HK1016770A - Telecommunications apparatus, system and method with an enhanced signal transfer point - Google Patents

Description

Telecommunications apparatus, system and method with enhanced signal transfer point

Technical Field

The present invention relates to telecommunications, and more particularly to an enhanced Signal Transfer Point (STP) that, in addition to providing standard STP functionality, changes point codes in telecommunications signals and supports subscriber components. The enhanced TP may form part of a telecommunications system.

Background

Telecommunication signals are used to transfer information within and between telecommunication networks used by the networks. The signal information is used to operate the telecommunications network so that the network can relay other non-signal information of the network user. Some examples of signal operations are set-up, congestion control and network management, but many more. One well known telecommunications signaling system is signal system #7(SS 7). Currently, SS7 is the primary signaling system used by federal telecommunications providers.

As is known in the art and discussed below, STP transports SS7 signals within an SS7 network and controls various signal links including an SS7 network. This transfer is achieved by the function of the information transfer part (MTP) of the signal point handling the routing label of SS 7. The MTP comprises three layers. Layer 1 and layer 2 are the communication of SS7 information from one point to another over separate signal links. Layer 3 transfers SS7 information over an SS7 network without requiring a separate link transport. In other words, layer 1 and layer 2 are related to transport over separate links, while layer 3 is typically related to transport over an SS7 network.

STP accomplishes its routing at layer 3 by using point codes that identify various signal points in the network. The STP layer 3 will identify the destination point code of the SS7 information and select the appropriate signal link to transfer the information. For example, if switch a signals switch B through STP, the information will contain the destination point code of switch B's signal point (and the origin point code of switch a). The STP will accept this spatial signal from one of the signal links, read the destination point code, and place the information on the appropriate link of switch B.

STP may also control the signaling network by using layer 3 generated management information. In the above example, if there is a signal link between switch a and the STP, the STP may signal switch a instructing it to avoid using the particular link that is blocked or failed.

Telecommunications networks often face the problem of rerouting subscriber traffic between switches. It may be desirable to route traffic from one switch to another, from one switch to multiple switches, from multiple switches to one switch, or from one set of switches to another different set of switches. When traffic accessing a network is directed to a particular switch, the traffic is described as being returned to the switch. Traffic that is going to return to a particular switch may need to return to other switches.

Rerouted user traffic is faced with changing connections between switches. Connections between switches may be added and deleted to create a new network fabric. Any changes in the structure need to be reflected in the signaling system due to the relationship between the signal and the network structure. The usual way to do this is to reprogram the switches and signal each other according to the new configuration. This is a complex and time consuming task. The switch contains a large number of data files that must be reprogrammed according to the new routing scheme.

One prior art system facilitates the transition of trunks from one old switch to a new switch. The system switches point codes of the signal information directed to the old switch in response to a change in trunk allocation from the old switch to the new switch. The converter is arranged between the switch and the STP and processes only signals on signal links connected to the old switch. It outputs point codes using a look-up table. Since a particular trunk is connected to either the new switch or the old switch depending on the assignment, a table may be constructed identifying the particular trunk for the call and assigning the transition point code based on that trunk/switch/point code. The prior art suggests to provide such a conversion function in STP but no further disclosure is made in this regard.

While this existing system may be suitable for a limited solution involving a transition from the old switch to the new switch individual trunk, it does not address the problem of changing the network fabric beyond this limited solution. This prior system is designed to serve two switches such that they share a switch load and have the same signal target. In other words, the system is limited to a situation where the signal that has been transmitted to the old exchange is shared between the old exchange and the new exchange during the transfer of load between the two exchanges.

Because of this limitation, existing systems have not addressed these several problems. Since it is based on identifying individual trunks for point code conversion, signals that cannot be associated with a particular trunk cannot have their point codes converted. Such existing systems do not address the handling of management information generated for control signal systems. And reliance on individual trunk identification does not adequately address the situation where the entire switch load moves between switches, or where multiple switch loads are concentrated on one switch. Since all trunks between switches are changing, there is no need to identify each trunk.

It is important that existing systems do not identify the source of the signal information in order to select the target of the signal. It has been known to systematically identify the information from the new switch and convert the signals to indicate the old switch as the source of the signal. This is done to avoid confusion of the target, but this does not affect the actual selection of the target. In existing systems, the target is not selected based on the source of the information. Existing systems use only trunk identification to select targets. This is detected using one of a dial number or a Circuit Identification Code (CIC).

