(19)
(11)EP 1 429 497 B1

(12)EUROPEAN PATENT SPECIFICATION

(45)Mention of the grant of the patent:
02.03.2016 Bulletin 2016/09

(21)Application number: 02360339.2

(22)Date of filing:  09.12.2002
(51)Int. Cl.: 
H04L 12/715  (2013.01)

(54)

Method of relaying traffic from a source to a targeted destination in a communications network and corresponding equipment

Vorrichtung zum weiterleiten Verkehr von einem Ursprung zu einem Ziel in einem Kommunikationsnetz und entsprechende Ausrüstung

Procédé pour relayer un traffic d'une source vers une destination visée dans un réseau de communication et équipement correspondant


(84)Designated Contracting States:
AT BE BG CH CY CZ DE DK EE ES FI FR GB GR IE IT LI LU MC NL PT SE SI SK TR

(43)Date of publication of application:
16.06.2004 Bulletin 2004/25

(73)Proprietor: ALCATEL LUCENT
92100 Boulogne-Billancourt (FR)

(72)Inventors:
  • Van Ackere, Michel
    9100 Sint-Niklaas (BE)
  • Kennis, Paul
    2610 Wilrijk (BE)
  • Handekyn, Koen
    9000 Gent (BE)

(74)Representative: Kleinbub, Oliver 
Alcatel Lucent Intellectual Property & Standards Lorenzstrasse 10
70435 Stuttgart
70435 Stuttgart (DE)


(56)References cited: : 
US-A- 5 867 666
US-A- 5 903 545
  
  • CHOWDHURY A ET AL: "Dynamic Routing System (DRS): fault tolerance in network routing" COMPUTER NETWORKS, ELSEVIER SCIENCE PUBLISHERS B.V., AMSTERDAM, NL, vol. 31, no. 1-2, 14 January 1999 (1999-01-14), pages 89-99, XP004304478 ISSN: 1389-1286
  • AWEYA J: "On the design of IP routers Part 1: Router architectures" JOURNAL OF SYSTEMS ARCHITECTURE, ELSEVIER SCIENCE PUBLISHERS BV., AMSTERDAM, NL, vol. 46, no. 6, April 2000 (2000-04), pages 483-511, XP004190486 ISSN: 1383-7621
  
Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention).


Description


[0001] The present invention relates to a method of relaying traffic from a source to a targeted destination in a communications network, said method comprising the steps of:
  • providing a first and at least one second network adapter each providing access to a network having a plurality of destinations,
  • providing a first routing table which defines at least a first destination associated with the first network adapter,
  • providing at least one second routing table defining a second destination, which second destination is individually associated with said at least one second network adapter, and
  • relaying said traffic from the source to the targeted destination using one of the network adapters, wherein the step of relaying includes a step of selecting one of the first and second routing tables.


[0002] The invention further relates to hardware and software equipment which are configured to implement such a method in a communications network environment.

[0003] Such a method and the corresponding equipment are known from US 5,903,545.

[0004] In typical prior art systems, only one routing table is implemented in the machine. The routing table is some sort of a look-up table which is used by all network adapters in the decision process where an information packet has to be sent to next. The routing table typically comprises a plurality of line entries, each of which defining routing particulars for a certain destination or group of destinations. An example of a typical routing table, as it is used in prior art systems, is shown in Fig. 2 for illustrative purposes.

[0005] Each line entry typically comprises a destination address field and a mask field, the combination of which identifies a predefined destination or group of destinations. For each identified destination or group of destinations, a so-called next hop field and an interface field define where the information packets (the traffic) has to be relayed to. The next hop field defines the next intermediate destination on the way to the final targeted destination; the interface field defines the interface which is to be used on this route, for instance the network adapter to be used. Based on the entries in the routing table, the traffic is relayed along the route that provides the best match between the targeted destination and the predefined destinations identified in the destination and mask entries.

[0006] Typically, the routing table includes one default route which is chosen when no better match can be found among the specified destination entries (referred to as default situation in the following). If a plurality of destinations should be accessible along predefined routes and/or if for a specific destination different routes should be provided, a plurality of corresponding routing entries has to be included in the routing table. This applies particularly to cases, where different destinations should be reached simultaneously via different network adapters. However, the management of these entries becomes very complex when a network adapter is not statically configured for a specific destination or group of destinations. In addition, detailed knowledge about the network topology is required to establish an appropriate routing table in such a scenario.

