EP1008255A1

EP1008255A1 - Arrangement in a data transmission system, especially an internet system

Info

Publication number: EP1008255A1
Application number: EP98937881A
Authority: EP
Inventors: Kevin Kliland; Knut Snorre Bach Corneliussen
Original assignee: Telefonaktiebolaget LM Ericsson AB
Current assignee: Telefonaktiebolaget LM Ericsson AB
Priority date: 1997-08-29
Filing date: 1998-08-04
Publication date: 2000-06-14
Also published as: AU8652498A; NO973977L; NO312738B1; WO1999012321A1; NO973977D0

Abstract

The present invention relates to an arrangement in a data transmission system, especially an internet system, in which system data is transmitted between terminals and servers with a certain level of QoS (Quality of Service) on IP (Internet Protocol), and in order to provide an arrangement wherein selection of QoS on IP can be effected in an efficient manner, it is according to the invention suggested that said system comprises at least two server means (I, II), and means for transferring data between connected terminals, for example a client terminal (III), and said server means (I, II), as well as between said server means (I, II), for thereby changing, respectively improving said QoS level.

Description

ARRANGEMENT IN A DATA TRANSMISSION SYSTEM, ESPECIALLY AN INTERNET SYSTEM

FIELD OF THE INVENTION

The present invention relates to an arrangement in a data transmission system, especially an internet system, in which system data is transmitted between terminals and servers with a certain level of QoS (Quality of Service) on IP (Internet Protocol) .

In other words, the inventions relates to QoS settings on IP using web technology.

TECHNICAL BACKGROUND

The problem

Today no known and widespread solutions exist for select- ing QoS on IP, hence applications running on e.g. TCP or UDP on IP, hardly have the ability to provide QoS to its application and hence users. This means that the quality of e.g. real time applications running in such an environment probably will be poor.

E.g. ATM provides powerful mechanisms for QoS selection on specified connections (or flows), but as long as IP, or the commonly used upper layer protocols don't provide such mechanism, the applications are not given the abil- ity to select QoS.

Known solutions RSVP over ATM

RSVP is located above the IP layer and provide simple mechanism for selecting QoS on specified IP flows. As described above, ATM has incorporated the QoS conception, There is a standard, see reference 2, which states the QoS mapping for RSVP versus ATM. The main drawback with this solution is that the RSVP protocol not yet is widespread. Probably it will take some time before it becomes widespread partly due to that it has to be implemented both at the client, server and router side. The RSVP standards are not yet stable either.

Arequipa Arequipa provides QoS on IP over ATM by using a Web browser. For information on this particular solution, see reference 1.

The main drawbacks with this solution is that proprietary and modified Web browsers, Web servers and OS (currently linux) are used.

EP 0 132 835 A2

European patent EP 0 732 835 A2 proposes a way to utilize internet for signalling and PSTN, or network with PSTN functionality, for real connections. Also security and charging mechanisms are included. The client establishes a so called communication number when signalling. This communication number is later utilized for setting up the real connection over PSTN or a similar network.

A drawback by this solution is that dedicated client code has to be installed on every client. Besides, and most important, QoS on IP or internet and hereby possibilities for internet applications to utilize QoS, is not touched.

OBJECTS OF THE INVENTION

The main object of the present invention is to provide an arrangement in a data communication system wherein QoS on

IP can be changed, respectively improved according to appropriate user settings . Another object of the present invention is to provide an arrangement wherein the quality of e.g. real time applications can be changed to an appropriate level .

Still another object of the present invention is to provide an arrangement wherein such change of quality can be implemented by using for example web technology.

SUMMARY OF THE INVENTION

These objects are achieved in an arrangement of the type as stated in the preamble, which according to the present invention is characterized by che features as stated in the characterizing clause of the enclosed patent claim 1.

Further features and advantages of the present invention will appear from the following description taken in con- juction with the enclosed drawings, as well as from the further enclosed patent claims.

BRIEF DISCLOSURE OF THE DRAWINGS

Fig. 1 is a schematic sketch illustrating an embodiment of the present invention as well as the key concepts thereof .

Fig. 2 is a schematic sketch illustrating in further details an example of an embodiment of the present invention, especially for implementing QoS on IP over ATM.

DETAILED DESCRIPTION OF EMBODIMENTS

Key concepts

The key concepts of the invention is first of all the usage of 2 set of servers means, for example web server means, as well as the possibility of transferring data between terminals, for example browsers, and servers, as well as between servers.

As a non-limiting example of realizing the invention by using for example web technology, such implementation can involve :

_• One Web server is running on IP/MAC. It is dedicated for the selection of new Web pages providing services with a corresponding QoS, hence this may be considered to be the signalling part.