Another important aspect is to note that existing systems are designed to convert only signals that have been placed on signal links connected to old switches. This means that the STP has separated the signal information directed to the old switch. Therefore, the system cannot see signals directed to other switches and is not equipped with a function of processing signals not directed to the old switch. Thus, an STP added to the system converts the point code only after the STP has routed and specified that the signal is destined for an old switch. Thus, the STP of an existing system does not convert incoming signals that are still to be transmitted and may still be directed to either switch.

Another known system provides a signal gateway between two signal systems, for example, gateways for european and us signal systems. The signal gateway converts the point code according to the network identification and the target point code. The gateway does not convert the point code according to source information such as signal links or source point codes. The gateway also converts the point code after the point code has been used for information transfer. In addition, since the gateway has to interface with the signals of different signal systems, it has to include more functionality, which would be more costly than a point transcoder without gateway functionality.

The above application discloses a signal processor. Such a signal processor receives, processes and transmits signals. In some examples, the signal processor does not have a point code to facilitate communication of signal information. In other examples, the signal processor may receive signals that are actually transmitted to the switch but need to be processed by the signal processor rather than the switch. The prior art does not address the need for these signal processors for signal switching.

Typically, STP transports signals between several switches. The present system does not provide an efficient and functional STP capable of converting signals to cause system configuration changes affecting several switches. There is a need for STP that facilitates more architectural changes in telecommunications networks.

Disclosure of Invention

The present invention is an STP, system and method that addresses the problems created by structural changes and requires a signal processor. The STP applies an information transfer part (MTP) function to signal information including a point code. The first device applies a signal data link function, the second device applies a signal link function, and the third device applies a signal network function. Conversion means are added to convert at least some of the point codes in the signal information into different point codes.

The switching means may be located between the routing functions of the second means and the third means. Point code conversion may be performed based on the point code or start information originally contained within the information, such as a particular set of signal links used to transfer the information to the STP. The conversion means may consist of a table that takes as input the selection of point codes or link sets and generates conversion codes. In addition, a Circuit Identification Code (CIC) may be converted along with the point code.

The invention enables the transfer of Integrated Services User Part (ISUP) information to any user part connected to STP. The user part may comprise a signal processor.

A signaling system embodying the present invention comprises a plurality of signal points connected to a signal transfer point. The link may be directed to or through other STPs. The signal points generate and process signal information and transmit them over the link to the STP. The signal information contains codes identifying the source signal point and the target signal point of the information. An enhanced STP according to the present invention is capable of converting a target code of signal information directed to a plurality of signal points.

A method of implementing the present invention includes receiving signal information from a source signal point into a signal transfer point. The signal information contains codes identifying the source signal point and the target signal point of the information. The STP then converts at least a portion of the code in the information to a different code before the STP specifies the signal information for the particular target signal point. The STP then transfers the signal information to the signal link based on the converted code. The conversion is based on the initial information and/or the code of the particular link set used to receive the signal information.

In one embodiment, telecommunications traffic is rerouted between switches. However, the signal points in the switch are not reprogrammed and signals continue to be generated according to the original structure and transmitted to the STP. After rerouting, the STP converts the point code in the information, identifies the switch that actually received the traffic, and transmits the information to the switch based on the converted destination point code.

Advantageously, the switching function is located before the MTP level 3 routing function, resulting in an integrated flexible system. The conversion to select a target may be based on the source of the signal. Management information is also converted to facilitate control of the signaling system.

In another embodiment, the point code transformation in the signal information is performed between the point code of the signal processor and the point codes of the other signal points. This may occur if the signal is transmitted to a signal processor other than the switch, even if the signal information identifies the target point code of the switch. The information of the signal processor may require a transcoding of the source point to another point, i.e. the switch receiving the initial information. In another embodiment, the signal processor may be a subscriber portion of an STP, requiring the transfer of select signal information by the signal processor.

Brief description of the drawings

These and other features, aspects, and advantages of the present invention will become better understood with regard to the following description, appended claims, and accompanying drawings where:

fig. 1 is a block diagram of a signaling system.

Fig. 2 is a block diagram of a telecommunications network including a signal system.

Fig. 3 is a logic block diagram of the SS7 function.

FIG. 4 is a logical block diagram of an aspect of the present invention.

