FI105982B - A method for verifying the operation of ISDN signaling channels - Google Patents

Description

1 105982

METHOD FOR VERIFYING ISDN SIGNALING CHANNELS

The present invention relates to a process and a method as described in the preamble of claim 1. A system as described in the preamble of claim 5, for securing the operation of the V5 interface established between the local exchange and the access node in connection with the initiation of the interface.

10 Open interfaces (V5.1 and V5.2) between a local exchange and a local area network or a wide area network element are specified in the ETS 300 324 and ETS 300 347 series standards of the European Telecommunications and Standard Institute. V5 interfaces allow for physically separate subscribers to be connected to a telephone exchange using a standard interface. In this application, the V5 interface specifically refers to the dynamic hub interface (V5.2) defined by the standard series ETS 300 347, which consists of one or more (1-16) PCM (Pulse Code Modulation) wires. One PCM cable has a total of 32 channels or time slots, each with a rate of 64 kbit / s or 2048 kbit / s in total. The V5.2 interface supports analog telephones operating in the public telephone network, digital, such as ISDN (Integrated Services Digital Network) basic and system interfaces, and other analog or digital semi-fixed terminal devices.

The 30 at the V5 interface passes through certain time slots by which the generated channel is called C-. channel, the protocols used to control the interface itself, as well as the calls made through the interface. The C-channel or the 64 35 kbit / s slot reserved for this purpose carries information which may be V5 control protocol, Link control protocol, Protection protocol, BCC-2 105982 protocol, or PSTN- signaling or ISDN signaling.

According to the above standards, the C-channel can be reserved for slots 16, 15 and / or 31 of the PCM cable, i.e. V5 interface lin-5kin, especially in the V5.2 interface, the system automatically generates C-channel critical protocols (Control, Link control, BCC). and Protection). Instead, the operator can place the PSTN signaling in the same channel as the critical protocols or in any other C channel as desired. In addition, the operator can allocate up to three signaling channels. varakanaviksi.

Backup channels are enabled by the time the link to which they were originally allocated fails. The V5.2 interface, which has more than one 2 Mbit / s connection, or link, defines as a primary link, or primary link, a connection whose physical C-channel in slot 16 carries the Control, Link control, BCC and Protection protocols. Further, the link 20 whose physical C channel in slot 16 carries only the Protection protocol is a secondary link, or a secondary link. The configuration of the V5 interface is reported with the Provision variant parameter. The provisioning variant parameter selects a particular configuration in connection with the interface curve 25, which indicates the layout of the protocols described above, i.e., the channel each protocol passes through the V5 interface.

Figure 2 shows a signal diagram illustrating a problem with the V5 interface boot-up procedure. During startup, certain protocols are executed, after which the interface is in Inservice mode. Figure 2 illustrates the sequence of starting protocols with the Protection protocol being started first. The Sys-35 tem management program block instructs the Protection protocol program block to start the Protection protocol. The same applies to all other s 105982 protocols. Lastly, the PSTN restart process is started. Under normal circumstances, after a PSTN restart, the V5 interface is in Inservice mode. However, as shown in Fig. 2, brochure-5, the PSTN restart process may be delayed * for many reasons known to those skilled in the art. The interruption of the restart is illustrated by arrow A in Figure 2. Similarly, during the connection start-up, a short interruption in the ISDN channel may occur as a result of thunder or other interference 10, resulting in ISDN channel backup. This is done because the Protection Protocol is already running and handles the protection it needs. Authentication is detected at both ends of the interface, where the original configuration according to the Provision variant parameter has been changed.

If the PSTN restart process does not complete at both ends of the interface, the end of the process that is not completed will start the restart. 20 The reboot also switches to the original configuration indicated by the Provision variant parameter, which results in a certified configuration at one end of the interface and the original configuration at the other end. Thus, upon initiation of the connection, the ISDN calls cannot be forwarded because the messages in the ISDN protocol do not pass through the V5 interface due to the crossing channels.

There is no mechanism defined in the standard for detecting the situation described above, although situation 30 prevents call forwarding from those ISDN subscribers configured to use said ISDN signaling channel.

The object of the present invention is to * eliminate the above problem. In particular, it is an object of the present invention to provide a method and system for ensuring that the V5 interface is properly started and that the post-start state is normal and correct, even if the interface is interrupted during startup.

As regards the features of the present invention, reference is made to the claims.

In the method according to the invention, in a V5 interface between at least two links between a local exchange and a subscriber network element, to ensure the operation of the ISDN signaling channels 10, upon initiation of the connection, a damaged signaling channel is verified from the first link to the second link. According to the invention, all standard authentication of ISDN signaling channels in the Protection Group 2 is blocked until the V5 interface is fully activated. This will ensure that after the V5 interface is turned on, both ends of the interface will operate according to the same configuration setting and no conflicts will occur.

