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Міністерство освіти і науки

Одеська національна академія звязку ім. О.С. Попова

Третя міжнародна науково-практична конференція молодих вчених
ІНФОКОМУНІКАЦІЇ – СУЧАСНІСТЬ

ТА МАЙБУТНЄ”


17-18 жовтня 2013 року


Збірник тез
Частина 2

Одеса


ОНАЗ

2013


УДК 621.39:004.9


Інфокомунікації – сучасність та майбутнє: матеріали третьої міжнар. наук.-пр. конф. молодих вчених м. Одеса 17-18 жовт. 2013 р. – Ч.2. – Одеса, ОНАЗ, 2013. – 176 с.
ISBN 978-617-582-003-2

Даний збірник містить тези матеріалів, що представлені на третю міжнародну науково-практичну конференцію молодих вчених “Інфокомунікації – сучасність та майбутнє”, що проводиться 17-18 жовтня 2013 р. в Одеській національній академії звязку ім. О.С. Попова.


У збірник включені тези доповідей за такими напрямками:

– інформаційні мережі та технології;

– програмне забезпечення мереж зв’язку та телемедицина;

– проблеми економіки та управління у сфері інфокомунікацій.



Робочі мови конференції – українська, російська, англійська.


ISBN 978-617-582-003-2  ОНАЗ ім. О.С. Попова, 2013

Програмний комітет

Воробієнко П.П.

голова, д.т.н., проф., ректор ОНАЗ ім. О.С. Попова

Каптур В.А.

заступник голови, к.т.н., проректор з наукової роботи ОНАЗ ім. О.С. Попова

Стрелковська І.В.

заступник голови, д.т.н., проф., декан факультету Інфокомунікацій ОНАЗ ім. О.С. Попова


Організаційний комітет

Антонов О.С.

доцент кафедри КІТ ПіВ ОНАЗ ім. О.С. Попова

Балан М.М.

к.т.н., доцент кафедри „Інформаційної безпеки та передачи даних” ОНАЗ ім. О.С. Попова

Беркман Л.Н.

д.т.н., професор, завідувач кафедрою „Телекомунікаційні системи” Державного університету інфокомунікаційних технологій

Бобровнича Н.С.

к.е.н., доц., зав. каф. УП та СА ОНАЗ ім. О.С. Попова

Бондаренко О.М.

к.ф.н., доц., відповідальна за наукову роботу ННІЕМ ОНАЗ ім. О.С. Попова

Васіліу Є.В.

д.т.н., директор Навчально-наукового інституту Радіо, телебачення та електроніки ОНАЗ ім. О.С. Попова

Захарченко Л.А.

директор Навчально-наукового інституту Економіки та Менеджменту ОНАЗ ім. О.С. Попова, к.е.н., доцент

Калінчак О.В.

к.е.н., доц., зав. каф. ЕТ ОНАЗ ім. О.С. Попова

Климаш М.М.

д.т.н., професор кафедри „Телекому­нікації” Національного університету „Львівська політехніка”

Ларін Д.Г.

к.т.н, доц. каф. ІТ ОНАЗ ім. О.С. Попова

Лемешко О.В.

д.т.н. професор кафедри телекомуникаційних систем, ХНУРЕ

Лісовий І.П.

д.т.н., професор кафедри телекомунікаційних систем ОНАЗ ім. О.С. Попова

Ложковський А.Г.

д.т.н., проф., завідувач кафедрою комутаційних систем ОНАЗ ім. О.С. Попова

Нікітюк Л.А.

к.т.н., проф., завідувач кафедрою „Мережі зв’язку” ОНАЗ ім. О.С. Попова

Орлов В.М.

д.е.н., проф., зав. каф. ЕП та КУ ОНАЗ ім. О.С. Попова

Поповський В.В.

д.т.н., проф., завідувач кафедрою „Телекомунікаційні системи та ме­ре­жі” Харківського національного уні­верситету радіоелектроніки

Проценко М.Б.

д.т.н., проф., завідувач кафедрою технічної електродинаміки та систем радіозв’язку ОНАЗ ім. О.С. Попова

Розенвассер Д.М.

відп. за наукову роботу факультету ІК ОНАЗ ім. О.С. Попова

Семенко А.І.

д.т.н., професор кафедри „Телекомунікаційні системи” Державного університету інфокомунікаційних технологій

Стрельчук Є.М.

к.е.н., проф., зав. каф. М та М ОНАЗ ім. О.С. Попова;

Сукачов Е.О.

