The company called Nexco is looking to secure all forms of communication between Site A and Site B. They have approached you, as a professional with expertise in network security, to provide some insight and advise on how this can be achieved. The main idea is that they are looking to implement a layered approach of network security. Seeing that you have completed the Network Security course, you have to consider the different techniques you learned about to typically achieve reasonable communication security between Site A and Site B. It is important that you consider the following scope: 

1. Site A and Site B are separated geographically, and thus all communications must traverse the Internet; (a) Communication in this case means all types of communication as highlighted during this course. This may include, amongst others, emails, ftp, web service, accessing of servers on both sites, and any other related communication between Site A and Site B. 

 2. The question is not HOW they should setup network security, in other words details of configurations and actual setting up of solutions, but rather WHAT they should do to ensure reasonable communications security between Site A and Site B. 

With the scope in mind, consider the following instructions and the associated weighting: 

1. Explain what combinations of security protocols & techniques Nexco can utilise on each of the layers of the TCP/IP model (Layer 1 to Layer 4) to provide reasonable communication security; 

2. For each mentioned protocol & technique, it is important to consider the context of the scenario. Therefore explain why this particular protocol & technique is applicable and necessary. In other words, provide justification of why it is important, and how it can help to reduce certain risks to communication security; . 

3. How will your suggestions and advice change if, instead of using the Internet for communication, a dedicated line was acquired by Nexco?; 

4. Formatting, references, structure and professional look of answer document.