Classifications

• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
  • H04L65/00—Network arrangements, protocols or services for supporting real-time applications in data packet communication
  • H04L65/10—Architectures or entities
  • H04L65/102—Gateways
  • H04L65/1033—Signalling gateways
  • H04L65/104—Signalling gateways in the network
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
  • H04L12/00—Data switching networks
  • H04L12/64—Hybrid switching systems
  • H04L12/6418—Hybrid transport
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
  • H04L61/00—Network arrangements, protocols or services for addressing or naming
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
  • H04L65/00—Network arrangements, protocols or services for supporting real-time applications in data packet communication
  • H04L65/10—Architectures or entities
  • H04L65/102—Gateways
  • H04L65/1023—Media gateways
  • H04L65/103—Media gateways in the network
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
  • H04L65/00—Network arrangements, protocols or services for supporting real-time applications in data packet communication
  • H04L65/10—Architectures or entities
  • H04L65/102—Gateways
  • H04L65/1043—Gateway controllers, e.g. media gateway control protocol [MGCP] controllers
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
  • H04L69/00—Network arrangements, protocols or services independent of the application payload and not provided for in the other groups of this subclass
  • H04L69/08—Protocols for interworking; Protocol conversion
  • H04L69/085—Protocols for interworking; Protocol conversion specially adapted for interworking of IP-based networks with other networks
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
  • H04L69/00—Network arrangements, protocols or services independent of the application payload and not provided for in the other groups of this subclass
  • H04L69/16—Implementation or adaptation of Internet protocol [IP], of transmission control protocol [TCP] or of user datagram protocol [UDP]
  • H04L69/169—Special adaptations of TCP, UDP or IP for interworking of IP based networks with other networks 
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04M—TELEPHONIC COMMUNICATION
  • H04M7/00—Arrangements for interconnection between switching centres
  • H04M7/12—Arrangements for interconnection between switching centres for working between exchanges having different types of switching equipment, e.g. power-driven and step by step or decimal and non-decimal
  • H04M7/1205—Arrangements for interconnection between switching centres for working between exchanges having different types of switching equipment, e.g. power-driven and step by step or decimal and non-decimal where the types of switching equipement comprises PSTN/ISDN equipment and switching equipment of networks other than PSTN/ISDN, e.g. Internet Protocol networks
  • H04M7/124—Arrangements for interconnection between switching centres for working between exchanges having different types of switching equipment, e.g. power-driven and step by step or decimal and non-decimal where the types of switching equipement comprises PSTN/ISDN equipment and switching equipment of networks other than PSTN/ISDN, e.g. Internet Protocol networks where PSTN/ISDN interconnects two networks other than PSTN/ISDN
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04Q—SELECTING
  • H04Q3/00—Selecting arrangements
  • H04Q3/0016—Arrangements providing connection between exchanges
  • H04Q3/0025—Provisions for signalling
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
  • H04L12/00—Data switching networks
  • H04L12/64—Hybrid switching systems
  • H04L12/6418—Hybrid transport
  • H04L2012/6472—Internet
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
  • H04L12/00—Data switching networks
  • H04L12/64—Hybrid switching systems
  • H04L12/6418—Hybrid transport
  • H04L2012/6486—Signalling Protocols
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
  • H04L69/00—Network arrangements, protocols or services independent of the application payload and not provided for in the other groups of this subclass
  • H04L69/16—Implementation or adaptation of Internet protocol [IP], of transmission control protocol [TCP] or of user datagram protocol [UDP]
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
  • H04L69/00—Network arrangements, protocols or services independent of the application payload and not provided for in the other groups of this subclass
  • H04L69/30—Definitions, standards or architectural aspects of layered protocol stacks
  • H04L69/32—Architecture of open systems interconnection [OSI] 7-layer type protocol stacks, e.g. the interfaces between the data link level and the physical level
  • H04L69/322—Intralayer communication protocols among peer entities or protocol data unit [PDU] definitions
  • H04L69/329—Intralayer communication protocols among peer entities or protocol data unit [PDU] definitions in the application layer [OSI layer 7]
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04M—TELEPHONIC COMMUNICATION
  • H04M7/00—Arrangements for interconnection between switching centres
  • H04M7/06—Arrangements for interconnection between switching centres using auxiliary connections for control or supervision, e.g. where the auxiliary connection is a signalling system number 7 link