The advantage of the present invention over the known tech-ankle is that it avoids spatial conflicts at the different ends of the connection due to the validation during the V5 interface start-up. Thanks to the invention, the V5 interface will continue to function normally even after a reboot, even if there are problems with the first boot 25.

If during start-up, the V5 interface on the local exchange side or on the subscriber network element side initiates ISDN signaling channel authentication, then the other end of the interface blocks 30 or does not accept the authentication if it has not yet started.

In the system of the invention for ensuring the operation of the ISDN signaling channels when the V5 interface is started up, there is a local exchange, a local area network element and a V5 interface arranged between the local exchange and the local area network element. The V5 interface includes 5,105,982 at least two links, whereby a corrupted ISDN signal output channel can be secured from the first link to the second link according to the interface configuration settings. According to the invention, the system includes means to prevent all ISDN signaling channels from being authenticated until the V5 interface is fully activated, thereby ensuring that after the V5 interface is activated, both ends of the interface operate according to the same initially set configuration settings.

In a preferred embodiment of the system, it comprises means for monitoring the start-up phase of the connection. Preferably, the means are provided at both ends of the interface, i.e. the local exchange and the access node, since either side can initiate backup, which must be prevented if the connection is not fully started.

In the following, the invention will be described by way of a preferred embodiment, with reference to the accompanying drawings, in which Figs. 1a-Id illustrate a possible conflict of start-up phase of the V5 interface; and Figure 2 shows a signaling diagram. The figures schematically show a system according to the invention comprising a local exchange LE and a local area network element AN. Between them is provided a V5 interface V5 which includes at least two links L1 and L2. In addition, at each end of the V5 interface V5, i.e. the local exchange LE and the space-30 network element, there are means 1 for blocking the authentication of all ISDN signaling channels and means 2 for monitoring the start-up phase of the interface.

Fig. 1a shows a normal, original * situation in which the link LI is configured with an ISDN

35 broadcast channels. Link L2 has a backup channel for which the ISDN signaling channel can be certified. Figure Ib shows the situation after the failure, with the link L1

ί 105982 is corrupt and the ISDN signaling channel is being verified for link L2.

If this is a start-up phase and the LE side of the local exchange has not yet started, the situation is similar to that shown in Figures le and Id. The subscriber network element AN maintains the channel con- figuration such that the ISDN signaling channel passes through link L2, FIG. In the opinion of the local exchange LE, the ISDN signaling channel passes through the link L1, 10 because the local exchange did not recognize the channel validation because it believed it was in the process of being booted, which caused it to restart in its original configuration due to interference.

The situation described above can be effectively prevented by means of means 1, 2 for monitoring the start-up phase of the local exchange and the access node. In practice, monitoring of connection initiation and channel authentication is accomplished by instructing the System management program block to Pro-20 tection program block to block all authentication of channels belonging to Pro tection Group 2 until both ends of the interface are triggered.

The invention is not limited to the above embodiments only, but many modifications are possible within the scope of the inventive idea defined by the claims.

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Claims (9)

A method of forming a V5 interface between a local exchange, (LE) and a subscriber network element (AN), to which at least two links (L), for securing the function of ISDN signaling channels in connection with the start of the V5 interface, wherein a damaged signaling channel from a first link (L1) to a second link (L2) is secured, it can be characterized that all the fuses of the ISDN signaling channels are prevented until the V5 interface has started completely, it is ensured that after the V5 interface has started, the interface ends of the interface operate according to the same composition setting. 15 2. A method according to claim 1, characterized in that if during the startup the part of the V5 interface is against the local exchange (LE) or the part which is against the subscriber network element (AN), the securing of the ISDN signaling channels begins, say 20. prevents the part of the V5 interface which is towards the other end of the fuse, if it is of the intention that it has not yet started. Method according to claim 1 or 2, characterized in that the interface composition parameter is a V5 interface Provision-Variant parameter according to the V5 specifications. 4. System for securing the function of ISDN signaling channels in connection with the start of a V5 interface, to which system belongs a local exchange (LE), a subscriber network element (AN) and a V5 interface, which is arranged between the local exchange:. and the subscriber network element for joining them and associated with at least two links (L), in which system a damaged signaling channel from a first link (LI) to a second link (L2) is secured, characterized in that to the system hears means (1) for obstructing the fuses of all ISDN signaling channels until the V5 interface has fully started, ensuring that after the V5 interface both ends of the interface operate according to the same configuration setting. The system according to claim 4, characterized in that the system belongs to means (2) for observing the start-up phase of the interface, in which case during the startup the part of the V5 interface which is against the local exchange (LE) or the part which is against the subscriber network element (AN) starts securing the ISDN signaling channels as hindered by the means for observing the interface start-up phase, securing the portion which is towards the other end of the V5 interface, if it has not yet started in the normal operating state. Method according to claim 4 or 5, characterized in that the interface composition parameter is a V5 interface Provision-Variant parameter according to the V5 specifications. System according to any of claims 4-6, characterized in that the V5 interface is a V5.2 interface according to the standard series ETS 300 347. 25