Question: What protocol is used as the basis for the HTTP-1 reference point between the HTTP client and the HTTP proxy in Mission Critical Services, with optional security enhancements?
Option 1: FTP (File Transfer Protocol) with optional SSH (Secure Shell)
Option 2: TCP (Transmission Control Protocol) with optional IPsec
Option 3: SIP (Session Initiation Protocol) with optional S/MIME (Secure/Multipurpose Internet Mail Extensions)
Option 4: HTTP (Hypertext Transfer Protocol) with optional SSL/TLS (Secure Sockets Layer/Transport Layer Security)
Explanation: In the context of Mission Critical Services, the HTTP-1 reference point leverages HTTP as its foundational protocol, aligning with web-based service architectures. The optional use of SSL/TLS for security ensures encrypted communication, making Option 4 the most accurate choice for secure and reliable mission-critical communications.