WO2004089002A1

WO2004089002A1 - Telecommunication network for transmitting signalling messages

Info

Publication number: WO2004089002A1
Application number: PCT/EP2003/003297
Authority: WO
Inventors: Dominikus Herzberg; Jörg Bruss
Original assignee: Telefonaktiebolaget Lm Ericsson (Publ)
Priority date: 2003-03-29
Filing date: 2003-03-29
Publication date: 2004-10-14
Also published as: AU2003219115A1

Abstract

The invention relates to a telecommunication network for transmitting signalling messages between a first protocol instance (MUPI3) and a second protocol instance (MUPI4) of a message transfer part 3 user protocol in a domain of the telecommunication network in that signalling messages are transmitted according to a connectionless transport protocol. The protocol instances are addressed using transport addresses. Each of the first and the second protocol instance (MUPI3; MUPI4) is connected to the connectionless transport protocol via an adaptor (A1; A2; A). The adaptor (A1; A2; A) provides a conversion from a message transfer part 3 user address comprising at least one of a signalling point code, a network indicator and a service indicator to a transport address used for addressing the respective protocol instance and vice versa.

Description

Telecommunication network for transmitting signalling messages

Field of invention

The invention relates to a telecommunication network for transmitting signalling messages between protocol instances of a message transfer part 3 user protocol.

Description of prior art

Network nodes in fixed and mobile telecommunication networks are connected by signalling networks for transmitting signalling messages such as messages for setting up calls, messages for querying databases in a telecommunication network or network management messages. A standard for signalling messages that has found a wide dissemination is the SS7 (signalling system number 7) standard comprising the MTP (message transfer part) protocol stack and MTP 3 user protocols. Examples for MTP 3 user protocols are the TUP (Telephone User Part protocol) protocol, the ISUP (Integrated Services Digital Network User Part) protocol or the SCCP (Signalling Connection Control Part) protocol.

Currently many network operators are planning to use IP networks for transmission of MTP3 user signalling messages. Furthermore network operators want to interconnect such an IP network and an existing MTP signalling network. According to the state of the art M3UA (MTP3 user adaptation layer) is used as a protocol between the MTP3 user protocol and the SCTP (stream control transmission protocol) as the transport protocol above the IP (internet protocol). Signalling gateways are installed as intermediate nodes between an MTP domain in a signalling network and an IP domain in a signalling network. M3UA is described in the RFC (Request For Comments) 3332 of the IETF (Internet Engineering Task Force).

In an IP domain using the M3UA protocol connections are terminated by the signalling gateways mediating between the MTP domain and the IP domain. Addresses of signalling gateways must therefore be administrated at each SEP (signalling end point) in the IP domain creating large administration costs. Another drawback of the M3UA protocol is the difference of handling connections to within the IP domain and connections between the IP domain and the MTP domain. Protocol instances of an MTP3 user protocol in the IP domain are connected to different protocol instances using different connections complying with the M3UA protocol. In contrast to that the protocol instances of an MTP3 user protocol in the IP domain are connected to different protocol instances of an MTP3 user protocol in the MTP domain using only one connection to the signalling gateway. Therefore a differentiation has to be made between connections towards single protocol instances of the MTP3 user protocol and connections towards a plurality of protocol instances of the MTP3 user protocol, thus creating further administration costs.

Furthermore the introduction of the M3UA layer as a further protocol layer is processing power consuming in the network nodes on which protocol instances of the M3UA protocol are installed.

Therefore it is object of the invention to overcome the shortcomings of the state of the art and provide a simple and cost- effective method for transmitting signalling messages among protocol instances of a message transfer part 3 user protocol in a internet protocol domain of a telecommunication network and between protocol instances in a internet protocol domain and protocol instances in an MTP domain of the telecommunication network.

Summary of the invention

This object is achieved by the telecommunication network of claim 1, the adaptor of claim 4, and the signalling gateway of claim 8. Advantageous embodiments can be derived from the dependent claims.

According to the present invention a telecommunication network is adapted to transmit signalling messages between a first protocol instance and a second protocol instance of a message transfer part 3 user protocol in a first domain of the telecommunication network. In this first domain signalling messages between the protocol instances of the message transfer part 3 user protocol are transmitted according to a connectionless transport protocol and the protocol instances are addressed using transport addresses. A transport address comprises for example an IP address, a protocol identifier of the connectionless transport protocol and a source port or a destination port. Each of the first and the second protocol instance are connected to the connectionless transport protocol via an adaptor. The adaptor provides a conversion from a message transfer part 3 user address comprising at least one of a signalling point code, a network indicator and a service indicator to a transport address used for addressing the respective protocol instance and vice versa.

In an advantageous embodiment of the invention the telecommunication network also comprises a third protocol instance of the message transfer part 3 user protocol in a second domain of the telecommunication network. In said second domain signalling messages between the protocol instances are transmitted according to a message transfer part 3 protocol and the protocol instances are addressed using a message transfer part 3 user address comprising at least one of a signalling point code, a network indicator and a service indicator. The first protocol instance is addressable from the second domain using a message transfer part 3 user address. The third protocol instance is addressable from the first domain using a transport address. The telecommunication network comprises a signalling gateway connecting the first and the second domain. The signalling gateway provides a conversion from a message transfer part 3 user address used for addressing a protocol instance to a transport address used for addressing said protocol instance and vice versa. The signalling gateway is adapted to receive a signalling message transmitted according to the transmission protocol of one of the domains and to send said signalling message according to the transmission protocol of the respective other domain. Furthermore the telecommunication network comprises means for differentiating according to a destination address of a signalling message between a signalling message destined to a protocol instance in the first domain and a signalling message destined to a protocol instance in the second domain. The telecommunication network comprises routing means for routing a signalling message towards the first or the second domain according to the result of said differentiation.

