Properties of the network for data transmission based on IP protocol.
Macura, Arijana
1. INTRODUCTION
Modern communication networks are using exclusively Internet
Protocol ( IP ). The IP protocol was developed in an attempt to enable
building up of the public network infrastructure which can support a
large numbers of nodes. For this reason, the key feature of the IP
protocol is precisely extendibility (scalability). Network based on IP
protocol, adhere to the fundamental principle of construction of
computer protocols defined in the model of open systems connection (OSI model-Open System Interconnection). IP protocol is the base the public
telecommunication networks construction. All other properties are
required from such a network must adapt to the IP protocol, that is they
must exploit some of standard methods available in the IP protocol to
ensure security, expandability, transport isolation and quality of
service (Williamson, 1999). It is therefore necessary to know the way in
which the IP protocol and networks built on that protocol work. The
network must support data transmission through the use of IP protocol,
must contain the nucleus whose task is the transfer of large amount of
data in an efficient manner with assurance of quality of services, and
access part using which the connection with clients has been created.
Supervision and management is also a key part of any public network for
data transmission. There are rules to build the core and network access
part, which delivers optimal solutions with respect to the capacity of
the network, the type and amount of users, quality of service, etc.
2. INTERNET PROTOCOL
The IP protocol is the basis of the construction of the public
telecommunication network. All other properties which are required from
such network must adapt to IP protocol, that is must exploit some of
standard methods available in the IP protocol to ensure security,
expandibility, transmission isolation, and services quality. For that
reason, it is necessary to know the way IP and network constructed on
the basis of this protocol work, as well as the transmission properties
which can occur in the networks constructed in such a way. That is
package protocol without connection what means that all information are
transmitted between nodes in packages and that between the end
destinations is not established a direct communication channel. Nodes
within the IP network are virtually connected, each node has its address
on the basis of which any other node can direct towards it packages. A
special header is added to the packages, which contains all information
by which the network can decide how to direct an individual package up
to end destination. The most important information within the IP header
are the source and destination address. The source does not know in
advance which way the package will use to pass through the network,
neither can it guarantee that the package will successfully reach the
destination. Each router will independently decide where to forward the
IP package at the moment of package arrival on basis of the best
currently available data. Information about where to direct the traffic
towards particular destination is called a route. Routing table contains
a series of routes that determine direction to all available
destinations (Halabi, 2000). Dynamically filling routing table gives an
additional advantage in what IP routers can be aware of network topology and on basis decide on which interface to forward an IP package. The
principle of work of the IP protocol is shown in Figure 1. This
principle has been selected because it provides exceptional flexibility
and scalability of traffic routing. Successful communication in the IP
networks presumes adjustment of all types of data transmission by means
of the IP protocol. Development of IP has been flowing parallel with
development of B-ISDN model, and conditions within the telecommunication
industry have led to its universal applications in all types of network.
Telecommunication networks on one side have been building a very
elaborated and conceived B-ISDN which was the most exemplary model for
use in the public telecommunication networks. On the other side, end
users have built their networks on the basis of universally available,
extendable and cheap IP standard. The end users, who require that the
telecommunication networks support directly IP protocol that is highly
represented in their networks were victorious. Besides that, the basic
properties of the IP protocols are directly adapted to the building up
of large public networks which enable communication between a large
numbers of nodes. The popularity of Internet results in a number of new
challenges.
