Telnet is also called as terminal emulation.
It belongs to application layer.
Signals are usually transmitted over some
transmission media that are broadly classified in to two categories:-
Guided Media:
These are those that provide a conduit from one device to another that include twisted-pair, coaxial cable and fiber-optic cable. A signal traveling along any of these media is directed and is contained by the physical limits of the medium. Twisted-pair and coaxial cable use metallic that accept and transport signals in the form of electrical current. Optical fiber is a glass or plastic cable that accepts and transports signals in the form of light.
Unguided Media:
This is the wireless media that transport electromagnetic waves without using a physical conductor. Signals are broadcast either through air. This is done through radio communication, satellite communication and cellular telephony.
Guided Media:
These are those that provide a conduit from one device to another that include twisted-pair, coaxial cable and fiber-optic cable. A signal traveling along any of these media is directed and is contained by the physical limits of the medium. Twisted-pair and coaxial cable use metallic that accept and transport signals in the form of electrical current. Optical fiber is a glass or plastic cable that accepts and transports signals in the form of light.
Unguided Media:
This is the wireless media that transport electromagnetic waves without using a physical conductor. Signals are broadcast either through air. This is done through radio communication, satellite communication and cellular telephony.
Server-based network.
Peer-to-peer network.
Peer-to-peer network, computers can act as both servers sharing resources and as clients using the resources.
Server-based networks provide centralized control of network resources and rely on server computers to provide security and network administration.
Peer-to-peer network.
Peer-to-peer network, computers can act as both servers sharing resources and as clients using the resources.
Server-based networks provide centralized control of network resources and rely on server computers to provide security and network administration.
Series of interface points that allow other
computers to communicate with the other layers of network protocol stack is
called SAP.
Sending a message to a group is called
multicasting, and its routing algorithm is called multicast routing.
Routable protocols can work with a router and
can be used to build large networks. Non-Routable protocols are designed to
work on small, local networks and cannot be used with a router.
Request to Exit (REX) - A signal that informs
the controller that someone has requested to exit from a secure area.
Repeater:
Also called a regenerator, it is an electronic device that operates only at physical layer. It receives the signal in the network before it becomes weak, regenerates the original bit pattern and puts the refreshed copy back in to the link.
Bridges:
These operate both in the physical and data link layers of LANs of same type. They divide a larger network in to smaller segments. They contain logic that allow them to keep the traffic for each segment separate and thus are repeaters that relay a frame only the side of the segment containing the intended recipient and control congestion.
Routers:
They relay packets among multiple interconnected networks (i.e. LANs of different type). They operate in the physical, data link and network layers. They contain software that enable them to determine which of the several possible paths is the best for a particular transmission. Gateways: They relay packets among networks that have different protocols (e.g. between a LAN and a WAN). They accept a packet formatted for one protocol and convert it to a packet formatted for another protocol before forwarding it. They operate in all seven layers of the OSI model.
Also called a regenerator, it is an electronic device that operates only at physical layer. It receives the signal in the network before it becomes weak, regenerates the original bit pattern and puts the refreshed copy back in to the link.
Bridges:
These operate both in the physical and data link layers of LANs of same type. They divide a larger network in to smaller segments. They contain logic that allow them to keep the traffic for each segment separate and thus are repeaters that relay a frame only the side of the segment containing the intended recipient and control congestion.
Routers:
They relay packets among multiple interconnected networks (i.e. LANs of different type). They operate in the physical, data link and network layers. They contain software that enable them to determine which of the several possible paths is the best for a particular transmission. Gateways: They relay packets among networks that have different protocols (e.g. between a LAN and a WAN). They accept a packet formatted for one protocol and convert it to a packet formatted for another protocol before forwarding it. They operate in all seven layers of the OSI model.
Redirector is software that intercepts file or
prints I/O requests and translates them into network requests. This comes under
presentation layer.