It is an advantage of the telecommunication network according to the invention, that in a signalling message transmitted by a protocol instance in the first domain, transport addresses can be used for addressing both, protocol instances in the first domain and protocol instances in the second domain of the telecommunication network. Accordingly, in a signalling message transmitted by a protocol instance in the second domain message transfer part 3 user addresses can be used for addressing both protocol instances in the first domain and protocol instances in the second domain of the telecommunication network. Thus protocol instances in the first and in the second domain do not need to know the domain the addressed protocol instance belongs to. Furthermore protocol instances do not need to know the network address of the signalling gateway via which the signalling message must be transmitted, thus limiting the effort for administration of the telecommunication network.

In a preferred embodiment of the invention the telecommunication network is adapted to transmit signalling messages according to different kinds of message transfer part 3 user protocols. To this end in the first domain a signalling message comprises an indication of the message transfer part 3 user protocol the signalling message complies with. The adaptor connecting the first or the second protocol instance to the connectionless transport protocol and the signalling gateway provide a conversion from the indication of the message transfer part 3 user protocol to a service indicator identifying the message transfer part 3 user protocol and vice versa.

Providing transmission of signalling messages of different kinds of message transfer part 3 user protocols is advantageous as it allows connecting of protocol instances of different kinds to one telecommunication network. An adaptor according to the invention connects a protocol instance of a message transfer part 3 user protocol to a connectionless transport protocol. To this end the adaptor provides a conversion from a message transfer part 3 user address used for addressing a protocol instance, to a transport address used for addressing assigned to said protocol instance and vice versa. The message transfer part 3 user address comprises at least one of a signalling point code, a network indicator and a service indicator.

In an embodiment of the invention the adaptor provides a conversion from a service indicator identifying the message transfer part 3 user protocol to an indication of the message transfer part 3 user protocol transmitted in a packet according to the connectionless transport protocol and vice versa. This provides the possibility to connect protocol instances of message transfer part 3 protocols of different kinds to the connectionless transport protocol.

In a further advantageous embodiment of the invention an adaptor provides a conversion from a status indication of the first domain of the telecommunication network to a network management primitive according to the message transfer part 3 protocol and vice versa. This provides the possibility to jointly manage the first and the second domain of the telecommunication network.

The connectionless internet protocol user transport protocol can be e.g. a User Datagram Protocol.

A Signalling gateway according to the present invention connects the first and the second domain of a telecommunication network. The signalling gateway provides a conversion from a message transfer part user address used for addressing a protocol instance to a transport address used for addressing said protocol instance and vice versa. The signalling gateway is adapted to receive a signalling message transmitted according to the transmission protocol of one of the domains and to send said signalling message according to the transmission protocol of the respective other domain. In a preferred embodiment the signalling gateway is capable of transmitting signalling messages according to different kinds of message transfer part protocols. In this embodiment in the first domain a signalling message transmitted according to the connectionless transport protocol comprises an indication of the message transfer part 3 user protocol the signalling message complies with and the signalling gateway provides a conversion from the indication of the message transfer part 3 user protocol to a service indicator identifying the message transfer part 3 user protocol and vice versa.

Providing transmission of signalling messages of different kinds of message transfer part protocols is advantageous as it allows connecting of protocol instances of different kinds to one telecommunication network.

In a preferred embodiment of the invention the signalling gateway is adapted to perform a conversion from a status indication of the first domain of the telecommunication network to a network management primitive according to the message transfer part 3 protocol and vice versa.

This provides the possibility to jointly manage the first and the second domain of the telecommunication network.

Brief description of the drawings

The following figures show:

Fig. 1 : depicts a telecommunication network connecting protocol instances of a message transfer part 3 user protocol in an MTP (Message Transfer Part) domain of the telecommunication network and protocol instances of the message transfer part 3 user protocol in an IP (internet protocol) domain of the telecommunication network.

Fig. 2: depicts a signalling gateway for connecting an MTP domain and an IP domain of a telecommunication network. Fig. 3 depicts an adaptor for connecting protocol instances of the message transfer part 3 user protocol to an IP (internet protocol).

Fig.4 depicts a mapping between protocol fields of an IP packet transmitting a signalling message according to an MTP3 (message transfer part 3) user protocol and protocol fields of an MTP3 packet transmitting said message.

Detailed description of embodiments

In the following the invention is described in more detail by means of embodiments and figures. Equal reference signs indicate equal elements.