д.т.н., професор кафедри „Технічної електродинаміки та систем радіозв’язку” ОНАЗ ім. О.С. Попова

Сундучков К.С.

д.т.н., професор кафедри „Інформаційно-телекомунікаційних мереж” НТУУ «КПІ»

Тіхонов В.І.

к.т.н., доц, доцент кафедри „Мережi зв’язку” ОНАЗ ім. О.С. Попова

Уривський Л.О.

д.т.н., проф., завідувач кафедрою «Телекомунікаційні системи» Інституту телекомунікаційних систем НТУУ «КПІ»

Хіхловська І.В.

д.т.н., доц., декан факультету Заочного навчання ОНАЗ ім. О.С. Попова

Чорний Ю.П.

заст. дек. факультету Заочного навчання ОНАЗ ім. О.С. Попова

UDK 519.74, 681.51

Roland Akwari

ONAT named after O.C. Popov

vinitime@yahoo.com
RESEARCHING OF RIP ROUTING PROTOCOL
Abstract. The simplicity of the Routing Information Protocol is often given as the main reason for its popularity. Simplicity is great most of the time, but an unfortunate “price” of simplicity in too many cases is that problems crop up, usually in unusual cases or special situations. And so it is with RIP: the straight-forward distance-vector algorithm and operation mechanism work well most of the time, but they have some important weaknesses. 
1. Introduction

Problems with RIP’s Basic Algorithm and Implementation: The most important area where we find serious issues with RIP is with the basic function of the distance-vector algorithm described earlier in this section, and the way that messages are used to implement it. They are four main problems here: slow convergence, routing loops, “counting to infinity” and “small infinity”.



RIP is a routing protocol based on the Bellman-Ford (or distance vector) algorithm [2]. This algorithm has been used for routing computations in computer networks since the early days of the ARPANET. The particular packet formats and protocol described here are based on the program "routed," which is included with the Berkeley distribution of Unix

In an international network, such as the Internet, it is very unlikely that a single routing protocol will used for the entire network. Rather, the network will be organized as a collection of Autonomous Systems (AS), each of which will, in general, be administered by a single entity.



OSPF ( Engl.  Open Shortest Path First ) - the Dynamic routing based on the technology of monitoring the status of the channel (link-state technology) and is used for finding the shortest path Dijkstra (Dijkstra's algorithm). The OSPF protocol was developed by IETF in 1988. The latest version of the protocol is presented in RFC 2328 . The OSPF protocol is an interior gateway protocol (Interior Gateway Protocol - IGP ). 

Border Gateway Protocol (BGP) is the protocol which is used to make core routing decisions on the Internet; it involves a table of IP networks or "prefixes" which designate network reachability among autonomous systems (AS). BGP is a path vector protocol or a variant of a Distance-vector routing protocol. BGP does not involve traditional Interior Gateway Protocol (IGP) metrics, but routing decisions are made based on path, network policies and/or rule-sets. For this reason, it is more appropriately termed a reachability protocol rather than routing protocol.

BGP was created to replace the Exterior Gateway Protocol (EGP) to allow fully decentralized routing in order to transition from the core ARPANET model to a decentralized system that included the NSFNET backbone and its associated regional networks. This allowed the Internet to become a truly decentralized system. Since 1994, version four of the BGP has been in use on the Internet. All previous versions are now obsolete. The major enhancement in version 4 was support of Classless Inter-Domain Routing and use of route aggregation to decrease the size of routings. Since January 2006, version 4 is codified in RFC 4271, which went through more than 20 drafts based on the earlier RFC 1771 version 4. RFC 4271 version corrected a number of errors, clarified ambiguities and brought the RFC much closer to industry practices.


2. Comparing different dynamic routing protocols:

Below is table 1 showing the difference between several dynamic routing protocols:


Table1 – Comparing dynamic routing protocols

Protocol

Advantages

Disadvantages

Uses

RIP

Configuration is simple.

• RIP v2 can communicate with an external network.



Convergence is relatively

slow.


• Metric is based only on hop count.

• If used to connect to an ISP, the ISP must redistribute the

routes into BGP.


• LANs

• Simple WANs

• Connecting to an external network

• Not used over dial-up

Connections


OSPF

• Accurate routes take link speed and cost into account.

• Convergence is fast.

• Overhead is as low as RIP if the network is well-designed


• Configuration is complicated.

• Overhead can be high.

• OSPF cannot be used as an

EGP without redistribution



• More extensive LANs and

WANs


• Not used over dial-up

Connections



BGP

• ISPs use BGP.