FIG. 5 is a logical block diagram of an aspect of the present invention.

FIG. 6 is a logical block diagram of an aspect of the present invention.

FIG. 7 is a logical block diagram of an aspect of the present invention.

FIG. 8 is a logical block diagram of an aspect of the present invention.

Modes for carrying out the invention

As known to those skilled in the art, current SS7 systems include basic components such as signal points, Signal Transfer Points (STPs), and signal links. The signal points process the signal information to facilitate network operation. The signal link transmits the signal information between signal points. This basic relationship is illustrated in fig. 1, which shows that the basic signal system includes signal points 10-15 and signal links 20-28. The links 20-28 carry signals that operate the network and the actual lines that carry the telecommunications traffic are not shown.

A common example of a signal link is the 56k/bit data link contained in the T1 line. However, these links can take many different forms, such as analog links, satellite links, and 1.5M/bit data links. Typically, these links are divided into a number of associated groups of links, called linksets.

The signal point processes signal information transmitted by the signal link. Typically, the signal points are located within a telecommunications switch. As is known, a switch typically includes a Central Processing Unit (CPU), signal points, and a switch matrix. The signal point is connected to the CPU of the switch and supplies data to the CPU so that it can control the switch matrix. The switches communicate with each other over signal links through their signal points. In this way, the CPU of the switch can coordinate the various switch matrices to establish connections through a series of switches.

The signal point may also be located within a Service Control Point (SCP). As known to those skilled in the art, the SCP includes a database responsive to the switch signal. Generally, the SCP accepts the switch's query as to how to route a particular call. The SCP processes the signal and answers the switch by providing a signal of routing information. In addition to signal relay functions, an STP may also function as a signal point. An STP receives a plurality of signal links from a number of signal points. The primary function of STP is to route the input signal to the appropriate output signal link. Typically, the signal points and SCPs of a switch are connected to a STP and the signal is transmitted to the STP for transmission to an appropriate target signal point in another switch or SCP. STP also functions as a network management for SS 7.

Other types of signal points are equally applicable to the present invention. For example, the signal processor described above may function as a signal point. In addition, other signaling systems, such as the C7 signaling system, are equally applicable to the present invention.

Fig. 2 further illustrates the basic relationship of fig. 1, which is an overlay of fig. 1. Figure 2 shows switches 30-31, STPs 40-41, signal processor 45, and SCP50, each comprising a signal point connected to signal points within other network elements. As discussed, signal points within the switch are typically coupled to a switch CPU that controls the switch matrix.

The SS7 signal is itself a packet, or a message or information bit. The function of processing SS7 signal information is basically divided into two parts: an information transfer part (MTP) and a user part. The function of the MTP is to provide transport of information for SS7 within the signaling system. Those skilled in the art are familiar with the functionality of user parts such as the Integrated Services User Part (ISUP), the Telephone User Part (TUP), the Transaction Capabilities Application Part (TCAP) and the Signal Connection Control Part (SCCP). These functions "leverage" the MTP to transmit signaling information over the signaling links of the SS7 network so that the subscriber portion can process information required by the switch, such as dialed numbers, translated numbers, circuit status, etc.

Since STPs serve to route and manage the SS7 network, they do not require the subscriber portion functions of call and connection information associated with typical telecommunications networks. The STP can pass SS7 information within the signal network to the appropriate signal points and SCPs within the switch. STP accomplishes this function using MTP processing. Additionally, STP may also use Signal Connection Control Part (SCCP) logic to facilitate transport. SCCP may implement the transfer of signal information according to logical connections. For example, signal information requiring translation of dialed numbers may be passed to the STP itself. The SCCP provides the STP with the point code of the appropriate database to accommodate the translation.

The MTP function comprises three layers: signal data link (layer 1), signal link (layer 2), signal network (layer 3). Layer 1 represents a bi-directional signal path containing two data channels working together in opposite directions. Layer 1 defines the physical and electrical characteristics of the signal link. Typically, this requires 56k/bit data link operation, however, other link formats are equally applicable to the present invention. Layer 2 operates on layer 1 and provides point-to-point signaling over a data link. This includes delimitation of the signal information with markers, bit stuffing, error detection by check bits, error correction by forwarding and sequencing information, fault detection of the signal link, and restoration of the signal link. For example, in figures 1 and 2, the first two layers may be used to provide for the transport on signal link 20 to be transferred from signal point 10 of switch 30 to the signal point of STP40 at a rate of 56 k/bit. These first two layers also ensure that the supervisory signal link 20 maintains proper performance. Layer 3 defines the transport functions independent of the operation of the respective signal links. Such as from switch 30 to SCP50 on fig. 2.