Figure 1 depicts a telecommunication network according to the invention. The telecommunication network comprises an IP (internet protocol) domain and an MTP domain. The MTP domain of the telecommunication network comprises protocol instances of an MTP 3 user protocol that shall be termed a third and a fourth MTP3 (message transfer part 3) user protocol instance, MUPIl and MUPI2. MTP3 user signalling messages can be transmitted from and towards the third and the fourth MTP3 user protocol instance, MUPIl and MUPI2. Examples for MTP3 user protocols are the TUP (Telephone User Part protocol) protocol, the ISUP (Integrated Services Digital Network User Part) protocol or the SCCP (Signalling Connection Control Part) protocol. The third MTP3 user protocol instance MUPIl is connected to the MTP network MTPN via a first MTP3 protocol instance MPI1. The third MTP3 user protocol instance MUPIl is addressable using a first message transfer part 3 user address, wherein the first message transfer part 3 user address comprises a first signalling point code SPC1 that is assigned the third MTP3 protocol instance MPI1 and a first service SI indicator that indicates the kind of MTP3 user protocol of the third MTP3 user protocol instance MUPIl. Furthermore the first message transfer part 3 user address comprises a network indication of the MTP network MTPN. Accordingly the fourth MTP3 user protocol instance MUPI2 is connected to the MTP network MTPN via a second MTP3 protocol instance MPI2. The fourth MTP3 user protocol instance MUPI2 is addressable using a second message transfer part 3 user address, wherein the second message transfer part 3 user address comprises a second signalling point code SPC2 that is assigned to the second MTP3 protocol instance MPI2 and a second service indicator SI2 that indicates the kind of MTP3 user protocol of the fourth MTP3 user protocol instance MUPI2. Furthermore the second message transfer part 3 user address comprises a network indication of the MTP network MTPN. If the third and the fourth MTP3 user protocol instance MUPIl and MUPI2 relate to the same kind of MTP3 user protocol, the first and the second service indicator SI1 and SI2 are identical. The first and the second MTP3 protocol instance, MPI1 and MPI2 are interconnected by the MTP network MTPN and are connected to the signalling gateway SG by the MTP network MTPN.

The IP domain of the telecommunication network comprises a first and a second MTP3 user protocol instance, MUPI3 and MUPI4. In the IP domain signalling messages between the MTP3 user protocol instances are transmitted according to a connectionless transport protocol. In the IP domain of the telecommunication network the first MTP3 user protocol instance MUPI3 is connected to an IP network IPN via a first IP protocol instance IPPI1, a first protocol instance of the connectionless transport protocol CTPI1 and a first adaptor Al. The first MTP3 user protocol instance MUP13 is addressable using a first transport address. The first transport address comprises a first IP address IP1, that is assigned to the first IP protocol instance JPPI1, a protocol identifier of the connectionless transport protocol and a source port or a destination port.

Accordingly in the IP domain of the telecommunication network the second MTP3 user protocol instance MUPI4 is connected to an DP network IPN via a second IP protocol instance IPPI2, a protocol instance of the connectionless transport protocol CTPI2 and a second adaptor A2. The second MTP3 user protocol instance MUPI4 is addressable using a second transport address. The second transport address comprises a second IP address IP2, that is assigned to the second IP protocol instance IPPI2, a protocol identifier of the connectionless transport protocol and a source port or a destination port. The IP domain and the MTP domain of the telecommunication network are interconnected by the signalling gateway SG. The signalling gateway SG is adapted to receive and send signalling messages transmitted between the protocol instances of the message transfer part 3 user protocol. Particularly the signalling gateway is adapted to receive said signalling messages transmitted according to the transmission protocol of one of the domains and send said signalling message according to the transmission protocol of the respective other domain. I.e. the signalling gateway is adapted to receive a signalling message transmitted according the message transfer part 3 protocol and to send said signalling message according to the connectionless transport protocol and the signalling gateway is adapted to receive a signalling message transmitted according to the connectionless transport protocol and send said signalling message according to the message transfer part protocol.

The signalling gateway provides a conversion from a message transfer part 3 user address assigned to a protocol instance wherein the message transfer part 3 user address comprises a signalling point code, a network indicator and a service indicator to a transport address assigned to said protocol instance and vice versa. In that particular embodiment the conversion includes a conversion from an IP address to a signalling point code, wherein the signalling point code is used for addressing an MTP3 user protocol instance in the MTP domain and the IP address is used for addressing an MTP3 user protocol instance in the IP domain. To this end the signalling gateway SG comprises a mapping table MT providing a mapping between signalling point codes and internet protocol addresses used for addressing the protocol instances of an MTP3 user protocol.

The first signalling point code SPC1 used for addressing the third MTP3 user protocol instance MUPIl in the MTP domain is mapped to a third IP address IP3 used for addressing said third MTP3 user protocol instance MUPIl from the IP domain and vice versa. The second signalling point code SPC2 used for addressing the fourth MTP3 user protocol instance in the MTP domain is mapped to a fourth IP address IP4 used for addressing said fourth MTP3 user protocol instance MUPI2 from the IP domain and vice versa. The first IP address IP1 used for addressing the first MTP3 user protocol instance in the IP domain is mapped to the third signalling point code SPC3 used for addressing said first MTP3 user protocol instance MUPI3 from the MTP domain and vice versa. The second IP address IP2 used for addressing the second MTP3 user protocol instance MUPI4 in the IP domain is mapped to the fourth signalling point code SPC4 used for addressing said second MTP3 user protocol instance MUPI4 from the MTP domain and vice versa.

In the following a message from the MTP domain to the IP domain is shown by example of an MTP3 user signalling message sent from the third MTP3 user protocol instance MUPIl to the first MTP3 user protocol instance MUPI3. That signalling message comprises the first signalling point code SPCl as OPC (originating point code), the third signalling point code SPC3 as DPC (destination point code), and an SI1 (service indicator) that indicates the kind of MTP3 user protocol. The signalling message is transmitted in the MTP domain from the third MTP3 protocol instance MPI1 to the signalling gateway SG as message according to the MTP3 protocol. The signalling gateway receives the signalling message transmitted according to the message transfer part 3 protocol and sends said signalling message according to the connectionless transport protocol towards the first MTP3 user protocol instance MUPI3. Via the mapping table MT the first signalling point code SPCl that has been used as OPC is converted into the third IP address IP3 to be used as source IP address in one or more D? packets transmitting the MTP3 user signalling message. Accordingly the third signalling point code SPC3 that has been used as DPC (destination point code) is converted into the first IP address IP1 to be used as destination IP address of the one or more IP packets transmitting the MTP3 user signalling message. The service indicator of the signalling message is converted into an indication of the kind of MTP3 user protocol that is encoded in the one or more IP packets, e.g. as destination port or in the payload of an IP packet.

