Knowledge Bank

What is IP address used for?

IP Address is used for network devices identification in the IP network. Let’s have a look at it like it will be a traditional post. We are buying an envelope (carrier), writing a letter (content), place the content into this envelope (addressing for the recipient) and we bring this envelope to the post office (the media). We hope that this letter will reach its destination then. Additionally we place sender details on the back of this envelope in case of something was wrong and the letter can’t be delivered to its recipient. It gives a possibility to return this letter to the sender.

This is very similar to the idea of IP network in case of idea. The difference is in data representation (letter vs. digital message) and the time the message need to reach its destination (days vs. miliseconds). IP network is a media where data packages are sent. Size of the packages are adjusted to the media character.

Let’s say we have written a message in e-mail software like Outlook or Thunderbird. This letter contains of couple a4 size pages. To send this letter, apropriate engines have to split it into smaller pieces, pack into network packets and send to the recipient through the network. When the recipient receive these pieces, he have to reassemble them into the complete letter. So he need to know what was the the splitting order. This is done using sequence number which is attached to every network packet.

So every packet has its source IP address (sender address), destination IP address (recipient address) and additional information which is needed to make transmission beetween sender and recipient. If there will be two equal IP addresses in the network, then transmission errors will occure. So the IP addresses should be unique.

Internet Access Technologies

The Internet access can be established using various technologies simply called "last mile". Below are informations about all of them.

Internet access technologies articles

DSL

The DSL (Digital Subscriber Line) technology allowed the fast growth of the Internet and popularisation of on-line services. The classic modem connection (dial-up Internet access) provides the 56 kbps speed. Read more...


ADSL

This is the most popular version of the DSL technology used by many providers. It differs from the less common symmetric link (SDSL). The ADSL provides wider bandwidth for the transmission towards customer (i.e. downlink) than in the reverse direction (i.e. uplink). Read more...


VDSL

The VDSL is the hybrid technology which combines the fibber and the cooper media. The fibbers are used in the operator network and so-called the last mile (i.e. the connection between the nearest provider’s device and the customer) is covered by the cooper line. Read more...


WiFi

WiFi is a trademark term for the IEEE 802.11 family standards. The first 802.11 standard was released in 1997 and it was providing up to 2 Mbps wireless link speed. It was slow, but it was the first technology which has allowed to connect several computers in the local area network without cables. Read more...


LTE - Long Term Evolution

LTE stands for Long Term Evolution and it is commonly marketed as 4G LTE. This is the standard of mobile wireless communication which provides high transmission speeds, low latency and high network capacity. Read more...


LAN over power line

Nowadays, practically every home and small office local area network use the WiFi as an access technology. Sometimes, also the classical Ethernet cables are used, but their application is uncomfortable and messy. Read more...


Digital Video Broadcast (DVB)

The most popular family standard of digital television is the DVB (Digital Video Broadcast). These standards are maintained by the DVB Project and are published by the European Telecommunications Standards Institute (ETSI). Read more...


Local Area Network (LAN)

LAN (Local Area Network) is a computer network which provides the connectivity between hosts (i.e. computers) located within a limited area, e.g. home, office, school, university campus etc. The LAN can be connected to the WAN (Wide Area Network), which covers a larger geographic area.Read more...


Mobile Communication Systems

The most popular mobile communication system is GSM (Global System for Mobile Communications). This is worldwide used second-generation (2G) cellular system which replaced first-generation (1G) analogue systems (e.g. NMT – Nordic Mobile Telephone). Read more...