_• The other Web server (-s) run IP over whatever, e.g. ATM, and provide the requested services and corre- sponding QoS to the user. Which protocols IP may run on is dependent on what kind of network that is available. Even the PSTN may be the base network. If a phone, modem and TAPI are available, IP and HTTP may be running on top of TAPI. Naturally, the under- lying network may introduce limitations with respect to available QoS parameters.

_• When the internet Web server and the QoS dedicated Web server resides on the same server (-computer), they must be given different IP addresses, see chap- ter "Precondition". Almost the same applies on the client side, i.e. the client ATM card and the client MAC card must be given different IP addresses.

In Figure 1 there are illustrated the key concepts of the invention by means of order: A Web server I connected to the internet, a Web server II connected to the network providing QoS and some dedicated server code has to be installed on the server (-computer ( -s) ) . Further the client has to install a Web browser III. When this is configured, a client may perform the signalling part by utilizing the internet, the Web browser III and the internet Web server I. Thereby the connection establish- ment is performed by utilizing the network providing QoS, the Web browser III and the QoS dedicated Web server II. Hence the client has established a connection providing QoS between the Web browser III and the QoS dedicated Web server II.

An example which illustrates the invention Figure 2 gives an illustration of a possible concrete implementation of QoS on IP by using Web technology. In this example IP is running over ATM in a Classical IP, see reference 4, environment.

In other words, Figure 2 illustrates an embodiment for implementing QoS on IP over ATM by using Classical IP over ATM and 2 Web servers I and II, respectively. Note that also the ordinary DNS and IP/MAC ARP server resides on the server (-computer) .

Stepwise guide to Figure 2 : a) The server (-computer) registrates and provides its ATM and IP address to the ATM ARP server b) The client registrates and provides its ATM and IP address to the ATM ARP server c) The client downloads the MAC Web server page. The ordinary MAC/IP ARP is used. d) The client selects the QoS parameters it wants for the coming ATM connection. If the client is going to select Servicel, the client has to utilize QoSl . The QoS data may be transferred to the MAC Web server e.g. by CGI scripts or Java applets/RMI, hence some server (-computer) code must be executing. e) The MAC Web server must in turn transfer the QoS parameters and the client's IP address to the ATM Web server Servicel resides at. Generally, Java/RMI or Java/CORBA may be applied to transfer these data from the MAC Web server to the ATM Web server. In this example where both Web servers reside on the same computer, remote distribution mechanisms are superfluous, only a simple e.g. Java program is needed. f) Immediately after the ATM Web server has received all the data, it initiates the setup of an ATM connection with the specified QoS parameters towards the client. Either an ATM card API or a script utilizing the command shell may be used to initiate the ATM connection. g) The ATM Web server requests the ATM ARP server of the client's ATM address, receives the client's ATM address, performs the signalling with the specified QoS parameters and sets up the ATM connection towards the client . h) The client requests the ATM Web server page by clicking on Servicel which is the ATM Web server's URL. The DNS server will in turn return the ATM Web server's IP address.

NB : Note that the server (-computer) program must be made in a way that ensures that the ATM connection exists before the downloading of the new Servicel ATM Web page starts. i) The client requests the ATM ARP server of the ATM Web server's ATM address and receives data about the already existing ATM connection. As stated in chapter "Precondition", the first attempt to retrieve the ATM server address was done by asking the ordinary IP/MAC ARP server. ) The client receives the requested Web page on the already existing ATM connection. The ATM Web page may be downloaded in the already opened Ethernet browser or as depicted in the figure, be downloaded in a new ATM browser. k) By the time the connection has been idle for a specified time, the server (-computer) program tears down the ATM connection.

Notes to Figure 2 :

_• Even though only the simple scenario where both the

Web servers and the ATMARP servers resides on the same server (-computer), the same approach could be applied on a full scale Classical IP including routers, dedicated ARP servers, DNS servers and Web servers residing at completely different servers (-computers) .

_• Only one ATM browser is illustrated. Several ATM browsers could however simultaneously be running on the same time on different connections. Alter- natively, as briefly already mentioned the same browser could be used to both IP/MAC and IP/ATM connections, hence the active connection instantly would appear in the browser.

_• The HTTP protocol is not well suited to run video application and similar real time applications which ATM is good at. Hence to utilize ATM and the invention in general, the co ing RTSP, which is an alternative to HTTP, is better suited.

Precondition

A precondition and a part of the invention when it comes to the server (-computer (-s)) and client side, is that the underlying network cards, in this example ATM adapter cards, are given an IP address (which is mapped towards the ATM adapter card) which is different from the ordinary IP address (which is mapped towards the MAC card) . The different IP addresses are used to differentiate between the different underlying networks. This technique is used under i) above. E.g. FORE, see reference 3, has implemented such an approach when it comes to IP over MAC and IP over ATM.