The one or more IP packets transmitting the signalling message are transmitted to the first IP protocol instance IPPIl . From there the signalling message is handed over via the first protocol instance of the connectionless transport protocol CTP1 and the first adaptor Al to the first MTP3 user protocol instance MUPI3. The kind of message transfer part 3 user protocol can be determined by the first adaptor Al according to the destination port or according to the indication of the kind of MTP3 protocol that has been encoded in the payload of the IP packet. The first adaptor Al converts the first IP address DPI that has been used as destination IP address to the third signalling point code SPC3 as DPC and the third D? address IP3 that has been used as source IP address to the first signalling point code SPCl as OPC.

The transmission of a message from the IP domain to the MTP domain is shown by example of an MTP3 user signalling message sent from the second MTP3 user protocol instance MUPI4 to the fourth MTP3 user protocol instance MUPI2. In this signalling message the fourth signalling point code SPC4 is used as OPC and the second signalling point code SPC2 is used as DPC. The MTP3 user signalling message is conveyed in one or more IP packets by the second connectionless transport protocol instance CTPI2. The second adaptor A2 performs a conversion from the fourth signalling point code SPC4 to the second IP address B?2 and from the second signalling point code SPC2 to the fourth IP address D?4. In the IP packets transmitting. he MTP3 user signalling message, the fourth IP address 1P4 is used as destination IP address- and the second IP address IP2 is used as source D? address. The kind of MTP3 user protocol of the fourth MTP3 user protocol instance MUPI4 is encoded by the second adaptor A2 in the one or more IP packets, e.g. as destination port or in the payload of an IP packet. The IP packets transmitting the MTP3 user signalling message are routed in the IP domain to the signalling gateway SG. In the signalling gateway SG the MTP3 user signalling message transmitted as one or more internet protocol packets is received and said signalling message is sent as a message transfer part 3 packet to the fourth MTP3 user protocol instance MUPI2. Via the mapping table MT in the signalling gateway SG the fourth IP address IP4 that has been used as destination IP address is converted into the second signalling point code SPC2 to be used as DPC in the packet according to the MTP3 protocol. Accordingly the second D? address D?2 that has been used as source IP address is converted into the fourth signalling point code SPC4 to be used as OPC in the packet according to the MTP3 protocol. The indication of the kind of MTP3 user protocol that has been encoded in the one or more IP packets, e.g. as port or in the payload of an IP packet is converted to the second service SI2 indicator of the MTP3 user signalling message. The MTP3 user signalling message is transmitted in the MTP domain from the signalling gateway SG to the fourth MTP3 protocol instance MPI2. The second MTP protocol instance MPI2 identifies the second MTP3 user protocol instance MUPI2 according to the second service indicator SI2 and forwards the signalling message to the fourth MTP3 user protocol instance MUPI2.

The message flow between protocol instances of an MTP3 user protocol within the IP domain is shown by example of an MTP3 user signalling message sent from the first

MTP3 user protocol instance MUPI3 to the second MTP3 user protocol instance MUPI4. In this signalling message the third signalling point code SPC3 is used as OPC and the fourth signalling point code SPC4 is used as DPC. The MTP3 user signalling message is conveyed in one or more IP packets by the first protocol instance of the connectionless transport protocol CTP1. The first adaptor Al performs a conversion from the third signalling point code SPC3 to the first IP address IP1 and from the fourth signalling point code SPC4 to the second IP address IP2. In the IP packets transmitting the MTP3 user signalling message, the second IP address IP2 is used as destination LP address and the first IP address IP1 is used as source IP address. The kind of MTP3 user protocol of the fourth MTP3 user protocol instance MUPI4 is encoded by the second adaptor A2 in the one or more IP packets, e.g. as destination port or in the payload of an IP packet. The IP packets transmitting the MTP3 user signalling message are routed in the IP domain to the second protocol instance of the IP protocol IPPI2. From the there the signalling message is handed over via the second protocol instance of the connectionless transport protocol CTP2 and the second adaptor A2 to the second protocol instance of the message transfer part 3 user protocol MUPI4. The kind of message transfer part 3 user protocol can be determined by the first adaptor A2 according to the destination port or according to the indication of the kind of MTP3 protocol that has been encoded in the payload of the IP packet. The second adaptor A2 converts the second IP address IP2 that has been used as destination IP address to the fourth signalling point code SPC4 as DPC and the first IP address IP1 that has been used as source D? address to the third signalling point code SPC3 as OPC.

Figure 2 depicts a signalling gateway SG between an IP domain and an MTP domain of a telecommunication network. Signalling messages according to an MTP3 user protocol can be transmitted according to the MTP3 protocol in the MTP domain and according to a connectionless transport protocol in the IP domain of the telecommunication network.

The signalling gateway SG is adapted to receive and send signalling messages transmitted between the protocol instances of the message transfer part 3 user protocol. Particularly the signalling gateway SG is adapted to receive said signalling messages transmitted according to the transmission protocol of one of the domains and send said signalling message according to the transmission protocol of the respective other domain. I.e. the signalling gateway SG is adapted to receive a signalling message transmitted according the message transfer part 3 protocol and to send said signalling message according to the connectionless transport protocol and the signalling gateway SG is adapted to receive a signalling message transmitted according to the connectionless transport protocol and send said signalling message according to the message transfer part protocol.

