Application Layer Protocols

Application layer protocols are a set of protocols that are responsible for providing services to the end-users. These protocols define how data is formatted, transmitted, and interpreted between different software applications. They operate at the topmost layer of the TCP/IP protocol suite, which is the application layer. Some examples of application layer protocols include HTTP, FTP, SMTP, DNS, etc.

Explanation of Options

Let's analyze each option to determine which one is not an application layer protocol:

a) Media Gateway Protocol (MGP): Media Gateway Protocol is an application layer protocol that is used to control and manage media gateways in a Voice over IP (VoIP) network. It is responsible for the setup, maintenance, and teardown of media sessions between media gateways. Therefore, MGP is an application layer protocol.

b) Dynamic Host Configuration Protocol (DHCP): Dynamic Host Configuration Protocol is an application layer protocol that is used to dynamically assign IP addresses and other network configuration parameters to devices on a network. DHCP operates using a client-server model, where a DHCP server provides the necessary configuration information to DHCP clients. Therefore, DHCP is an application layer protocol.

c) Resource Reservation Protocol (RSVP): Resource Reservation Protocol is not an application layer protocol. RSVP is a network layer protocol that is used to reserve network resources (such as bandwidth) in an IP network. It operates at the network layer, which is below the application layer. Therefore, RSVP is not an application layer protocol.

d) Session Initiation Protocol (SIP): Session Initiation Protocol is an application layer protocol that is used to establish, modify, and terminate real-time sessions between participants. It is commonly used in VoIP and video conferencing applications. Therefore, SIP is an application layer protocol.

Conclusion

Among the given options, the correct answer is option 'c', which states that Resource Reservation Protocol (RSVP) is not an application layer protocol. RSVP is a network layer protocol used for resource reservation, while the remaining options (MGP, DHCP, and SIP) are all application layer protocols.