Advantages The advantage of the depicted scenario and the invention is simply that users are given the possibility to select services, e.g. Web pages with a wanted QoS by using standard hardware and software. Some additional server (-com- puter) code is all that is needed.

Broadendinα

The invention with respect to ATM as the underlying net- work, could as well be applied on LANE (Local Area Network Emulation) and NHRP (Next Hop Resolution Protocol) , and other appropriate protocols .

Abbreviations _• QoS (Quality Of Service) .

_• IP (Internet Protocol) .

_• TCP (Transport Control Protocol) . TCP runs on top of IP.

_• UDP (User Datagram Protocol) . UDP runs on cop of IP. _• ATM (Asynchronous Transport Mode) .

_• RSVP (Resource Reservation Protocol) . By RSVP it is possible to set up flows, that may e.g. be a connection between a client and a server, with (guaranteed-) QoS. RSVP runs on top of IP. . OS (Operating System) .

_• MAC (Media Access Control) . Here used as a reference to the low level Ethernet protocol which runs below IP.

_• MAC address . Here used as a reference to the phyical address of a Ethernet card.

_• PSTN (Public Switched Telephone Network) . The ordinary telephone system.

_• TAPI (Telephone Application Programming Interface) . An interface which makes it possible for plain com- puter programs to communicate with the phone system.

_• HTTP (Hypertext Transport Protocol) . This protocol is running on top of TCP and is the protocol used for data exchange between Web browsers and servers .

_• RTSP (Real Time Streaming Protocol) . This protocol is an alternative to HTTP due to HTTP's bad characteristics when it comes to streaming/real time applications .

_• RTP (Real Time Protocol) . RTP is running on top of IP and is used for real time applications.

_• DNS (Domain Name Server) . DNS translates a domain name to an IP address.

_• IP/MAC ARP server translates an IP address to a MAC address .

_• ATM ARP server translates and ATM address to an IP address . _• CGI (Common Gateway Interface) . A script facility to transport data from the client to the server.

References

[1] URL: http://lrcwww.epfl.ch/arequipa [2] Interoperation of Controlled-Load and Guaran- teed-Service with ATM. Borden M. and Garret M. Internet draft.

[3] ForeRunner SBA-200 ATM SBus Adapter.

[4] Classical IP and ARP over ATM. RFC 1577.

Claims

P a t e n t c l a i m s

1. Arrangement in a data transmission system, especially an internet system, in which system data is transmit- ted between terminals and servers with a certain level of QoS (Quality of Service) on IP (Internet Protocol) , c h a r a c t e r i z e d i n that said system comprises at least two server means (I, II), for example web server means, and means for transfering data between con- nected terminals, for example a client terminal (III), and said server means (I, II), as well as between said server means (I, II), for thereby changing, respectively improving said QoS level .

2. Arrangment as claimed in claim 1, c h a r a c t e r i z e d i n that a first of said server means (I) is running on IP, which in turn may be running on e.g. MAC (Media Access Control) or PPP (Point to Point Protocol) or any other appropriate available protocol/interface, and is dedicated for selection of new services, for example web pages, services, for example providing services with a correponding QoS, said first server means (I) thereby being considered as a signalling part of said arrangement.

3. Arrangement as claimed in claims 1 or 2 , c h a r a c t e r i z e d i n that a second of said server means (II) is running IP over a network system different from said first network system, for example ATM

(Asynchronous Transport Mode) , for thereby providing the requested services and correponding QoS (QoSl, ...QoSN) for said connected terminal or terminals, for example a client terminal (III) .

4. Arrangement as claimed in any of the preceding claims , c h a r a c t e r i z e d i n that said first server means (I) and said second QoS dedicated second server means (II) are configured in the same server or computer, said first and second server means (I, II) being given different IP addresses for thereby facilitating transfer of data therebetween.

5. Arrangement as claimed in any of the preceding claims, c h a r a c t e r i z e d i n that any terminal (III) connected to said server means (I, II) also has different IP addresses, for example related to a client terminal MAC card and a client terminal ATM card, respectively.

6. Arrangement as claimed in any of the preceding claims , c h a r a c t e r i z e d i n that said first server means (I) is a server connected to a data transmission system, for example the internet, and that said second server means (II) is a server connected to any or the same network providing selectively amendable respectively improved QoS, some dedicated server code being installed on said server means (I ,11), and that said connected terminal or terminals, possibly comprising a browser

(III) being configured so as to perform a signalling part by utilizing said transmission system, said terminal (III) and said first server (I) , for thereafter establishing connection providing amended QoS by utilizing the QoS dedicated server (II) , the network providing a modified QoS, as well as said terminal (III) .