[FIGURE 1 OMITTED]
3. TCP PROTOCOL
The self similar and long range dependent TCP/IP traffic is mainly
caused by new complex interactions between protocols and technologies
and by other information transported by voice. (Van Miegham, 2006). TCP
protocol can be found at the transport layer of OSI model and is
responsible for ensuring the correct transmission of data between two
end points in the IP network ( IP does not guarantee the correct
transmission ). Beside that, the TCP performs an additional function
that is traffic control and jam prevention. In order to recognize
different communication sessions between the various destinations it
applies special TCP header which is added to each IP package after the
IP header. Among the properties which the TCP posses in order to ensure
safe transfer and there is a relatively sophisticated mechanism for
traffic control. The sending of traffic in the TCP protocol is based on
the principle of sliding window. The nodes signalize to each other data
about which package has been received directly and how many more
packages can be sent prior to arrival of the next confirmation of
reception. By expanding or reducing of windows it is effectively the
quantity of data in transmission, and thus indirectly also the speed of
communication (Boudani et al., 2004). The size of windows represents
data quantity which the source can send without the confirmation of
reception. Sending speed is determined on the basis of rhytm of the
confirmation of receipt, because the knot that sends, knows how fast the
receiver receives packages on the basis of rhytm in which the
confirmation of receipt comes back. The more the rhytm is faster, the
greater the speed by which the sender can send the transmission. That
speed increases to the moment in which receipt information lacks. The
lack of confirmation of receipt signalizes that somewhere in the
communication channel occurred congestion and because of that the sent
package did not arrived back to the source. In reality, the TCP source
at the beginning sending traffic exponentially increases the amount of
data sent after each receipt confirmation up to the limit of exponential
growth, after which linearly increases the amount of data sent to the
limit of maximal windows size. As soon as a confirmation of receipt
lack, source reduces the amount of sent traffic to the half, after which
the previously described mechanism of windows increase activates. The
principle of work is shown in Figure 2.
[FIGURE 2 OMITTED]
4. UDP PROTOCOL
A special protocol is used for an efficient and simple data
transfer through the IP network for transfer of users ' packages
(UDP-User Datagram Protocol) (Boudani & Cousin, 2003). Its
functionality is very simple: a package of data that should be sent is
made, to that package is added the UDP header, which consists of the
number of source and of the destination port, then such package is
directed to the destination. The UDP ports are necessary in order to
identify unambiguously the source and destination application which
exchange transmission between them. UDP does not have any mechanism to
check off if the reception of a package is correct, not the mechanism to
repeat the sending in case of data loss, or the mechanism of controlling
traffic flow. For that reason the UDP will send the traffic with
determined speed, regardless of the availability of resources. This kind
of traffic is called inelastic traffic. Since it is one-way traffic,
standard mechanism of traffic control is useless. It means that the IP
network must ensure data reception in sequence, under strict control of
timing of transmission parameters, congestion solving and control of
packages loss. This protocol is extremely useful for multimedia
applications that need at an efficient way send large amount of
transmission which required a transfer in real time respecting limit of
delays and delays variations. The effectiveness of the UDP protocol for
multimedia applications in function of limits of delays and variations
of delays will be carried out within further research.
5. CONCLUSION
In this work has been set the fact that in modern networks the IP
protocol is the base of service integration. The basic task of the IP
protocol as of the protocol of network layer is to ensure communication
between end destinations in the global communication network. The
protocol as such does not represent any additional properties of such
communication as the speed and quality of service, and along with that
it works properly when applied to any technology of data and physical
layer. The basic property of the protocol the extendibility that is
scalability is sufficiently strong principle on which it is possible to
build very sophisticated global communication network. For this reason,
as well as for the fact of open protocol, the IP has got huge popularity
in all kinds of communication network and put out all other application
concept.
6. REFERENCES
Boudani, A. & Cousin, B. (2003). A New Small Multicast Routing
Protocol, the 10th International Conference on Telecommunications,
February 2003, Tahiti, French Polynesy
Boudani, A.; Guitton, A.& Cousin, B. (2004). Generalized
Explicit Multicast Routing Protocol, The 9th IEEE Symposium on Computers
and Communications, June 2004, Alexandria, Egypt
Halabi, S.(2000). Internet Routing Architecture, Cisco Press,
ISBN-13:978-1-57870-233-6; Indianapolis, SAD
Van Miegham, P. (2006). Performance Analysis of Communications
Networks and Systems, Cambridge University Press, The Edinburgh Building
ISBN 978-0521-10873-7, Cambridge CB2 8RU, UK
Williamson, B. (1999). Developing IP Multicast Networks, Volume I,
Cisco Press ISBN-10: 1-5787-077-9, Indianapolis, SAD
*** (2009). http://www.google.com--William Paterson University of
New Jersey, Communications, a monthly journal published by ACM, Accessed
on: 2009-04-14