• BGP provides tight control over which routes are advertised and

accepted.

• Overhead is relatively low



• Configuration is complicated.

• The network must also run an IGP.



• Connecting to an ISP

• Not used over dial-up connections




3. The algorithm, structure and operation of RIP protocol.

Protocol RIP (Routing Information Protocol, Routing Information Protocol) is the simplest dynamic routing protocol. It refers to the protocols of the "distance-vector"[1].

Under the vector of the RIP protocol defines IP-address of the networks, and the distance is measured in the transitions ("hopah”, hope) - the number of routers that a packet must pass to reach the specified network. It should be noted that the maximum distance for the RIP is 15, a value of 16 is interpreted in a special way, "network is unreachable". It has defined the main disadvantage of the protocol - it is inapplicable in large networks where possible routes in excess of 15 hops.

RIP version 1 has some significant drawbacks for practical use. Among the important issues are the following:



The estimate of distance only based on the number of transitions. RIP protocol does not account for the actual performance of communication channels that can be effective in heterogeneous networks, i.e. networks of different communication channels linking the device performance, which use different network technologies.

The problem of slow convergence. Routers Use the protocol RIP. Send out routing information every 30 seconds, and their work is not synchronized. In a situation where some router detects that any network is unreachable, then in the worst case (if the problem was detected immediately after the regular newsletter) he would report it to neighbors 30 seconds later. For all neighboring routers will also take place. This means that information about the inaccessibility of a network router may be distributed in a sufficiently long time, it is obvious that in this network will be in an inconsistent state.

Broadcast routing tables. RIP is initially assumed that the routers send out information in broadcast mode. This means that the package you send is forced to receive and analyze the data link, network and transport layers all the computers on the network to which it is directed.

Algorithm: Distance vector algorithms are based on the exchange of only a small amount of information [3]. Each entity (router or host) that participates in the routing protocol is assumed to keep information about all of the destinations within the system. Generally, information about all entities connected to on network is summarized by a single entry, which describes the route to all destinations on that network. This summarization is possible because as far as IP is concerned, routing within a network is invisible. Each entry in this routing database includes the next router to which datagrams destined for the entity should be sent. In addition, it includes a "metric" measuring the total distance to the entity.

Structure of a RIP packet: It is hard to fully understand a routing protocol without knowing what information is carried in its packets. Knowing what information is exchanged between routers and how will help you better understand the RIP protocol, and better configure your network for it.

This section provides information on the contents of RIP 1 and RIP 2 packets [4].

RIP version 1, or RIP IP packets are 24 bytes in length, with some empty areas left for future expansion.

1-byte command

1-byte version

2-byte zero field

2-byte AFI

2-byte zero field




4-byte IP address

4-byte zero field

4-byte zero field

4-byte metric

RIP version 2 has more features than RIP 1, which is reflected in its packets which carry more information. All but one of the empty zero fields in RIP 1 packets are used in RIP 2.



1-byte

command



1-byte

version



2-byte

unused



2-byte

AFI



2-byte

route tag




4-byte IP address

4-byte

subnet



4-byte

next hop



4-byte metric


4. Model of router in IP network
In Figure 1 represents the model of router port with static routing table in colored Petri Nets form.

Figure 1 – Model of router port with static routing table


The purpose of the next researching is constructing the model of IP network with dynamic routing and RIP protocol in colored Petri Nets form. The transitions In* model the processing of input frames. The frame is extracted from the input buffer only in cases where the routing table contains a record with an address that equals to the destination address of the frame (dst=target); during the frame displacement the target port number (port) is stored in the buffer. The transitions Out* model the displacement of routed frames to the output ports’ buffers. The inscriptions of input arcs check the number of the port. The fixed time delays (@+5) are assigned to the operations of the routing and the writing of the frame to the output buffer [5].
Reference

  1. RFC 2092- protocol analysis for triggered RIP.

  2. RFC 1058- routing information protocol.

  3. RFC 2453- G. Makin Bay network.

  4. Vladimir Pleshakov- Cisco internetworking technology overview.

  5. D.A. Zaitsev, T.R. Shmeleva. Simulating of Telecommunication Systems with CPN Tools. Students’ book. –Odessa, ONAT, 2006, 62p.



УДК 621.391

  1. Батіст О.О.

  2. ОНАЗ ім. О.С. Попова

  3. oli.batist@gmail.com

  4. Науковий керівник доц. Тіхонов В.І.


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