[0007] Prior art reference US 5,903,545 mentioned initially discloses a method and an apparatus for responsive routing control in a communication system having a plurality of communication nodes. In a specific example, the plurality of communication nodes are satellites, and the traffic is relayed between selected ones from these satellites. Each satellite comprises a plurality of routing tables with one routing table for each communication port and with each communication port establishing a crosslink to another satellite. If a data packet to be relayed is received at one communication port, the corresponding routing table is used to determine to which port the data packet should be sent.

[0008] US 6,078,963 discloses a network router having a plurality of intelligent router ports. Each intelligent router port may have its own routing and/or forwarding engines. Thus, a centralized master routing and forwarding engine is not necessary. Each intelligent router port may have its own routing table.

[0009] In view of this background, it is an object of the present invention to provide a method and a corresponding equipment which allow to simplify the management and/or the administrative effort in configuring a machine which is set up to provide a plurality of network connections.

[0010] According to one aspect of the invention, this object is achieved by a method as mentioned at the outset, wherein the step of providing network adapters includes providing real network adapters and providing at least one virtual network adapter, wherein each virtual network adapter is individually associated with a third routing table, wherein the third routing table includes next hop and interface entries pointing to at least one of the following: another routing table or a real network adapter, and wherein the step of relaying uses the at least one virtual network adapter and its associated third routing table.

[0011] According to another aspect of the invention, this object is achieved by a network adapter for providing access to a network from a source, said network adapter comprising an individually associated routing table, wherein said network adapter is a virtual adapter, and said individually associated routing table comprises next hop and interface entries pointing to at least one of the following: another routing table or a real network adapter.

[0012] According to a further aspect of the invention, a client terminal and a router are provided, each comprising a plurality of network adapters of the afore-mentioned kind.

[0013] Moreover, a computer software product comprising an operating system component for connecting a source application running on a machine to a communications network is provided, the operating system component comprising a plurality of routing tables each configured to be individually associated with a network adapter of said machine, and further comprising a plurality of virtual network adapters, each virtual network adapter being associated, with one from a plurality of third routing tables and each associated third routing table comprising next hop and interface entries pointing to at least one of the following: another routing table or a real network adapter, wherein the source application dynamically selects a virtual network adapter for making a connection to the communications network.

[0014] The new method and the corresponding equipment provide the possibility to use a plurality of network adapters, each of which being associated with a default destination in a routing table at the same time. Therefore, a plurality of network adapters can be used without preferences assigned to one of them. In other worlds, each network adapter is now capable of providing access to a communications network via a route from a selected routing table. It is hence much easier to manage different routes involving a plurality of network adapters. In particular, it is no longer necessary to specify all the details and alternatives for those routes that are associated with a network adapter other than the default adapter in one routing table. Of course, it is still possible to define details of alternative routes within each of the plurality of routing tables. However, it is no longer necessary to do so in order to use the multiplicity of network adapters.

[0015] The management of the routing tables is particularly simplified in scenarios, where a plurality of source applications running on a machine want to access a plurality of destinations via different network adapters. Heretofore, only one network adapter could be used via a default route. For all other network adapters, the details of the routes had to be specifically included in the single routing table. Many backup or fallback positions had to be included in the single routing table in order to preserve all the routing possibilities, if the default route should be changed in a certain situation. The resulting complex management of the prior art routing tables is eliminated now, because it is basically sufficient to define one default route for each network adapter. A source application trying to connect to a network simply uses one of the routing tables and its corresponding network adapter (which is preferably triggered by the source application itself), and it is possible to relay the traffic along the default destination route for many adapters at the same time.

[0016] Introducing virtual network adapters even more increases the flexibility of managing the information flow to and from a source application, because it is possible now to define even more routing tables than real adapters are present in the machine.

[0017] Since the third routing table includes next hop and interface entries pointing to at least one of the following: another routing table or a real network adapter, the source application only needs to communicate with the virtual network adapter, which can be freely configured and adapted to different situations. The structure behind the virtual adapter is independent from the source application. The source applications are hence better shielded from intricacies on the connection level. Furthermore, an even more enhanced plurality of connection routes can be provided by defining different virtual adapters each having an associated routing table with a (default) destination route. The system configuration effort is particularly reduced in cases where a plurality of different networks is to be accessed by a plurality of source applications at the same time.