The signalling gateway SG comprises an internet protocol input link IPB for receiving IP packets that transmit MTP3 user signalling messages, an internet protocol output link JPOL for sending IP packets that transmit MTP3 user signalling messages, an MTP input link MTPE for receiving MTP3 packets transmitting MTP3 user signalling messages, and an MTP output link MTPOL for transmitting MTP3 packets transmitting MTP3 user signalling messages. The signalling gateway SG further comprises functional units that can be implemented in hardware, in software or in a combination of hardware and software. The functional units can be implemented on a single physical entity or the functional units can be implemented on a distributed system using different physical entities. The functional units are an JP (internet protocol) address discriminator IP AD, an SS7 (signalling system number 7) agent SS7A, a link selector LS, a routing and messaging control handler RMCH, an SPC (signalling point code) discriminator SD, an IP (internet protocol) agent PA, a next hop selector NHS, and an MTP3 signalling network management function SNMF. Functional flows between the functional units are depicted as arrows.

The signalling gateway SG is adapted to receive via the MTP input link MTPIL MTP3 user signalling messages transmitted according to an MTP3 protocol comprising an OPC as signalling point code of the sending MTP3 protocol instance and a DPC as signalling point code of the addressed MTP3 protocol instance. An MTP3 user signalling message is received in the SPC discriminator SD that is adapted to determine according to the DPC of the MTP3 user signalling message, whether the DPC is used for addressing an MTP3 user protocol instance in the MTP domain or for addressing an MTP3 user protocol instance in the IP domain. If the DPC is used for addressing an MTP3 user protocol instance in the MTP domain the MTP3 user signalling message is forwarded to the link selector LS, that determines according to the DPC of the MTP3 user signalling message an STP (signalling transfer point), to which it forwards the MTP3 user signalling message. The signalling gateway operates as an STP (signalling transfer point) for signalling messages received via the MTP input link MTPIL and transmitted via the MTP output link MTPOL.

If the DPC is assigned to an MTP3 user protocol instance in the IP domain of the telecommunication network, the MTP3 user signalling message is forwarded to the IP agent IPA. The IP agent IPA receives a signalling message transmitted according the message transfer part 3 protocol and sends said signalling message according to the connectionless transport protocol as one or more IP packets. The IP agent IPA comprises a mapping table for conversion from a signalling point code used for addressing a protocol instance of an MTP3 user protocol to an IP address used for addressing said protocol instance. Using this mapping table an OPC according to the MTP3 protocol is converted to a source IP address of the one or more IP packets transmitting the MTP3 user signalling message. Furthermore the mapping table is used to convert the DPC according to the MTP3 protocol, to the source IP address of the one or more IP packets transmitting the MTP3 user signalling message. Additionally in the mapping a network indication can be taken into account to determine the source IP address and the destination IP address. The SI (service indicator) indicating the kind of MTP3 user protocol can be encoded in the one ore more IP packets e.g. in the destination port according to the connectionless transport protocol or in the payload of the one or more IP packets. The IP packets that transmit the MTP3 user signalling message are transmitted by the IP agent IPA to the next hop selector NHS, which determines according to the destination IP address of the one or more IP packets a router to which it sends the one or more IP packets transmitting the MTP3 user signalling message. The one or more IP packets are sent to the determined router via the IP output link IPOL.

In a preferred embodiment of the invention the signalling gateway SG provides a conversion from a network management primitive according to the message transfer part 3 protocol to a network status indication for the IP domain of the telecommunication network. To this purpose the SPC discriminator SD forwards a network management primitive according to the message transfer part 3 protocol to the MTP3 signalling network management function SNMF. The MTP3 signalling network management function SNMF analyses the network management primitive and instructs the routing and messaging control handler RMCH to generate one or more a status indications for the IP domain of the telecommunication network.

The signalling gateway SG is adapted to receive via the IP input link IPIL an MTP3 user signalling message transmitted according to the connectionless transport protocol as one or more IP packets. In the IP packets a source IP address is used for addressing the sending protocol instance of an MTP3 user protocol. Accordingly a destination IP address is used for addressing the receiving protocol instance of an MTP3 user protocol. The one or more IP packets are received in the IP address discriminator IP AD that is adapted to determine according to the destination IP address of the one or more IP packets whether said destination IP address is used for addressing an MTP3 user protocol instance in the MTP domain or an MTP3 user protocol instance in the IP domain. If the destination IP address is used for addressing an MTP3 user protocol instance in the IP domain, the one or more IP packets are forwarded to the next hop selector NHS. The NHS determines according to the destination IP address an IP router to which it sends the one or more IP packets. The signalling gateway SG operates as an IP router for IP packets received from the IP (internet protocol) input link IPIL and transmitted via the internet protocol output link IPOL.