The SS7 functionality is illustrated in fig. 3 with MTP61 and user part 62. The MTP and the subscriber part are shown separately. The MTP transports signaling information within the signaling network and the subscriber part facilitates network operation that carries telecommunications services. An example of a user part is a signal processor. The signal data link 71 (layer 1) handles the physical/electrical transport over the individual links, which is associated with the signal link 72 (layer 2) that monitors and controls these individual links. Between the user part (layer 4) and layer 2 a signal network 73 or layer 3 is shown. Layer 3 provides an interface between the user part and the individual link transport. Layer 3 also manages SS7 outside the individual link layer.

Figure 4 shows this function and the specific layer 3 function in more detail. The functions of signal data link 100 (layer 1), signal link 200 (layer 2), signal network 300 (layer 3), and user part 400 (layer 4) have been discussed above. Signal network 300 also includes signal information processing 310 that ensures that the information of user portion 400 is delivered to the appropriate destination, primarily based on routing labels contained within the information. Signal information processing 310 includes authentication 312, routing 314, and assignment 316.

Before discussing these elements, routing labels are briefly described. A routing label is included in each signal message that is used by the associated subscriber section to identify the purpose of the message and by layer 3 to process and transmit the message. The routing label is typically placed at the beginning of the signal information segment. The route label contains a Destination Point Code (DPC) and a source point code (OPC). These point codes identify signal points in the network-in particular the source and target signal points of specific information. For example, when information is transferred from signal point a to signal point B, OPC is a and DPC is B. The return information will reverse both, OPC to B and DPC to a. The route label also contains a Signal Link Selection (SLS) field for load sharing between links.

The standard international signal has 14-bit DPC, 14-bit OPC, and 4-bit SLS. The standard us signal has 24-bit DPC, 24-bit OPC and 5-or 8-bit SLS. The 24 bits of the U.S. point code are divided into three 8-bit fields that identify the signal point, network and network cluster to which the point code belongs. The 8-bit cluster member code 00000000 is reserved for STP. It should be noted that other signal conversions are equally applicable to the present invention.

Referring again to fig. 4, discrimination 312 analyzes the DPC of the message to determine whether a particular signal point is the target of the message (implementing a discrimination function). If there is a different destination, the information is directed to route 314 for transit over the signal network. If it is a target, the information is directed to allocation 316 for internal processing.

The distribution 316 analyzes the service indicators in the information and directs the information to the appropriate users of the user part 400 or to the appropriate part of the signal network management 320.

The routing 314 receives the authentication 312, user part 400 and signal network management 320 information. Route 314 determines the signal link over which the outgoing information is sent and passes the information to layer 2 for transmission. Typically the DPC is used to select a combined link set and the SLS is used to select links within the combined link set in which the information is placed. The actual destination of the DPC control information, but many other factors may affect routing, such as congestion and link failure. Signal network management 320 provides this type of information to route 314.

The signal network management 320 includes the following functions: signal link management 322, signal routing management 324, and signal traffic management 326. The main function of these units is to control the signal network in case of failures and blockages.

Signal link management 322 controls the state of a particular link. It may control the link in the following way: link activation, link failure, link recovery, link set activation, automatic assignment.

Signal routing management 324 distributes information about the link state. The information may indicate a failed or blocked link, which includes: inhibit handoff, allow handoff, limit handoff, control handoff, signal routing group block test, and handoff route set test.

Signal traffic management 326 is used to reroute signals in response to system conditions such as faults or blockages. Signals may be transferred or partially transferred (disabled) from one link to another. These processes are: translation, switch back, forced rerouting, control rerouting, MTP restart, management barring and flow control.

As known to those skilled in the art, STP incorporates the MTP functionality described above. According to the invention, the functionality of STP may be changed to provide advantageous capabilities for a telecommunications system.

Figure 5 shows the function of STP according to the invention. The figure again shows the signal data link 100 (layer 1), the signal link 200 (layer 2), the signal network 300 (layer 3) and the user part 400 (layer 4). Further, authentication 312, routing 314, distribution 316, signal network management 320 are illustrated as functions of signal network 300. The interfaces of these functions are modified as follows.