[0018] Another advantage of the new approach is that a detailed knowledge about the network topology is no longer needed for establishing several alternative routes for accessing one or more communications networks.

[0019] The above object is, therefore, completely achieved.

[0020] According to a preferred refinement, the first and second routing tables define said first and second destinations as default destinations which are used for traffic relay in any default situation.

[0021] Use of the concept of default destinations in a plurality of routing tables even more facilitates the management of a large number of routes via different network adapters. It goes without saying, however, that the routing table can additionally comprise specific destinations for establishing alternative routes, if desired.

[0022] In a further preferred refinement, at least some of the first and second routing tables comprise specific destinations pointing to another routing table.

[0023] As mentioned above, use of a plurality of routing tables does not render impossible to specify and use alternative routes defined within one or more of the plurality of routing tables. Implementing these specific destinations provides a quicker and easier "escape" route in cases where the default route does not work for what reason so ever. The amount of specific destinations in each routing table, and hence the amount of specific destinations in the routing tables at all, can nevertheless be greatly reduced compared to the prior art approach using only one routing table for a plurality of network adapters.

[0024] Following the preferred approach, an escape route can easily be defined by pointing to another routing table, thereby using the default route of the latter as a main choice for the escape route. Therefore, in a very consequent and easy implementation of the new approach, it is sufficient to define a default route in each routing table and a limited number of specific escape routes pointing to another routing table. No detailed knowledge about the network topologies is required for establishing these kinds of routing tables. The management effort is greatly reduced.

[0025] According to a further preferred refinement, the specific destination in the selected routing table(s) points to the escape routing table as a next hop entry.

[0026] This approach provides an easy but effective way to implement connections between the plurality of routing tables without the need of making considerable changes in the way that a routing table is used for determining a route for traffic relay. The next hop entries are commonly known and used as intermediate destinations in prior art systems. Establishing the (escape) referrals from one routing table to another in the next hop entries makes efficient use of existing system structures.

[0027] According to another preferred refinement, the step of selecting a routing table is triggered by the source.

[0028] This idea greatly increases flexibility and adaptability in using the different routes, because it is now under control of the source which route is selected. On the other hand, this flexibility is provided without the need of providing the source with a detailed knowledge about the network topology.

[0029] It goes without saying that the features described above and those yet to be explained below cannot be used in the disclosed combination only, but also in other combinations, as will be apparent to those skilled in the art. With respect to the following description, it is shown in:
Fig. 1
a simplified, schematic illustration of a client terminal connected to a plurality of communication networks according to one embodiment of the invention,
Fig. 2
a schematic illustration of a prior art method for relaying traffic in an environment similar to that as shown in Fig. 1,
Fig. 3
a schematic representation of a method using a plurality of routing tables, and
Fig. 4
a schematic representation of an embodiment of the invention.


[0030] In Fig. 1, reference numeral 10 designates an environment in which the present invention can be applied. The environment 10 comprises by way of non-limiting example a client terminal 12 and a plurality of isolated networks 14, 16, and 18. The client terminal 12 includes a plurality of network adapters 20, 22, and 24, each of which can be implemented either as hardware (e.g. as an Ethernet card adapter) or as software based on a hardware (e.g. as a PPPoE adapter). The network adapters 20, 22, 24 allow the client terminal 12 to access the networks 14, 16, 18, which is indicated by arrows 26, 28, 30 in Fig. 1. Thus, network adapters 20, 22, 24 are real network adapters in the sense of the present invention.

[0031] The networks 14, 16, 18 each comprise an access point 32, 34, 36, which might be a server or a router or any other suitable device allowing a connection from network adapters 20, 22, 24. A plurality of destinations 38, 40, 42 are connected to the access points 32, 34, 36, which destinations might be other servers, routers, client terminals or the like. Basically, the networks 14, 16, 18 may be any kind of communications networks that can be accessed from a client terminal 12.

[0032] With reference numeral 44, an operating system component is schematically illustrated. The operating system component 44 is part of the operating system running on client terminal 12, as it is basically known to those skilled in the art.

[0033] With reference numeral 46, a source application is schematically indicated. Source application 46 is running on the client terminal 12 using functionality that is provided by the operating system. By way of example, the source application 46 might be an internet browser, the client terminal 12 is a personal computer (PC) having the plurality of network adapters 20, 22, 24 implemented, and the operating system component comprises a functionality that implements the new method in a way described in further detail below.