If the destination IP address is used for addressing an MTP3 user protocol instance in the MTP domain of the telecommunication network, the one or more IP packets transmitting the MTP3 user signalling message are forwarded to the MTP agent MTPA. The MTP agent MTPA is adapted to receive a signalling message transmitted according to the connectionless transport protocol as one or more IP packets and send said signalling message according to the message transfer part protocol. The MTP agent MTPA comprises a mapping table for conversion from an IP address used for addressing a protocol instance of an MTP3 user protocol to a signalling point code used for addressing said protocol instance. Using this mapping table a source IP address of the one or more IP packets transmitting the MTP3 user signalling message is converted to an OPC according to the MTP3 protocol. Furthermore the mapping table is used to convert the destination D? address of the one or more IP packets to a DPC according to the MTP3 protocol. Additionally in the mapping the destination IP address can be taken into account to determine a network indicator. The service indicator indicating the kind of MTP3 user protocol can be determined from an indication of the kind of MTP3 user protocol that is transmitted in the payload of the one or more IP packets or from a in the destination port according to the connectionless transport protocol. The MTP3 user signalling message is sent by the MTP agent MTPA to the link selector LS which determines according to the DPC an STP (signalling transfer point) to which it sends the MTP3 user signalling message. The signalling message is sent to the determined STP via the MTP output link MTPOL. In a preferred embodiment of the invention the signalling gateway SG provides a conversion from a network status indication of the IP domain of the telecommunication network to network management primitive according to the message transfer part 3 protocol to a network. To this purpose the IP address discriminator IP AD forwards network status indication of the IP domain to the routing and messaging control handler RMCH. The routing and messaging control handler RMCH analyses the status indication and instructs the signalling network management function SNMF to generate one or more network management primitives for the MTP domain of the telecommunication network.

Figure 3 depicts an adaptor A according to the invention. The adaptor A connects a protocol instance of an MTP3 user protocol to a protocol instance of a connectionless transport protocol CTPI. Furthermore the adaptor A is connected to a protocol instance of a network management protocol NMPI. The network management protocol can be e.g. an ICMP (Internet Control Message Protocol), an OSPF (Open Shortest Path First) protocol, or an ECN (Explicit Congestion Notification) protocol. The protocol instance of the connectionless transport protocol CTPI and the protocol instance of the network management protocol NMPI are connected to a protocol instance of the internet protocol IPPI.

The adaptor A comprises a signalling message mapping unit SMMU, a network management primitive mapping unit NMPMU, and an MTP3 service interface MSI connected to a protocol instance of an MTP3 user protocol via a connection C. The functional units of the adaptor A can be implemented on a single physical entity or the functional units can be implemented on a distributed system using different physical entities. The connectionless transport protocol can be for example a UDP (User Datagram Protocol).

The protocol instance of the connectionless transport protocol CTPI is adapted to receive from the IP protocol instance IPPI one or more IP packets transmitting an MTP3 user signalling message. It provides the received signalling message as one or more packets according to the connectionless transport protocol to the signalling message mapping unit SMMU. The signalling message mapping unit SMMU is adapted to convert the received packets according to the connectionless transport protocol to an MTP3 SAP (service access point) primitive or to an MTP3 message. The signalling message mapping unit SMMU comprises a mapping table for conversion between an IP address used for addressing a protocol instance of an MTP3 user protocol and an SPC used for addressing said protocol instance in the MTP domain. Using this mapping table a source IP address is converted to an SPC, which is used as OPC. In an embodiment of the invention, the mapping table can provide a mapping between an IP address used for addressing a protocol instance of an MTP3 user protocol and a combination of a NI (network indicator) and a signalling point code used for addressing said protocol instance. In this case an NI can be additionally determined from the source IP address using the mapping table. Furthermore the mapping table is used to convert a destination IP address to an SPC, which is used as DPC. Furthermore packets according to the connectionless transport protocol can comprise an indication of the MTP3 user protocol the MTP3 message is referring to. This indication of the MTP3 user protocol can be for example encoded in the destination port according to the connectionless transport protocol.

Alternatively the indication of the MTP3 user protocol can be encoded in the payload of the packet according to the connectionless transport protocol. Said indication can be converted to a service indicator identifying the kind of MTP3 user transport protocol the MTP3 user signalling message is destined to. The signalling message mapping unit transmits the MTP3 user signalling message via the service interface MSI to a protocol instance of an MTP3 user protocol.

In a preferred embodiment of the invention the adaptor provides a conversion from a network status indication of the IP domain of the telecommunication network to network management primitive according to the message transfer part 3 protocol. To this purpose the network management protocol instance NMPI forwards a network status indication of the IP domain to the network management primitive mapping unit NMPMU. The network management primitive mapping unit NMPMU analyses the status indication and generates one or more MTP3 SAP (service access point) primitives that are forwarded via the MTP3 service interface MSI to the MTP3 user protocol instance. The MTP3 service interface MSI is adapted to receive via the connection C an MTP3 user signalling message from a protocol instance of an MTP3 user protocol. The MTP3 service interface MSI forwards the MTP3 user signalling message to the signalling message mapping unit SMMU. The signalling message mapping unit SMMU converts the MTP3 user signalling message to one or more packets according to the connectionless transport protocol transmitting said MTP3 user signalling message. The signalling message mapping unit SMMU comprises a mapping table for conversion between a signalling point code used for addressing a protocol instance of an MTP3 user protocol and an IP address used for addressing said protocol instance. Using this mapping table the DPC of the MTP3 user signalling message is converted to a destination IP address and the OPC of the MTP3 user signalling message is converted to a source IP address. In an embodiment of the invention the mapping table can provide a conversion from a combination of an NI (network indicator) and an SPC (signalling point code) to an IP address. In this case the NI can be taken into account in the determination of the source IP address from the OPC or in the determination of the destination IP address from the DPC. The SI (service indicator) indicating the kind of MTP3 user protocol can be encoded in the packets according to the connectionless transport protocol e.g. in the destination port according to the connectionless transport protocol or in the payload of the packets according to the connectionless transport protocol. The MTP3 user signalling message is forwarded to the protocol instance of a connectionless IP user transport protocol CTPI that transmits it further via the IP protocol instance IPPI to an IP network.