Definitions

• the present invention relates to a communications network, and in particular to a network handling traffic which conforms to a packet-based internetworking protocol.
• IP Internet Protocol
• IP Internet Protocol
• Several protocols, such as RSVP have not to date been wholly successful.
• a method of operating a telecommunications network in which network traffic conforming to a packet-based inter-networking protocol is communicated between network nodes using a circuit-switched messaging protocol, and subsequently the said traffic is transmitted from one of the said network nodes to a customer terminal.
• the present invention provides for the first time a method of communicating traffic in a telecommunications network using a hybrid protocol in which data conforming to a packet-based protocol such as Internet protocol is carried over a circuit-switched messaging layer.
• This approach makes it possible to provide for the traffic the quality of service guarantees needed for successful implementation of services such as internet telephony, whilst maintaining many of the advantages in terms of flexibility and ease of implementation of Internet protocol and other packet-based protocols.
• this approach greatly facilitates integration between the communications network and associated computer systems.
• traffic is used here, as is conventional in the field of telecommunications networks, to indicate the signals carrying communications between the end users of the network, e.g. telephone calls, as opposed to any other signals present in the network, such as the control signals conventionally carried on the common channel signalling network, or network management signalling.
• the packet-based inter-networking protocol is Internet Protocol (IP).
• IP Internet Protocol
• the circuit-switched messaging protocol is a common channel signalling protocol, and more preferably is signalling system number 7 (SS7) MTP (message transport part).
• SS7 signalling system number 7
• Internet protocol encompasses IP version 4 and
• IP version 6 as defined by the Internet engineering task force (IETF) or any like protocol technically compatible with those protocols.
• Signalling System number 7 is
• SS7 is defined by the ITU and is a widely adopted and stable common channel signalling protocol developed for use in telephony networks.
• the method includes steps of receiving data packets conforming to the said packet-based inter-networking protocol, converting addresses carried in the said packets to origination codes and destination codes of a circuit-switched network, and writing the said codes in a signal conforming to the circuit-switched messaging protocol.
• This preferred approach to implementing the invention uses, e.g., a lookup table to convert addresses of a packet-based network to corresponding origination and destination codes of a circuit-switched network.
• a method of communicating packet data via a telecommunications network which telecommunications network includes a circuit-switched signalling network which supports a predetermined messaging protocol, the method including converting the said packet data to a signal conforming to the said predetermined messaging protocol, communicating the converted packet data via the signalling network, and subsequently recovering the packet data from the said signal.
• a node including means for converting data conforming to a packet-based internetworking protocol to a format conforming to a circuit-switched signalling protocol, and means for outputting a signal in the said format onto a communications network.
• the node may be a trunk or exchange switch, as in the example described below, or may be an edge-of-network terminal such as a personal computer, an intelligent telephone or a mobile Java terminal.
• FIG. 1 is a schematic showing a communications network embodying the invention
• Figure 2 shows a protocol stack for a system embodying the invention
• Figure 3 shows a look-up table used in the IP/MTP layer of Figure 2;
• FIGS 4 to 1 5 are SDL diagrams for a system embodying the invention;
• Figure 1 6 shows a signal communicated in IP over MTP format via an intermediate node.
• DESCRIPTION OF EXAMPLES A telecommunications network includes a number of digital main switch units (DMSU's) 1 which are connected by a common channel signalling network 2 to each other and to local exchanges 3. Each trunk exchange and at least some of the local exchanges include a data interface 10.
• the data interface of one of the DSMU's is connected to a data server 4.
• This data server might be used, for example, to source a packetised MPEG- encoded video data stream in an internet video-on-demand (VoD) application.
• a data terminal, 5, which may be a personal computer, is connected to the data interface of one of the local exchanges.
• the data server transmits data, such as VoD programme material, as Internet Protocol (IP) packets to the data interface of the DMSU.
• IP Internet Protocol
• the data packets carry, in this example, the internet address of the data terminal.
• the data packets are processed within an IP/MTP convergence layer for transmission over the common channel signalling network using SS7 Message Transfer Part protocol.
• the converted packets are then carried within the signalling network to the local exchange.
• the convergence layer carries out a complementary function, converting data from the MTP layer into IP packets for forwarding to the customer data terminal.