[0034] The networks 14, 16, 18 might be isolated from each other, as is shown in Fig. 1 according to one embodiment of the invention. However, it is generally also feasible that the networks 14, 16, 18 are connected among each other, thereby defining an overall network having physical and/or logical sub-networks. It is also possible, that the networks 14, 16, 18 form part of an overall network without any differences, such that the client terminal 12 is actually connected to one integral network via different network adapters. By way of example, network 14 may be a network accessible via a high-speed connection for providing video-on-demand services. Network 16 may be the public switched telephone network (PSTN). Connection to network 16 is achieved then via a medium or low speed connection. Network 18 might be an intranet based on common LAN technology.

[0035] In Fig. 2, a prior art method for accessing networks 14, 16, 18 from a client terminal 12 is schematically shown. It is assumed that several applications run on the client terminal 12, which are distinguished here by reference numerals 46a, 46b, and 46c. Application 46a might be a program for displaying a video received from network 16, while application 46b is the internet browser already indicated above. 46c might designate any other application requiring access to one of the networks 14, 16, 18.

[0036] According to the prior art method, a single routing table 50 is used to establish connections between applications 46 and destinations 38, 40, 42 within the networks 14, 16, 18. The routing table 50 comprises a plurality of line entries 52, and each line entry 52 defines the details of a particular route for connection. The structure and use of routing tables 50 like this are sufficiently known to those skilled in the art.

[0037] As it is known to those skilled in the art, routing table 50 defines a default route (default destination), which is automatically chosen when no better match exists between the targeted destinations 38, 40, 42 and the specified destinations defined by specified address entries 52 in routing table 50 (default situation). Therefore, an information packet, which is to be sent from client terminal 12 to a targeted destination 38, 40, 42, is relayed to the default destination, unless a better match between the targeted destination address and one of the specific destination entries in routing table 50 can be found.

[0038] Since there is only one default route in routing table 50, only one of network adapters 20, 22, 24 can be associated therewith. For the remaining network adapters, specific destination entries have to be made in routing table 50. Moreover, it is often favorable to include specific destination entries for all the network adapters 20, 22, 24, in order to preserve all the connection information, if the default destination route is changed, which might occur, for instance, under control of applications 46. It is apparent that the management of line entries 52 in routing table 50 can become cumbersome, in particular in cases, where a plurality of applications simultaneously try to access a plurality of networks via different network adapters.

[0039] In the following description of preferred embodiments of the invention, like reference numerals designate elements already explained with respect to Figs. 1 and 2.

[0040] Fig. 3 shows a method employing a plurality of routing tables, with two routing tables 60, 62 shown here by way of example. Each routing table 60, 62 is individually associated with one of network adapters 20, 22, 24, and it preferably names the respective network adapter in the interface field of its corresponding default destination route. Therefore, each network adapter can be accessed from an application 46 as a default destination route by selecting the appropriate routing table 60, 62.

[0041] As shown, routing tables 60, 62 further include specific destination entries 64 which, in an even more preferred embodiment, each refer to another routing table in the next hop field. Thereby, it is easily possible to provide an escape route, if the targeted destination cannot be reached via the network adapter default route in the selected routing table. In Fig. 3, it is shown how applications 46 first chose routing table 60 for making a connection to one of networks 14, 16, 18. If the targeted destination lies within network 14, the default route defined in routing table 60 is appropriate and the connection is established via network adapter 20. However, if the targeted destination is in network 16, it cannot be reached via network adapter 20. As an escape route, the connection is relayed via routing table 62 by means of specific destination entry 64 referring to routing table 62 in the next hop field. Likewise, if another network is to be accessed, routing table 60 refers to yet another routing table (not shown here for sake of simplicity), as it is indicated by arrow 66.

[0042] Fig. 3 shows a situation, where all applications 46 firstly use routing table 60, which might be defined as a default routing table in the operating system underlying applications 46. In another implementation, however, applications 46 individually select an appropriate routing table, for instance by displaying a selection field to the user, if appropriate. Additionally, appropriate selection of the most suitable routing table might be configured by a user in profile definitions, as it is already known in the art.

