S-38.180 Quality of Service in Internet 2cr EXAMINATION 15.11.2004


Answer five out of six questions so that questions 1-2, 3-4 and 5-6 are on separate papers. Put your name, student number, course code and date to each paper. This helps you to receive your credits in fast and reliable manner. Those who do not have Finnish or Swedish as their native language, may answer in English. We will judge the answers based on their quality and clarity. We prefer short and down to the fact answers. You may explain things further but beware that errors may lower your points (even if they are in extra matter).


Good Luck !!!


1) Mitä MPLS-tekniikka on ja mitä sillä voi tehdä? Millä kahdella eri tavalla MPLS voidaan sovittaa toimimaan DiffServ-verkossa?
What is MPLS and what can you do with it? How can you make MPLS work in a DiffServ network (two different ways)? (6 p)

2) Kuvaa IntServ-reitittimen referenssimalli, luettele eroavaisuudet ns. BestEffort-reitittimeen ja kerro IntServ-reitittimen rakenneosien toiminnasta.
Illustrate the reference model of the IntServ router implementation, list the differences compared to a regular BestEffort- router and describe the functionality of the IntServ router blocks. (6p)

3) DiffServ perustuu pakettien eriyttämiseen loogisesti eroteltuihin BestEffort verkkoihin. Mihin tämä eriyttäminen perustuu ja mitä ongelmia tässä mallissa on suhteessa palvelun laadun takaamiseen tai edes relatiivisten laatuluokkien tuottamiseen.
Differentiated Services is based on logical separation of packets into parallel BestEffort networks. To what is this differentiation based and what are the problems related to this model in providing QoS or even relative quality assurances

4) Reitittimillä on välityspolulla kahden tyyppisiä resursseja käytössään, joita ne voivat kontrolloida (eriyttää). Mitä nämä resurssit ovat ja mitkä mekanismit näitä resursseja ohjaavat. Millaisia toteutuksia/algorithms mekanismeille löytyy pääpiirteissään.
Network routers have two resources on their forwarding path which can be controlled (differentiated). What are these resources and what are the functional mechanisms controlling these resources. Mainly what kind of implementations/algorithms there exists for these mechanisms. (6p)

5) Esitä tapoja määritellä pakettien viivejakauma. Mille sovellukselle tai mittaustavalle mikin sopii? Mitä käyttäisit web-selailun yhteydessä?
Describe different methods to describe packet delay distribution. For which applications or measurments each one is most applicable.Which one you would you use with web surfing? (6 p)

6) Millaisia ongelmia TCP:llä on nykyaikaisissa verkoissa? Miten näitä ongelmia on koetettu ratkaista?
What kind of problems there are for TCP in current networks? What kind of solutions there are proposed for these? (6 p)

Mika Ilvesmäki (1-2), Marko Luoma (3-4), Markus Peuhkuri (5-6)

Note: Remember to answer only to five (5) questions!
You must return 3 papers, each group on its own.