• FIG. 2 shows the IP over MTP protocol stack of the system described above.
• the IP/MTP convergence layer carries out functions of address mapping, signalling link selection, encapsulation of IP messages and support of relevant MTP primitives.
• the address mapping function converts IP addresses to MTP point codes and vice versa. In the present example, this done using a look-up table, as illustrated in Figure 3. This converts the source and destination IP addresses to originating point code (OPC) and destination point code (DPC) respectively.
• OPC originating point code
• DPC destination point code
• a service indicator in the MTP SIO field is set to identify IP as the MTP user.
• the convergence layer is also responsible for selecting the signalling link within the SS7 network to be used in conveying the data, and indicates this selection to the MTP layers.
• the MTP makes use of this indication in selecting a physical link for transmission, although the MTP logic may choose a different link in the selection indicated is unavailable.
• the step of selecting the signalling link by the convergence layer may be carried out, for example, by stepping round a cycle of all possible link numbers, with a new link selected for each IP packet, other than when an IP packet is fragmented, in which case the fragmented packets are sent on the same link to ensure a high probability that the packets are received in the correct order.
• IP messages are encapsulated in the signalling information field SIF of an MTP Message Signal Unit (MSU), immediately following an MTP level routing label.
• MSU MTP Message Signal Unit
• the IP message is sent to MTP level 3 in an MTP-transfer primitive.
• the size of the IP message needs to be less than or equal to 268 octets. IP messages longer than this are fragmented by the IP layer.
• the MTP layers of the system are required to support SIFs of 272 octets in order to accommodate the IP message and an MTP level 3 routing label.
• the IP / MTP convergence layer supports the following MTP level 3 primitives:
• the MTP-transfer request and indication primitives are used to transmit and receive, respectively, IP messages to and from the remote host.
• the point code of the remote host is given by the DPC parameter.
• the OPC parameter indicates the point code of the originating the message.
• the SLS and SIO will be selected as described above.
• the User Data part of the primitive will contain the IP message.
• the inability of the MTP to communicate with its peer is indicated to the IP layer, and any messages requested by IP to be sent to that DPC will be discarded.
• the ability of the MTP to communicate with its peer is indicated to the IP layer, and any messages requested by IP to be sent to that DPC will be transmitted.
• the inability to deliver messages is indicated to the IP layer, and any messages requested by IP to be sent to that DPC will be discarded.
• FIG. 1 shows a connection from originating node A to destination node C passing via intermediate node B.
• the message makes a double pass through the convergence layer, in the course of which the destination point code of the incoming message becomes the origination point code of the outgoing message.
• Figures 4 to 1 5 are SDL (Specification Description Language) diagrams illustrating an implementation of the system described above. These may be compiled using commercially available tools to provide the basis of the software required to implement the convergence layer.
• Figure 4 is a system diagram showing the IP and MTP bidirectional links to and between exchanges.
• Figure 5 formally indicates that the behaviour of the terminating exchange is the same as the originating exchange.
• Figure 6 shows messages to and from the IP/MTP convergence process and the relationship with IP and MTP processes.
• Figure 7 defines the behaviour of the IP/MTP conversion process.
• Figure 8 is a continuation of Figure 7.
• Figure 9 shows a procedure to check whether required DPC is marked as congested.
• Figure 10 shows a procedure to check whether a required DPC is marked unavailable.
• Figure 1 1 shows a congestion control procedure to mark destination point codes as congested when notified by the MTP process and to perform required congestion control.
• Figure 1 2 shows a DPC available procedure to remove any DPC codes marked as unavailable which the MTP process has indicated as now being available.
• Figure 1 3 shows a DPC unavailable procedure to mark DPC unavailable when so indicated by the MTP process.
• Figure 1 4 shows a procedure to find an appropriate signalling link.
• Figure 1 5 is a look-up procedure to translate a received IP address into the origination and destination codes required by MTP.

Landscapes

• Engineering & Computer Science (AREA)
• Computer Networks & Wireless Communication (AREA)
• Signal Processing (AREA)
• Multimedia (AREA)
• Computer Security & Cryptography (AREA)
• Data Exchanges In Wide-Area Networks (AREA)

Priority Applications (1)

Applications Claiming Priority (4)

Publications (1)

Family

ID=8234726

Family Applications (1)

Country Status (3)

Families Citing this family (2)

Family Cites Families (2)

• 1999
  • 1999-03-17 GB GB0021340A patent/GB2353177A/en not_active Withdrawn
  • 1999-03-17 EP EP99910513A patent/EP1066708A1/de not_active Withdrawn
  • 1999-03-17 WO PCT/GB1999/000817 patent/WO1999049636A1/en not_active Application Discontinuation

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events