[0043] In the embodiment shown in Fig. 4, the concept of using a plurality of routing tables is still maintained. Additionally, however, virtual network adapters 70, 72 having associated routing tables 74, 76 are introduced. In the preferred embodiment shown in Fig. 4, applications 46 dynamically select a virtual adapter 70, 72 for making a connection to one of networks 14, 16, 18. By means of associated routing tables 74, 76, the virtual adapters 74, 76 then refer to an appropriate routing table 60, 62 associated with one of real network adapters 20, 22, 24. Alternatively, the routing tables 74, 76 of the selected virtual adapter might also directly refer to a real adapter, as it is shown by means of virtual adapter 74 and real adapter 24.

[0044] By introducing the concept of virtual adapters 70, 72, preferably all the communication is routed via the virtual adapters.

[0045] The routing tables 74, 76 associated with each virtual adapter 70, 72 refer in the next hop and interface fields either to other routing tables 60, 62 associated with a specific real adapter 20, 22 or to the real adapters 20, 22 themselves. In other words, the complete traffic is mediated then using the virtual adapters routing tables 74, 76. If a group of applications 46 wants to use the same real adapters for reaching a targeted destination, they can chose the same virtual adapter. However, applications that want to use different real adapters for reaching the same destinations simply chose different virtual adapters. This concept provides an increased flexibility in establishing network connections, while it still keeps the management effort low due to the possibility of using default destination entries for making the connections.


Claims

1. A method of relaying traffic from a source (46) to a targeted destination (40) in a communications network (14, 16, 18), said method comprising the steps of:

- providing a first (20) and at least one second (22, 24) network adapter each providing access to a network (14, 16, 18) having a plurality of destinations (38, 40, 42),

- providing a first routing table (60) which defines at least a first destination associated with the first network adapter (20),

- providing at least one second routing table (62) defining a second destination, which second destination is individually associated with said at least one second network adapter (24),

- relaying said traffic from the source (46) to the targeted destination (40) using one of the network adapters (20, 22, 24), and wherein the step of relaying includes a step of selecting one of the first and second routing tables (60, 62),

characterized in that the step of providing network adapters includes providing real network adapters (20, 22, 24) and providing at least one virtual network adapter (70, 72), wherein each virtual network adapter (70, 72) is individually associated with a third routing table (74, 76), wherein the third routing table (74, 76) includes next hop and interface entries pointing to at least one of the following: another routing table (60, 62) or a real network adapter (20, 22, 24), and wherein the step of relaying uses the at least one virtual network adapter (70, 72) and its associated third routing table (74, 76).
 
2. The method of claim 1, wherein at least some of the first and second routing tables (60) comprise specific destinations pointing to another routing table (62), preferably by means of a next hop entry.
 
3. The method of claim 1, wherein the first and second routing tables (60, 62) define said first and second destinations as default destinations which are used for traffic relay in any default situation.
 
4. The method of claim 1, wherein the step of selecting a routing table (60, 62; 74, 76) is triggered by the source (46).
 
5. A network adapter for providing access to a network (14, 16, 18) for relaying traffic from a source (46) to a targeted destination (40), said adapter comprising an individually associated routing table (60, 62, 74, 76), characterized by being a virtual adapter, said individually associated routing table (74, 76) comprising next hop and interface entries pointing to at least one of the following: another routing table (60, 62) or a real network adapter (20, 22, 24).
 
6. A client terminal comprising a plurality of network adapters (20, 22, 24, 70, 72) for providing access to a network (14, 16, 18) and comprising a plurality of routing tables (60, 62, 74 76), wherein each network adapter (20, 22, 24, 70, 72)) is individually associated with one from the plurality of routing tables (60, 62, 74, 76), characterized in that the plurality of network adapters comprises at least one virtual network adapter (70, 72) having an associated routing table (74, 76) comprising next hop and interface entries pointing to at least one of the following: another routing table (60, 62) or a real network adapter (20, 22, 24).
 
7. A router for relaying traffic from a source (46) to a targeted destination (38, 40, 42) in a communications network (14, 16, 18), comprising a plurality of network adapters (20, 22, 24, 70, 72) for providing access to the network (14, 16, 18), and a plurality of routing tables (60, 62, 74, 76), wherein each network adapter (20, 22, 24, 70, 72) is individually associated with one from the plurality of routing tables (60, 62, 74, 76), characterized in that the plurality of network adapters comprises at least one virtual network adapter (70, 72) having an associated routing table (74, 76) comprising next hop and interface entries pointing to at least one of the following: another routing table (60, 62) or a real network adapter (20, 22, 24).
 
