client server Relationship most of the applications are done on the client side and the model is that of a master slave configuration. The internet has largely evolved on the client server model. The users are still clients who run the browser and the server uses a multi-tier architecture of interlinked web servers and database servers that provide us the information in the form of HTML pages.

VPN Server

VPN server software is not needed as VPN software for Windows based workstations or Servers have VPN capability incorporated in the operating systems. As for other operating systems special software cater to VPN functionality. Moreton Bay’s PoPToP software can convert any ordinary PC into a server based PC. Many corporations realize that after setting up the architectures of their network and other privileges and assignments that the weakest part in the security is the humans who do not have complete knowledge of the security of the system.

• Complete Knowledge of Server based Networking (intranet and extranet) is needed.
• Utilize the existing user and group assignments and privileges. This simplifies administration.
• Security should be the main factor as worms and other cyber attacks on server based systems are numerous.
• Vigilance is constantly needed as there are many points of attack in a network and access at any point compromises almost the entire network. Routine checks of log files are needed to know if your system was subject to unauthorized access.
• If you have a large amount of clients then a dedicated single system for VPN services is better or other services on the corporate network will slow down.
• The scalability is limited as when compared to additional hardware solution. Windows NT server 4.0 can support only 256 simultaneous VPN tunnels.
• In case of buying additional software see if the VPN solution is supported by server based network operating system.

Continue to: Hardware and software for VPN Client