A point code conversion 500 is added, drawn between layer 2 and layer 3. Point transcoding 500 receives information from layer 2 and provides the information to authentication 312. The point code conversion 500 translates data in the signal information using an internal table. Typically, these tables logically reside within the MTP software of the STP process. These tables are used to systematically change the DPC, OPC, and CIC designations of the signal information directed to the discriminator 312.

The appropriate table may be selected based on the link set or signal cluster to which the information arrives. These link sets and clusters represent the source of the information. These tables may also be selected or entered according to OPC also at the source of the presentation information. These tables may utilize the OPC, DPC and/or CIC of information to select new data to be converted, including new OPC, DPC and/or CIC. Since the route 314 will select the outbound link based on the DPC, the point transcoding 500 may change the actual destination of the signal information. The tables are constructed to effect changes to these requirements.

DPC, on the other hand, is only used for the entire conversion. One table may contain DPC to DPC conversions. Additionally, at a point within the STP that still processes a particular linkset (before layer 3), the MTP linkset processing may place a flag within the information from the specified linkset. This information from a particular link set will access the table during subsequent processing after the tag is detected, and unmarked information will not access the table. The table may convert a combination of OPC, DPC and/or CIC to a specified combination of OPC, DPC and/or CIC.

Referring again to fig. 4, it can be shown how authentication 312 is altered in accordance with the present invention. As discussed, the discrimination 312 determines whether the destination of the information is the STP itself, the subscriber portion, or another signal point. Link set, OPC, DPC and/or CIC based translation table functionality may be placed at this point. The table may process all signal information, DPC information not directed to STP or information that was marked at previous processing. The invention is therefore applied to the point code conversion located at authentication 312. In this case, the converted information is typically transmitted to distribution 316.

In one embodiment, a digital switch company's Megahub model STP is used. The STP has the characteristic of gateway screening. This feature filters the input information with a set of criteria defined for each link set that conveys the information. The criteria ensures that the information is valid for the link set. Currently, this feature only filters information, not converting or mapping to point codes. In this embodiment, the point transcoding 500 is placed at a point within the STP between layer 2 and layer 3 that has gateway screening features. Alternatively, only the flag function may be set on the gateway screening feature and the translation table may translate the flagged information during subsequent processing.

Point code conversion of signal point transmission signals on a given link set may be specified by placing the conversion table at a point within the STP dedicated to the input link set. In other words, the signal transitions may be independently specified at the source of the signal. This placement also allows the layer 3 function to process the converted signal rather than first processing the signal and then converting the point code at the output. Similar advantages can be obtained where information is marked on a particular link set and OPC is used to determine the source during subsequent processing.

The user part 400 (layer 4) may include a signal processor such as that described in 1994, patent application serial No. 08/238,605 entitled "method, system and apparatus for telecommunications control", or that described in a patent application entitled "system for managing telecommunications" (filed concurrently with the present invention), which are all assigned to the same assignee. The signal processor may process a specific ISDN Service User Part (ISUP) signal. In at least one embodiment, discrimination 312 will be configured to identify the particular ISUP message that the signal processor requires. These criteria may form a table identifying the appropriate ISUP message from the authentication 312 for delivery to the application processor. As with the point code conversion table, the source of the signal, as represented by the link set or OPC, can be used to determine whether ISUP should be communicated to the relevant user part. OPC, DPC, SLS, CIC, and various combinations of these units may also be used for this purpose. It will be appreciated by those skilled in the art that other standards may be used to convey information to the signal processor. In addition, during linkset-specific processing, a flag function may also be used to trigger the passing of ISUP to layer 4 users during subsequent processing. Those skilled in the art are familiar with ISUP recognition.

Fig. 6 shows another embodiment, which shows the same elements as fig. 5, except for the addition of a part. In this embodiment, the added point code conversion may satisfy the requirements of the information generated by the signal network management 320 or the user part 400. For these embodiments, a point code conversion 350 is added, which is illustrated between the signal network management 320 and the route 314, as well as between the user part 400 (layer 4) and the route 314. Point code conversion 350 works with the same tables as used in point code conversion 500. In this way, point codes within the management information or from the user part can be converted. In general, like the point code conversion 500, these variations are due to structural variations.