8. A computer software product comprising an operating system component for connecting a source application (46) running on a machine (12) to a communications network (14, 16, 18), the operating system component comprising a plurality of routing tables (60, 62) each configured to be individually associated with a network adapter (20, 22, 24) of said machine (12), characterized by a plurality of virtual network adapters (70, 72), each virtual network adapter (70, 72) being associated with one from a plurality of third routing tables (74, 76) and each associated third routing table (74, 76) comprising next hop and interface entries pointing to at least one of the following: another routing table (60, 62) or a real network adapter (20, 22, 24), wherein the source application (46) dynamically selects a virtual network adapter (70, 72) for making a connection to the communications network (14, 16, 18).
 


Ansprüche

1. Verfahren für das Weiterleiten von Verkehr von einem Ursprung (46) zu einem angesteuerten Ziel (40) in einem Kommunikationsnetz (14, 16, 18), wobei besagtes Verfahren die folgenden Schritte umfasst:

- Bereitstellen eines ersten (20) und mindestens eines zweiten (22, 24) Netzadapters, von denen jeder Zugang zu einem Netz (14, 16, 18) gibt und wobei eine Vielzahl von Zielen (38, 40, 42) gegeben ist,

- Bereitstellen einer ersten Routingtabelle (60), welche mindestens ein erstes Ziel definiert, das dem ersten Netzadapter (20) zugeordnet ist,

- Bereitstellen mindestens einer zweiten Routingtabelle (62), welche ein zweites Ziel definiert, wobei besagtes zweites Ziel individuell besagtem mindestens einen zweiten Netzadapter (24) zugeordnet ist,

- Weiterleiten besagten Verkehrs vom Ursprung (46) zum angesteuerten Ziel (40) unter Verwendung einen der Netzadapter (20, 22, 24) und wobei der Schritt des Weiterleitens einen Schritt des Auswählens einer von beiden, der ersten oder der zweiten Routingtabelle (60, 62) umfasst,

dadurch gekennzeichnet, dass der Schritt der Bereitstellung von Netzadaptern das Bereitstellen von realen Netzadaptern (20, 22, 24) und das Bereitstellen von mindestens einem virtuellen Netzadapter (70, 72) umfasst, wobei jeder virtuelle Netzadapter (70, 72) individuell einer dritten Routingtabelle (74, 76) zugeordnet ist, wobei die dritte Routingtabelle (74, 76) Next-Hop- und Schnittstelleneinträge umfasst, die zumindest eines der folgenden beiden Elemente ansteuern, nämlich eine weitere Routingtabelle (60, 62) oder einen realen Netzadapter (20, 22, 24), und wobei der Schritt des Weiterleitens den mindestens einen virtuellen Netzadapter (70, 72) und die diesem zugeordnete Routingtabelle (74, 76) benutzt.
 
2. Verfahren nach Anspruch 1, wobei mindestens einige der ersten und der zweiten Routingtabellen (60) spezifische Ziele enthalten, die auf eine andere Routingtabelle (62) verweisen, vorzugsweise anhand eines Next-Hop-Eintrags.
 
3. Verfahren nach Anspruch 1, wobei die ersten und die zweiten Routingtabellen (60, 62) die besagten ersten und zweiten Ziele als voreingestellte Ziele definieren, welche für die Verkehrsweiterleitung in jedweder voreingestellten Situation verwendet werden.
 
4. Verfahren nach Anspruch 1, wobei der Schritt des Auswählens einer Routingtabelle (60, 62; 74, 76) vom Ursprung (46) ausgelöst wird.
 
5. Netzadapter für das Gewähren von Zugang zu einem Netz (14, 16, 18) für das Weiterleiten von Verkehr von einem Ursprung (46) zu einem angesteuerten Ziel (40), wobei besagter Adapter eine individuell zugeordnete Routingtabelle (60, 62, 74, 76) umfasst, dadurch gekennzeichnet, dass es sich um einen virtuellen Adapter handelt, wobei besagte, individuell zugeordnete Routingtabelle (74, 76) Next-Hop- und Schnittstellen-Einträge umfasst, die auf mindestens eines der folgenden Elemente verweisen, nämlich eine weitere Routingtabelle (60, 62) oder einen realen Netzadapter (20, 22, 24).
 