Figure 4 depicts a mapping in a signalling gateway between protocol fields of an IP packet IPP transmitting an MTP3 user signalling message and protocol fields of an MTP3 packet MTP3P transmitting said MTP3 user signalling message. Only protocol fields of the MTP3 packet MTP3P and of the IP packet IPP are shown that refer to the embodiment of the invention. The protocol fields are shown for illu strati on al purposes. The order of the protocol fields does not necessarily reflect the order of the bits in the respective packet. An MTP3 packet comprises a service indicator octet SIO, an SS7 routing label SS7RL, and MTP user specific protocol elements MTPUPE. The service indicator octet SIO comprises a network indicator NI and a service indicator SI. The network indicator NI can indicate a subnetwork within a signalling network in which the MTP3 user signalling message is transmitted. The service indicator SI indicates the kind of MTP3 user protocol to which the payload of the signalling message is related. The SS7 routing label SS7RL comprises a destination point code DPC, an originating point code OPC, and a signalling link selection code SLS. The originating point code OPC is used for addressing a protocol instance of an MTP3 user protocol sending the MTP3 user signalling message. The destination point code DPC is used for addressing a protocol instance of an MTP3 user protocol to which the MTP3 user signalling message is addressed.

A packet according to a connectionless transport protocol, e.g. UDP is encapsulated by the IP packet IPP. The IP packet IPP comprises an IP protocol header IPH, a header of the connectionless IP user transport protocol CNLTPH, and payload of the connectionless transport protocol CNLP. The IP header comprises a destination IP address DIP, a source IP address SIP and a protocol identification PDD. The source IP address SD? is used for addressing a protocol instance of an MTP3 user protocol sending the MTP3 user signalling message. The destination IP address DIP is used for addressing a protocol instance of an MTP3 user protocol to which the MTP3 user signalling message is sent. The protocol identification ID indicates the kind of connectionless IP user transport protocol. The header of the connectionless IP user transport protocol CNLTPH comprises a destination port DP and a source port SP.

Furthermore figure 4 depicts the mapping table MT and a conversion function CF. The mapping table MT provides a mapping between a signalling point code used for addressing a protocol instance of an MTP3 user protocol and an IP address used for addressing this protocol instance. In a further embodiment of the invention, the mapping table MT provides a mapping from a combination of a network indicator NI and a signalling point code used for addressing a protocol instance of an MTP3 user protocol to an IP address used for addressing this protocol instance and vice versa. In the conversion from an MTP3 packet MTP3P transmitting an MTP3 user signalling message to one or more IP packets IPP transmitting said signalling message the service indicator SI of the MTP3 packet MTP3P can be converted to the destination port DP of the protocol header of the connectionless transport protocol CNLTPH using the conversion function CF. Additionally also the source port CP can be determined from the service indicator SI. Alternatively the service indicator SI can be encoded in the payload of the connectionless transport protocol CNLP.

Accordingly in the conversion from one or more IP packets IPP transmitting an MTP3 user signalling message to an MTP3 packet MTP3P transmitting said signalling message a destination port DP of the protocol header of a connectionless transport protocol CNLTPH can be converted to the service indicator SI of the MTP3 packet using the conversion function CF. Alternatively the service indicator SI can be extracted from the payload of the connectionless transport protocol CNLP.

In the conversion from an MTP3 packet MTP3P transmitting an MTP3 user signalling message to one or more IP packets IPP transmitting said signalling message the destination point code DPC of the MTP3 packet MTP3P can be converted to a destination IP address DIP of an IP packet IPP using the mapping table MT. Alternatively a combination of the network indicator NI and the destination point code DPC can be converted to a destination IP address DIP of an IP packet IPP using the mapping table MT. In the conversion from one or more IP packets transmitting an MTP3 user signalling message to an MTP3 packet transmitting said signalling message a destination IP address DIP of an IP packet IPP can be converted to the destination point code DPC of the MTP3 packet. Alternatively a destination IP address DIP of an IP packet IPP can be converted to a combination of the network indicator NI and the destination point code DPC of the MTP3 packet MTP3P using the mapping table MT.

In the conversion from an MTP3 packet MTP3P transmitting an MTP3 user signalling message to one or more IP packets IPP transmitting said signalling message the originating point code OPC of the MTP3 packet MTP3P can be converted to a source IP address SIP of an IP packet IPP using the mapping table MT. Alternatively a combination of the network indicator NI and the originating point code OPC can be converted to a source IP address SIP of an IP packet IPP using the mapping table MT. In the conversion from one or more IP packets IPP transmitting an MTP3 user signalling message to an MTP3 packet MTP3P transmitting said signalling message a source IP address SIP of an IP packet IPP can be converted to the originating point code OPC of the MTP3 packet. Alternatively a source JP address SIP of an IP packet IPP can be converted to a combination of the network indicator NI and the originating point code OPC of the MTP3 packet MTP3P using the mapping table MT.

In the conversion from an MTP3 packet MTP3P transmitting an MTP3 user signalling message to one or more IP packets JPP transmitting said signalling message the signalling link selection code SLS of the MTP3 packet MTP3P can be encoded in the connectionless payload CNLP of an IP packet IPP. Accordingly in the conversion from one or more IP packets IPP transmitting an MTP3 user signalling message to an MTP3 packet MTP3P transmitting said signalling message the signalling link selection code SLS of the MTP3 packet MTP3P can be extracted from the connectionless payload CNLP of an IP packet PP.

