Designing a fault tolerant and secure network core for inter-organization communication

Sammanfattning: Service providers which provide services within customers’ networks often deal with the issue of needing to use a large number of VPN accounts and RSA tokens to access customers’ networks. One service provider (SP) has solved this by setting up an inter-organizational communication network (IOCN) to facilitate access to customer places systems. This system has out grown its original setup.  Research on network architectures is abundant but there is very limited research focusing on IOCNs. The aim of this thesis has been to contribute to the lack of that research by intending to redesign the above mentioned IOCN with focus on ensuring network security and fault tolerance. This was done by analyzing the existing IOCN, evaluating its flaws with regards to network security and fault tolerance and finally suggesting a new setup based on the original infrastructure. The solution has been generalized to be adaptable to the needs of any service provider. The infrastructure has been setup with a cascading firewall structure increasing security by using generalized rules on the outer firewalls and specifying rules further in to the network.