As described above, the signal network management 320 is composed of three functions: signal link management, signal traffic management, and signal routing management. As an example, if a signal link fails, signal link management will sense the failure and report to signal traffic management that transmits signals to other signal points to reroute signals on another link. If this causes another link to be blocked, the signal routing management will transmit signals to other signal points instructing them to restrict the use of the blocked link.

Generally, the signal link management information does not require substantial transcoding. However, both signal traffic management information and signal routing management information provide signal instructions for the affected signal links and points to other signal points. The point code is used to define the affected signal links and points. This information is needed to identify the point code that has changed, resulting in a new network structure. These changes in point codes for routing are affected by the tables discussed above. Management information may be specified for each signal point that receives one of the messages using DPC entries in the routing label into the table. The table is constructed to provide, for each signal point receiving the management information, a point code that it can understand in a given point code conversion scheme.

Figure 7 shows another embodiment illustrating a telecommunications system including an enhanced STP600 operating in accordance with the present invention. STPs 605 and 610 are shown with switches 615, 620, 625, 630, 635, 640, 645, 650, 655, 660, and 665. STPs 605 and 610 are standard STPs known in the art. The switch is a standard telecommunications switch known in the art.

In fig. 7, signal links are indicated by double lines and telecommunications connections are indicated by element lines. As shown in the figure, switches and STPs interconnect signal links 700, 705, 710, 720, 725, 730, 735, 740, 745, and 750. These links pass signals between the switch and the STP as described above. As shown, the switches are interconnected by connections 760, 765, 770, 775, and 780. As is known in the art, these connections carry telecommunications traffic for users of the telecommunications system.

For the understanding of the present embodiment, it should be noted that the system architecture has been modified according to the following architecture (the previous connections are not shown): the connection from switch 620 to switch 650 is changed to switch 640, the connection from switch 625 to switch 655 is changed to switch 645, the connection from switch 630 to switch 660 is changed to switch 645, and the connection from switch 635 to switch 665 is changed to switch 645. The connection of the switches 615 to 650 is unchanged. The switch does not have to be reprogrammed to adapt the new fabric to the signal. In addition, STPs 605 and 610 need not be enhanced in accordance with the present invention.

When switch 630 attempts to connect to switch 660 (its previous connection), it is actually connected to switch 645. However, when it attempts such a connection, switch 630 still directs the signal to switch 660. The signal will be passed to STP600 and processed in accordance with the present invention. The DPC in the signal is converted to represent switch 645 instead of switch 660. The signal is then passed to switch 645. When switch 645 acknowledges the connection in response to switch 630, STP600 will convert the OPC for switch 645, representing switch 660. In this way, the switch 630 can signal and make connections according to the new configuration without reprogramming.

When switch 620 attempts to connect to switch 650 (its previous connection), it is actually connected to switch 640 via connection 765. However, switch 620 still attempts to send a signal to switch 650. Signals are transferred over link 705 through STP605 and to STP600 over link 710. STP600 converts DPCs to represent switch 640 instead of switch 650. The signal is then transmitted on link 745 to switch 640. When switch 615 attempts to connect to switch 650 (its previous and current connections), it will send a signal to switch 650. Signals are transmitted on link 700 through STP605 and to STP600 via link 710. In this case, no conversion is required. Thus, at times STP600 should convert the DPC of switch 650, and at times it should not. The present invention allows STP600 to discern whether a conversion is to be performed.

STP600 identifies the signal source prior to making the conversion. This identification may be performed by OPC. Thus, the switch 615 is converted differently than the switch 620. For OPC for switch 615, the DPC for switch 650 is not translated. For the OPC of switch 620, the DPC of switch 650 is converted to the DPC of switch 640.

In addition, the signal information transmitted in reverse may be converted in a similar manner in the STP. For example, the information of switch 645 to switch 630 and switch 640 to switch 620 may translate their OPCs, representing switch 660 and switch 650, respectively. The switch 650 to switch 615 information does not require OPC to be converted.

The signal link in STP600 may be transcoded according to the information arriving. For example, signals from switch 650 to switch 615 need not be converted, while signals from switch 640 to switch 620 need to be converted in view of the new configuration. STP600 may be configured to convert OPCs of signal information arriving on signal link 745 into OPCs for switch 650. STP600 does not convert the OPC of signal information arriving on signal link 740. As can be seen, the conversion may be based on a variety of factors, such as signal link, OPC, DPC, CIC, SLS, and various combinations of these factors. Other factors may also be used with the present invention.

