Telecom Switches Routers

multicast packet deals with and routers

suppose a group of machines have the same ip address like 60.4.4.4 so router can send the packet to that network but here the every node will take care to deliver the packets to target (multiple routers) there is no need that grand parent(main sender) will take care of all family members wether they got the food(data packets) here the grand children (which is not directly with sender ) food(data packets) send by his children of grand parent(which is directly connected with the sender) so here router send the data to packets and all the nodes send the packets to the a physical address link up with that ip

unicast also deals with routers it will deals with one-to-one connection every parent have the direct relation with child

Short for port-switching hub, a special type of hub that

forwards packets to the appropriate port based on the

packet's address. Conventional hubs simply rebroadcast

every packet to every port. Since switching hubs forward

each packet only to the required port, they provide much

better performance. Most switching hubs also support load

balancing, so that ports are dynamically reassigned to

different LAN segments based on traffic patterns.

Some newer switching hubs support both traditional Ethernet

(10 Mbps) and Fast Ethernet (100 Mbps) ports. This enables

the administrator to establish a dedicated, Fast Ethernet

channel for high-traffic devices such as servers.

Bridging is a forwarding technique used in packet-switched computer networks. Unlike routing,

bridging makes no assumptions about where in a network a particular address is located. Instead,

it depends on flooding and examination of source addresses in received packet headers to locate

unknown devices. Once a device has been located, its location is recorded in a table where the

MAC address is stored so as to preclude the need for further broadcasting. The utility of bridging

is limited by its dependence on flooding, and is thus only used in local area networks.

Bridging generally refers to Transparent bridging or Learning bridge operation which

predominates in Ethernet. Another form of bridging, Source route bridging, was developed for

token ring networks.

A network bridge connects multiple network segments at the data link layer (Layer 2) of the OSI

model. In Ethernet networks, the term bridge formally means a device that behaves according to

the IEEE 802.1D standard. A bridge and switch are very much alike; a switch being a bridge with

numerous ports. Switch or Layer 2 switch is often used interchangeably with bridge.

Bridges are similar to repeaters or network hubs, devices that connect network segments at the

physical layer (Layer 1) of the OSI model; however, with bridging, traffic from one network is

managed rather than simply rebroadcast to adjacent network segments. Bridges are more

complex than hubs or repeaters. Bridges can analyze incoming data packets to determine if the

bridge is able to send the given packet to another segment of the network.

Auto-negotiation is a mechanism that takes control of the

cable when a connection is established to a network device.

Auto-negotiation detects the various modes that exist in

the device on the other end of the wire, and advertises it

own abilities to automatically configure the highest

performance mode of interoperation.

Auto-negotiation automatically switches to the correct

technology, such as 10BASE-T, 100BASE-TX, or a

corresponding Full Duplex mode. Once the highest

performance common mode is determined, Auto-negotiation

passes control of the cable to the appropriate technology

and becomes transparent until the connection is broken.

A switch, keeps a record of the MAC addresses of all the

devices connected to it. With this information, a switch

can identify which system is sitting on which port. So when

a frame is received, it knows exactly which port to send it

to, which significantly increases network response times.

And, unlike a Hub, a 10/100Mbps switch will allocate a full

10/100Mbps to each of its ports. So regardless of the

number of PCs transmitting, users will always have access

to the maximum amount of bandwidth. It's for these reasons

why a switch is considered to be a much better choice then

a hub.

Routers are completely different creatures. Where a hub or

switch is concerned with transmitting frames, a router's

job, as its name implies, is to route packets to other

networks until that packet ultimately reaches its

destination. One of the key features of a packet is that it

not only contains data, but the destination address of

where it's going.

A router is typically connected to at least two networks,

commonly two LANs or WANs or a LAN and its ISP's network

(ex. your pc or workgroup and EarthLink). Routers are

located at gateways, the places where two or more networks

connect. Using headers and forwarding tables, routers

determine the best path for forwarding the packets. Routers

use protocols such as ICMP to communicate with each other

and configure the best route between any two hosts.

A router will typically include a 4-to-8 port Ethernet

switch (or hub) and a Network Address Translator (NAT). In

addition, they usually include a Dynamic Host Configuration

Protocol (DHCP) server, Domain Name Service (DNS) proxy

server and a hardware firewall to protect the Local Area

Network (LAN) from malicious intrusion from the Internet.

In a hub, a frame is passed along or "broadcast" to every

one of its ports. It doesn't matter that the frame is only

destined for one port. The hub has no way of distinguishing

which port a frame should be sent to. Passing it along to

every port ensures that it will reach its intended

destination. This places a lot of traffic on the network

and can lead to poor network response times.

Additionally, a 10/100Mbps hub must share its bandwidth

with each and every one of its ports. So when only one PC

is broadcasting, it will have access to the maximum

available bandwidth. If, however, multiple PCs are

broadcasting, then that bandwidth will need to be divided

between all of those systems, which will degrade

performance.

A switch, on the other hand, keeps a record of the MAC

addresses of all the devices connected to it. With this

information, a switch can identify which system is sitting

on which port. So when a frame is received, it knows

exactly which port to send it to, which significantly

increases network response times. And, unlike a Hub, a

10/100Mbps switch will allocate a full 10/100Mbps to each

of its ports. So regardless of the number of PCs

transmitting, users will always have access to the maximum

amount of bandwidth. It's for these reasons