Simple Network Management protocol is a framework used for managing devices on internet using the TCP/IP protocol suit.Its a application level protocol and provides set of fundamental operations for  monitoring and maintaining on internet.It uses the concept of agent and manager.A manager is a host, that controls and monitors a set of agents therfore it is correct.

NFS stands for Network File System. It allows a system to share directories and files with others over a network. By using NFS, users and programs can access files on remote systems almost as if they were local files.

Every device has a dedicated point to point link to every other device. Dedicated means that, the link carries traffic only between the two devices it connects. Therefore, mesh topology provides bidirectional links between each possible nodes.

The standard connector for unshielded twisted pair cabling is a RJ-45 connector. This is a plastic connector that looks like a large telephone-style connector.

The most common type of connector used with coaxial cables is the Bayone-Neill-Concelman (BNC) connector. Different types of adapters are available for BNC connectors, including a T-connector, barrel connector and terminator. Connectors on the cable are the weakest points in any network.

It is the shortest frame which consists of flag, address, control, FCS and it carries commands and responses.

Coaxial cabling has a single copper conductor at its centre. A plastic layer provides insulation between the centre conductor and a braided metal shield. The metal shield helps to block any outside interference, therefore we use it in CABLE TV. Thin coaxial cable is known as thinnet (10base2). The most common ones are RG 59(Coaxial cable) and a low loss cable is RG 6, both are 72 ohm for TV sets and antennas.

 FTP, SFTP and TFTP are used for transferring files from one system to another through internet and web server. FTP  is a standard network protocol used to copy a file from one host to another over a TCP -based network, such as the Internet. The SSH File Transfer Protocol is not related to FTP except that it also transfers files and has a similar command set for users. A similar protocol TFTP (Trivial File Transfer Protocol) provides connectionless file transfer over UDP.This is only suitable for very small files; for example, uploading configuration files to routers. 

BNC are the T-shaped connectors, used to connect the cable, at two ends and NIC's .

Data link control is a bit oriented protocol for managing the flow of information in a data communication system.

Broadband LAN uses frequency division multiplexing on a coaxial cable to exchange information.

Photodiode is used at a receiving end of an optical fiber. They convert optical signals back into electrical impulses that are used by the receiving end of the fiber optic data, video or audio link.

It has a multiring functionality, so we can say, it looks like a FDDI. Both species 100 mbps token passing rings, two rings and one ring for a backbone.

X.25 is a subset of HDLC protocol. It enables to form a logical link connection, besides all the other characterstics of HDLC.

Cryptography is a science of securing information in the network. It converts information into some other format which would not be understood by an unauthorized person.