As described above, the signal network controls the signal network using the management information. An example of such information is transit restriction information. If link 750 between STP600 and switch 750 becomes congested, then signal routing management functions in STP600 will generate and transmit forwarding restriction information to alleviate the congestion condition of link 750. In the signal, the point code of switch 645 is used to define the blocked links (in the route label of its own route, the information still needs to be separate OPC and DPC). However, since other switches in the network have not been re-encoded, they cannot recognize the point code of switch 645. Thus, they cannot discern the blocked link and may continue to use it inadvertently. STP600 converts the point code in the process information defining the blocked link into a point code that is distinguishable by the signal point receiving the management information and can function appropriately on it.

Each signal point receiving the switching restriction information may be exclusively switched. This is accomplished using the DPC in the routing label of the management information to identify the received signal point for specialized conversion. For example, the point code defining the blocked link may belong to switch 655 for information sent to switch 625 and switch 660 for information sent to switch 630. In this case, the DPC in the route label is used to access a specialized translation of the point code defining the blocked link. In some cases, some management information targets may not require translation. E.g., transit restriction information sent to switch 615 regarding link 740. Resolution at the information source can be used to discern whether conversion is required.

Fig. 8 shows another embodiment of the present invention. Switch 810 is connected to STP830 and switch 820 is connected to STP 840. Signal processor 850 is coupled to STP830 and signal processor 860 is coupled to STP830 and STP 840. If switch 820 sends information to switch 810 through STP840, STP840 may convert DPC, representing the point code of signal processor 860. Thus, the information is passed to the signal processor 860. The information of signal processor 860 may have an OPC converted by STP840 to represent the OPC of switch 810. Thus, switch 820 does not need to be reprogrammed with the point code of signal processor 860.

In addition, signal processor 850 may function as the subscriber portion of STP 830. If switch 810 is to transmit a signal to switch 820, STP830 may pass the signal to signal processor 850 instead of switch 820. After processing the information, signal processor may transfer the information to switch 820 and STP830 may convert the OPC to that of switch 810. Information for switch 820 to switch 810 is handled in a similar manner. In this way, the signal processor 850 can process signals between switches in a manner that is transparent to the switches.

The present invention has many advantages. When the network configuration changes, the switches do not need to reprogram the signals with each other according to the new configuration. This avoids complex and time consuming work.

The invention can accommodate multiple switches since it acts on the signal as it enters MTP layer 3 processing. Signals directed to any one of the switches in the network through STP may be converted. Existing systems convert signals only after the MTP layer 3 routing function. The present invention allows a comprehensive and flexible system to function as an MTP layer 3 input.

Since the present invention does not rely on individual trunk identification, it can effectively satisfy the situation where all loads are moved between switches, or when multiple switch loads are consolidated onto one switch. In these cases, no separate trunk identification is required.

The invention enables the targeting of signal information according to the source of the information, so that a customized transformation can be performed for each source of the signal. Existing systems do not select a signal target that is consistent with the information source, but rather select from a separate trunk identification or target point code.

The invention may also be adapted to introduce a signal processor into the network. With the STP of the present invention, the signal processor may avoid the use of point codes altogether, or may have point codes that are transparent to the rest of the network.

The present invention provides an efficient, operable STP that can convert signals to accommodate changes in the fabric affecting several switches in a large network. The description and drawings provide embodiments of the invention, but the invention is not limited to these specific embodiments. It will be appreciated by those skilled in the art that there are numerous applications for the present invention which are made available in accordance with the following claims.

Claims (21)

1. A Signal Transfer Point (STP) capable of adding a signal transfer part (MTP) function to a plurality of signal information including a point code, the functions being a signal data link function, a signal link function and a signal network function, wherein the signal information belongs to the same protocol before and after conversion, the STP does not require a gateway function, the STP comprising:

first means for processing signal information using a signal data link function;

second means for processing the signal information using the signal link function;

third means for processing the signal information using the signal network function; and

converting means for converting at least some of the point codes in the signal information into different point codes, the signal information converted by the converting means including information received by the STP and information generated by the third means.