Furthermore in the conversion from an MTP3 packet transmitting an MTP3 user signalling message to one or more IP packets transmitting said signalling message MTP3 user specific protocol elements MTPUPE of the MTP3 packet MTP3P can be encoded in the connectionless payload CNLP of an IP packet JPP. Accordingly in the conversion from one or more JP packets transmitting an MTP3 user signalling message to an MTP3 packet MTP3P transmitting said signalling message the MTP3 user specific protocol elements MTPUPE can be extracted from the connectionless payload CNLP of an IP packet IPP.

Claims

1. Telecommunication network for transmitting signalling messages between a first protocol instance (MUPI3) and a second protocol instance (MUPI4) of a message transfer part 3 user protocol in a first domain of the telecommunication network, wherein in said first domain signalling messages between the protocol instances are transmitted according to a connectionless transport protocol and the protocol instances are addressed using transport addresses, wherein each of the first and the second protocol instance (MUPI3; MUPI4) is connected to the connectionless transport protocol via an adaptor (Al ; A2; A) providing a conversion from a message transfer part 3 user address comprising at least one of a signalling point code, a network indicator and a service indicator to a transport address used for addressing the respective protocol instance and vice versa.

2. Telecommunication network according to claim 1 comprising a third protocol instance (MUPIl) of the message transfer part 3 user protocol in a second domain of the telecommunication network, wherein in said second domain signalling messages between the protocol instances are transmitted according to a message transfer part 3 protocol and the protocol instances are addressed using a message transfer part 3 user address comprising at least one of a signalling point code, a network indicator and a service indicator, and wherein the first protocol instance (MUPI3) is addressable from the second domain using a message transfer part 3 user address, the third protocol instance (MUPIl) being addressable from the first domain using a transport address, and wherein the telecommunication network comprises a signalling gateway (SG) connecting the first and the second domain, the signalling gateway (SG) providing conversion from a message transfer part 3 user address used for addressing a protocol instance to a transport address used for addressing said protocol instance and vice versa, the signalling gateway (SG) being adapted to receive a signalling message transmitted according to the transmission protocol of one of the domains and to send said signalling message according to the transmission protocol of the respective other domain, and the telecommunication network further comprises means for differentiating (SD;

PAD) according to a destination address of a signalling message between a signalling message destined to a protocol instance in the first domain and a signalling message destined to a protocol instance in the second domain and the telecommunication network comprising routing means (SD; IP AD) for routing a signalling message towards the first or the second domain according to the result of said differentiation.

3. Telecommunication network according to claim 2 for transmitting signalling messages according to different kinds of message transfer part 3 user protocols, wherein in the first domain a signalling message comprises an indication of the message transfer part 3 user protocol the signalling message complies with, and wherein the adaptor (Al ; A2; A) connecting the first or the second protocol instance (MUPI3; MUPI4) to the connectionless transport protocol and the signalling gateway (SG) provide a conversion from the indication of the message transfer part 3 user protocol to a service indicator identifying the message transfer part 3 user protocol and vice versa.

4. Adaptor (Al ; A2; A) for connecting a protocol instance (MUPI3; MUPI4) of a message transfer part 3 user protocol to a connectionless transport protocol, the adaptor (Al; A2; A) providing a conversion from a message transfer part 3 user address used for addressing a protocol instance, to a transport address used for addressing assigned to said protocol instance and vice versa, the message transfer part

3 user address comprising at least one of a signalling point code, a network indicator and a service indicator.

5. Adaptor (Al; A2; A) according to claim 4 for connecting protocol instances (MUPI3; MUPI4) of message transfer part 3 user protocols of different kinds to the connectionless transport protocol, the adaptor (Al ; A2; A) providing a conversion from a service indicator identifying the message transfer part 3 user protocol to an indication of the message transfer part 3 user protocol transmitted in a packet according to the connectionless transport protocol and vice versa.

6. Adaptor (Al; A2; A) according to any of the claims 4 or 5, wherein the adaptor (Al; A2; A) provides a conversion from a status indication of the first domain of the telecommunication network to a network management primitive according to the message transfer part 3 protocol and vice versa.

7. Adaptor (Al; A2; A) according to any of the claims 4 to 6 wherein the connectionless transport protocol is a User Datagram Protocol.

8. Signalling gateway (SG) connecting a first and a second domain of a telecommunication network, wherein in the first domain signalling messages between protocol instances of a message transfer part 3 user protocol are transmitted according to a connectionless transport protocol, the protocol instances being addressed using transport addresses and in the second domain signalling messages between protocol instances of the message transfer part 3 user protocol are transmitted according to a message transfer part 3 protocol, the protocol instances being addressed using message transfer part 3 user addresses comprising at least one of a signalling point code, a network indicator and a service indicator, the signalling gateway (SG) providing a conversion from a message transfer part user address used for addressing a protocol instance to a transport address used for addressing said protocol instance and vice versa, and the signalling gateway (SG) being adapted to receive a signalling message transmitted according to the transmission protocol of one of the domains and to send said signalling message according to the transmission protocol of the respective other domain.

9. Signalling (SG) gateway according to claim 8 for transmitting signalling messages according to different kinds of message transfer part protocols, wherein in the first domain a signalling message transmitted according to the connectionless transport protocol comprises an indication of the message transfer part 3 user protocol the signalling message complies with, the signalling gateway (SG) providing a conversion from the indication of the message transfer part 3 user protocol to a service indicator identifying the message transfer part 3 user protocol and vice versa.

10. Signalling gateway (SG) according to claims 8 or 9, adapted to perform a conversion from a status indication of the first domain of the telecommunication network to a network management primitive according to the message transfer part 3 protocol and vice versa.

11. Signalling gateway (SG) according to any of the claims 8 to 10, wherein the connectionless internet protocol user protocol is a User Datagram Protocol.