Packet filter is a standard router equipped
with some extra functionality. The extra functionality allows every incoming or
outgoing packet to be inspected. Packets meeting some criterion are forwarded
normally. Those that fail the test are dropped.
One of two sublayers of the data link layer of
OSI reference model, as defined by the IEEE 802 standard. This sublayer is
responsible for maintaining the link between computers when they are sending
data across the physical network connection.
One of the main causes of congestion is that
traffic is often busy. If hosts could be made to transmit at a uniform rate,
congestion would be less common. Another open loop method to help manage
congestion is forcing the packet to be transmitted at a more predictable rate.
This is called traffic shaping.
NETBIOS is a programming interface that allows
I/O requests to be sent to and received from a remote computer and it hides the
networking hardware from applications.
NETBEUI is NetBIOS extended user interface. A transport protocol designed by Microsoft and IBM for the use on small subnets.
NETBEUI is NetBIOS extended user interface. A transport protocol designed by Microsoft and IBM for the use on small subnets.
It provides a framework for discussing network
operations and design.
is using a router to answer ARP requests. This
will be done when the originating host believes that a destination is local,
when in fact is lies beyond router.
It is the protocol the routers in neighboring
autonomous systems use to identify the set of networks that can be reached
within or via each autonomous system
It is any routing protocol used within an
autonomous system.
It is an Internet routing protocol that scales
well, can route traffic along multiple paths, and uses knowledge of an
Internet's topology to make accurate routing decisions.
It is an authentication service developed at
the Massachusetts Institute of Technology. Kerberos uses encryption to prevent
intruders from discovering passwords and gaining unauthorized access to files.
It is a very simple protocol used for
transmission of IP datagrams across a serial line.
It is a system that performs a protocol
translation between different electronic mail delivery protocols.
It is a simple protocol used to exchange
information between the routers.
It is a set of rules defining a very simple
virtual terminal interaction. The NVT is used in the start of a Telnet session.
It is a sequence of IP addresses identifying
the route a datagram must follow. A source route may optionally be included in
an IP datagram header.
It is a protocol used to advertise the set of
networks that can be reached with in an autonomous system. BGP enables this
information to be shared with the autonomous system. This is newer than EGP
(Exterior Gateway Protocol).
It is a protocol formerly used to exchange
routing information between Internet core routers.
It is a project started by IEEE to set
standards that enable intercommunication between equipment from a variety of
manufacturers. It is a way for specifying functions of the physical layer, the
data link layer and to some extent the network layer to allow for inter
connectivity of major LAN protocols.
It consists of the following:
802.1 is an inter networking standard for compatibility of different LANs and MANs across protocols.
802.2 Logical link control (LLC) is the upper sublayer of the data link layer which is non-architecture-specific, that is remains the same for all IEEE-defined LANs. Media access control (MAC) is the lower sublayer of the data link layer that contains some distinct modules each carrying proprietary information specific to the LAN product being used. The modules are
Ethernet LAN (802.3), Token ring LAN (802.4), Token bus LAN (802.5).
802.6 is distributed queue dual bus (DQDB) designed to be used in MANs.
It consists of the following:
802.1 is an inter networking standard for compatibility of different LANs and MANs across protocols.
802.2 Logical link control (LLC) is the upper sublayer of the data link layer which is non-architecture-specific, that is remains the same for all IEEE-defined LANs. Media access control (MAC) is the lower sublayer of the data link layer that contains some distinct modules each carrying proprietary information specific to the LAN product being used. The modules are
Ethernet LAN (802.3), Token ring LAN (802.4), Token bus LAN (802.5).
802.6 is distributed queue dual bus (DQDB) designed to be used in MANs.
It is a problem that can ruin TCP performance.
This problem occurs when data are passed to the sending TCP entity in large
blocks, but an interactive application on the receiving side reads 1 byte at a
time.
It is a host that has a multiple network
interfaces and that requires multiple IP addresses is called as a Multi-homed
Host.
It is a collection of routers under the
control of a single administrative authority and that uses a common Interior
Gateway Protocol.