6. Kundenendgerät, eine Vielzahl von Netzadaptern (20, 22, 24, 70, 72) für das Gewähren von Zugang zu einem Netz (14, 16, 18) und eine Vielzahl von Routingtabellen (60, 62, 74, 76) umfassend, wobei jeder Netzadapter (20, 22, 24, 70, 72) individuell einer aus der Vielzahl von Routingtabellen (60, 62, 74, 76) zugeordnet ist, dadurch gekennzeichnet, dass die Vielzahl der Netzadapter mindestens einen virtuellen Netzadapter (70, 72) umfasst, dem eine Routingtabelle (74, 76) zugeordnet ist, die Next-Hop- und Schnittstellen-Einträge umfasst, die auf mindestens eines der folgenden Elemente verweisen, nämlich eine Routingtabelle (60, 62) oder einen realen Netzadapter (20, 22, 24).
 
7. Router für das Weiterleiten von Verkehr von einem Ursprung (46) zu einem angesteuerten Ziel (38, 40, 42) in einem Kommunikationsnetz (14, 16, 18), eine Vielzahl von Netzadaptern (20, 22, 24, 70, 72) für das Gewähren von Zugang zu dem Netz (14, 16, 18) und eine Vielzahl von Routingtabellen (60, 62, 74, 76) umfassend, wobei jeder Netzadapter (20, 22, 24, 70, 72) individuell einer aus der Vielzahl von Routingtabellen (60, 62, 74, 76) zugeordnet ist, dadurch gekennzeichnet, dass die Vielzahl der Netzadapter mindestens einen virtuellen Netzadapter (70, 72) umfasst, dem eine Routingtabelle (74, 76) zugeordnet ist, die Next-Hop- und Schnittstellen-Einträge umfasst, die auf mindestens eines der folgenden Elemente verweisen, nämlich eine Routingtabelle (60, 62) oder einen realen Netzadapter (20, 22, 24).
 
8. Ein eine Betriebssystemkomponente für das Anbinden einer Ursprungsanwendung (46) umfassendes Computersoftwareprodukt, das auf einer zu einem Kommunikationsnetz (14, 16, 18) gehörenden Ausrüstung (12) läuft, wobei die Betriebssystemkomponente eine Vielzahl von Routingtabellen (60, 62) umfasst, jede von ihnen dafür konfiguriert, individuell einem Netzadapter (20, 22, 24) besagter Ausrüstung (12) zugeordnet zu sein, gekennzeichnet durch eine Vielzahl virtueller Netzadapter (70, 72), wobei jeder virtuelle Netzadapter (70, 72) einer aus der Vielzahl dritter Routingtabellen (74, 76) zugeordnet ist und wobei jede zugeordnete dritte Routingtabelle (74, 76) Next-Hop- und Schnittstelleneinträge für mindestens eines der folgenden Elemente umfasst, nämlich eine weitere Routingtabelle (60, 62) oder einen realen Netzadapter (20, 22, 24), wobei die Ursprungsanwendung (46) dynamisch einen virtuellen Netzadapter (70, 72) auswählt, um eine Verbindung zum Kommunikationsnetz (14, 16, 18) herzustellen.
 


Revendications

1. Procédé pour relayer un trafic à partir d'une source (46) vers une destination ciblée (40) dans un réseau de communication (14, 16, 18), ledit procédé comprenant les étapes suivantes :

- fournir un premier adaptateur de réseau (20) et au moins un deuxième adaptateur de réseau (22, 24) fournissant chacun un accès à un réseau (14, 16, 18) ayant une pluralité de destinations (38, 40, 42),

- fournir une première table de routage (60) qui définit au moins une première destination associée au premier adaptateur de réseau (20),

- fournir au moins une deuxième table de routage (62) définissant une deuxième destination, laquelle deuxième destination étant associée individuellement audit au moins un deuxième adaptateur de réseau (24),

- relayer ledit trafic à partir de la source (46) vers la destination ciblée (40) en utilisant un des adaptateurs de réseau (20, 22, 24), et dans lequel l'étape de relais comprend une étape de sélection d'une des première et deuxième tables de routage (60, 62),

caractérisé en ce que l'étape de fourniture d'adaptateurs de réseau comprend la fourniture d'adaptateurs de réseau réels (20, 22, 24) et la fourniture d'au moins un adaptateur de réseau virtuel (70, 72), dans lequel, chaque adaptateur de réseau virtuel (70, 72) est associé individuellement à une troisième table de routage (74, 76), dans lequel la troisième table de routage (74, 76) comprend des entrées de saut suivant et d'interface indiquant au moins un des éléments suivants : un autre table de routage (60, 62) ou un adaptateur de réseau réel (20, 22, 24), et dans lequel l'étape de relais utilise l'au moins un adaptateur de réseau virtuel (70, 72) et sa troisième table de routage associée (74, 76).
 