2. The STP of claim 1, wherein the conversion means comprises a first conversion means and a second conversion means, and the third means comprises an authentication function, a distribution function, a management function, a routing function, and the second conversion means; the second device is coupled to the first conversion device, the first conversion device is coupled to an authentication function, the authentication function is coupled to a distribution function and a routing function, the distribution function is coupled to a management function, the management function is coupled to the second conversion device, the second conversion device is coupled to the routing function, and the routing function is coupled to the second device.

3. The STP of claim 2, wherein the STP is coupled to a user portion that exchanges a portion of the signal information with the STP, the distribution function is coupled to the user portion, and the user portion is coupled to the second conversion device.

4. A Signal Transfer Point (STP) capable of adding a signal transfer part (MTP) function to a plurality of signal information including a point code, the functions being a signal data link function, a signal link function and a signal network function, the STP comprising:

first means for processing signal information using a signal data link function;

second means for processing the signal information using the signal link function;

third means for processing the signal information using the signal network function; and

converting means for converting at least some of the point codes in the signal information into different point codes, the converting means being located between the routing functions of the first means and the third means.

5. The STP of claim 4, wherein the means for converting is located between the second device and the third device.

6. The STP of claim 4, wherein the third means further comprises an authentication function, the means for converting being located within the authentication function.

7. The STP of claim 4, wherein the conversion is based in part on a point code originally included in the information.

8. The STP of claim 4, wherein the signal information further comprises a Circuit Identification Code (CIC), and the means for converting further converts the CIC.

9. A Signal Transfer Point (STP) capable of adding a signal transfer part (MTP) function to a plurality of signal information including a point code, the functions being a signal data link function, a signal link function and a signal network function, the STP comprising:

first means for processing signal information using a signal data link function;

second means for processing the signal information using the signal link function;

third means for processing the signal information using the signal network function; and

conversion means for converting at least some of the point codes in the signal information into different point codes, the conversion means selecting a target point code of the signal information corresponding to the original information associated with the signal information.

10. The STP of claim 9, wherein the information is passed onto a plurality of signal links, the signal links being divided into sets of links, the original information being the particular set of links over which the information was passed to the STP.

11. The STP of claim 9, wherein the original information is an origin point code (OPS).

12. A Signal Transfer Point (STP) capable of adding a signal transfer part (MTP) function to a plurality of signal information including a point code, the functions being a signal data link function, a signal link function and a signal network function, the STP being coupled to a subscriber part, the STP comprising:

first means for processing signal information using a signal data link function;

second means for processing the signal information using the signal link function;

third means for processing the signal information using the signal network function; and

conversion means for converting at least some of the point codes in the signal information into different point codes.

13. A telecommunications system, comprising:

a plurality of switches capable of generating signal information including a code identifying an information object;

the signal processor is positioned outside the switch;

a Signal Transfer Point (STP) capable of converting an object code identifying a specific switch into an object code identifying a signal processor and transmitting the signal information to the signal processor based on the converted code; and

signal links between the STP and the switch and between the STP and the signal processor can communicate signal information.

14. A telecommunications system, comprising:

a plurality of switches capable of generating signal information including a code identifying an information object;

the signal processor is positioned outside the switch;

a Signal Transfer Point (STP) capable of converting an object code identifying a specific switch into an object code identifying a signal processor and supplying the signal information to the signal processor through a layer 3 distribution function of an information transfer section, the transfer of the signal information to the signal processor being performed based on the converted code, the signal processor functioning as a subscriber section to the STP, and

the signal link between the STP and the switch is capable of transferring signal information.

15. A method of telecommunications signal transmission, comprising:

receiving signal information from a first signal point, the signal information including a code identifying the first signal point and a second signal point, and transmitting the signal information to a Signal Transfer Point (STP); and

at least part of the code is converted to a different code before the STP specifies the signal information for a particular target signal point.

16. The method of claim 15, wherein converting the code that identifies the second signal point.

17. The method of claim 15, wherein the code identifying the first signal point is translated.

18. The method of claim 15, wherein the converting is based on at least one code in the message.

19. The method of claim 15, wherein the switching is based on a particular link set on which the signal information is received.

20. The method of claim 15 wherein the first signal point is located in a first switch, the second signal point is located in a second switch, and the translated portion of the code identifies the signal point located in a third switch.

21. The method of claim 15, further comprising:

designating a signal link according to the converted code; and passing the signal information to the designated signal link.