2. Procédé selon la revendication 1, dans lequel au moins certaines des première et deuxième tables de routage (60) comprennent des destinations spécifiques indiquant une autre table de routage (62), de préférence au moyen d'une entrée de saut suivant.
 
3. Procédé selon la revendication 1, dans lequel la première et la deuxième tables de routage (60, 62) définissent lesdites première et deuxième destinations comme des destinations par défaut qui sont utilisées pour le relais de trafic dans n'importe quelle situation par défaut.
 
4. Procédé selon la revendication 1, dans lequel l'étape de sélection d'une table de routage (60, 62, 74, 76) est déclenchée par la source (46).
 
5. Adaptateur de réseau pour fournir l'accès à un réseau (14, 16, 18) pour relayer un trafic à partir d'une source (46) vers une destination ciblée (40), ledit adaptateur comprenant une table de routage associée individuellement (60, 62, 74, 76), caractérisé en ce qu'il s'agit d'un adaptateur virtuel, ladite table de routage associée individuellement (74, 76) comprenant des entrées de saut suivant et d'interface indiquant au moins un des éléments suivants : une autre table de routage (60, 62) ou un adaptateur de réseau réel (20, 22, 24).
 
6. Terminal client comprenant une pluralité d'adaptateurs de réseau (20, 22, 24, 70, 72) pour fournir l'accès à un réseau (14, 16, 18) et comprenant une pluralité de tables de routage (60, 62, 74, 76), dans lequel chaque adaptateur de réseau (20, 22, 24, 70, 72) est associé individuellement à une table parmi la pluralité de tables de routage (60, 62, 74, 76), caractérisé en ce que la pluralité d'adaptateurs de réseau comprend au moins un adaptateur de réseau virtuel (70, 72) ayant une table de routage associée (74, 76) comprenant des entrées de saut suivant et d'interface indiquant au moins un des éléments suivants : une autre table de routage (60, 62) ou un adaptateur de réseau réel (20, 22, 24).
 
7. Routeur pour relayer un trafic à partir d'une source (46) vers une destination ciblée (38, 40, 42) dans un réseau de communication (14, 16, 18), comprenant une pluralité d'adaptateurs de réseau (20, 22, 24, 70, 72) pour fournir l'accès au réseau (14, 16, 18), et une pluralité de tables de routage (60, 62, 74, 76), dans lequel chaque adaptateur de réseau (20, 22, 24, 70, 72) est associé individuellement à une table parmi la pluralité de tables de routage (60, 62, 74, 76), caractérisé en ce que la pluralité d'adaptateurs de réseau comprend au moins un adaptateur de réseau virtuel (70, 72) ayant une table de routage associée (74, 76) comprenant des entrées de saut suivant et d'interface indiquant au moins un des éléments suivants : une autre table de routage (60, 62) ou un adaptateur de réseau réel (20, 22, 24).
 
8. Produit logiciel informatique comprenant un élément de système d'exploitation pour connecter une application source (46) exécutée sur une machine (12) à un réseau de communication (14, 16, 18), l'élément de système d'exploitation comprenant une pluralité de tables de routage (60, 62) chacune étant configurée pour être associée individuellement à un adaptateur de réseau (20, 22, 24) de ladite machine (12), caractérisé par une pluralité d'adaptateurs de réseau virtuel (70, 72), chaque adaptateur de réseau virtuel (70, 72) étant associé à une table parmi une pluralité de troisièmes tables de routage (74, 76) et chaque troisième table de routage associée (74, 76) comprenant des entrées de saut suivant et d'interface indiquant au moins un des éléments suivants : une autre table de routage (60, 62) ou un adaptateur de réseau réel (20, 22, 24), dans lequel l'application source (46) sélectionne dynamiquement un adaptateur de réseau virtuel (70, 72) pour réaliser une connexion avec le réseau de communication (14, 16, 18).
 




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REFERENCES CITED IN THE DESCRIPTION



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Patent documents cited in the description