Abstract: The invention concerns a method of managing data packets originating from data frames, the packets being presented to buffer (40) prior to processing. When a packet corresponding to the start of a frame is presented to the buffer stage, it is determined whether the filling level of the buffer (40) exceeds a first predetermined filling threshold (42) corresponding to a state of congestion and, if such is the case, this packet and all packets belonging to that same frame are systematically discarded before the buffer. The frames can e.g. originate from AAL2 connections, and each constitute a respective ATMS adaptation layer service data unit (AAL2 SDU), in which case the packets are common part sublayer (CPS) packets, and the buffer (40) stores the CPS packets before the latter are multiplexed into asynchronous transfer mode (ATM) cells. The invention also relates to an apparatus for implementing the above method.

Abstract: Method and device provide for the encapsulation of control information in a real-time data stream. In one embodiment a method of encapsulating data in an information frame is provided. This information frame has a payload portion and a trailer portion wherein the trailer portion is designated for control data and the payload portion is designated for real-time data. In use control data is inserted into the payload portion of the information frame and an extension bit is used to signify the presence of control data in the payload portion of the information frame. The information frame is then transmited over a virtual circuit.

Abstract: Sample packets (S1-Sn) are formed from an input signal (1), there being a sample period (P1-Pn) related to each sample packet. The sample packets are inserted into a packet network (4) and transmitted to a recipient. The information content of the input signal per time unit (BR) is monitored and the information content of each sample packet (S1-Sn) is kept substantially constant on the basis of this information by controlling the duration of the sample period (P1-Pn) of the sample packets. Information on the duration of the sample period (P1-Pn) is transmitted to the recipient in the packet network packet. The packets (4) are received in the receiver and sample packets (S1-Sn) are separated from them and supplied to a decoder (7). Information on the duration of the sample period (P1-Pn) is also separated and supplied to the decoder (7), which uses it as the playing time of the restored output signal (8).

Abstract: Collisions caused by simultaneous allocation of the same channel identifier (CID) to two AAL2 connections over an ATM virtual channel connection between first and second nodes in an asynchronous network are avoided by the use of status records. Each node maintains a record of currently assigned CIDs and compares the CIDs of incoming connection requests with that record. Where the CID of such an incoming request is found to have been assigned, a message is returned to the request originator refusing the connection request. Preferably a set of CIDs is assigned to one node so that, in the event of a potential collision, that node seizes the connection.

Abstract: A method and apparatus are provided to remove dataless TDM frames when transporting private line traffic over an ATM network. A number of TDM frames comprising a TDM private line circuit are received, and it is determined if a TDM frame contains data. The determination may be based on, for example, the detection of one or more frame delimiters, such as by comparing information in the TDM frame with a pre-determined frame delimiter pattern. Information from the TDM frame is placed into an ATM cell only when the TDM frame contains data. An indication that a TDM frame has not been placed into an ATM cell is conveyed in the AAL2 headers.

Abstract: This invention provides a communication network with a method and apparatus for interrupting the transmission of an existing stream of data to insert interrupting packets which may have a higher priority than the existing data stream. The interrupting packets are inserted in the data stream by making use of unused pointer values in common transmission schemes known as the Data Over Cable Service Interchange Specification (DOCSIS) or the Asynchronous Transfer Mode (ATM) adaptation layer 2 (AAL2) format of the International Telecommunications Union (ITU) recommendation I363.2. Advantageously, the scheduling of packets is significantly simplified and the packet jitter is better controlled which results in a significant improvement in transmission performance.

Abstract: The invention is a system for providing virtual connections through an ATM interworking multiplexer on a call-by-call basis. A signaling processor receives signaling for a call and selects the virtual connection for the call. The signaling processor generates control messages that identify the selection and transfers the control messages to the ATM interworking multiplexer that accepted the access connection for the call. The multiplexer converts user information from the access connection into ATM cells for transmission over the virtual connection in accord with the control messages.

Abstract: In a communication system a multimedia signal is encoded in an encoder (1) and subsequently transmitted over a packet switched network (4) to a terminal (6). The terminal (6) comprises a receiver (8) whose output is connected to a receive buffer (210). The output of the receive buffer (210) is applied to the presentation means (214) which comprises a decoder (216) and a presentation device (218).

Abstract: A voice path direct memory access (DMA)-based packet generation mechanism writes digitally encoded voice samples directly into prescribed subportions of a preallocated portion of random access memory, to avoid interrupting a main processor for the purpose. A pointer to a respective buffer space subportion is presented to a protocol stack, so that one or more overhead bytes for the stored voice samples can be generated and written into adjacent address space of the preallocated portion of random access memory. The contents of the preallocated memory space are then serialized out for transmission to a destination receiver.

Abstract: Data stream transfer apparatus for receiving a data stream of data cells at variable time intervals and transmitting data frames at predetermined time intervals, including a receiving apparatus, a buffer memory, a data transfer interface, a central processing unit (CPU), and a memory access unit. The receiving apparatus receives the data cells and stores them in the buffer memory. The data transfer interface transfers data frames out of the apparatus at the predetermined time intervals and generates an indication that the data frame has been transferred. The memory access unit receives data defining a location of a data frame in the buffer memory, accesses the buffer memory to retrieve that data frame and transmits that data frame to the data transfer interface. The CPU, upon receiving the indication, determines a time for transfer of a subsequent data frame, and upon reaching that time, transmits to the memory access unit the location of the subsequent frame in the buffer memory.

Abstract: An incoming logical leg and an outgoing logical leg for a received call are defined using allocated identifications, and a switching operation for the received call is controlled on the basis of the incoming logical leg and the outgoing logical leg. Thus, physical resources of the switching network element are hidden from the visibility of the application layer and there is no need for different versions of applications in different switching techniques. Through switch connections through the switching network element thus consist of several subconnections terminated at service points where the payload and traffic parameters of the connection will change. The logical legs will change with the mobility of the user. The logical legs are managed by a leg control unit which controls the reservation of the service resources from corresponding resource management units and the cross-connection handling between the service points.

Abstract: A data reception unit for receiving a plurality of data streams over a data chanel. The data streams are received as amounts of data, each amount of data comprising a data portion including data from a data stream and an identity portion identifying that data stream. The data reception unit comprises a data stream memory comprising a plurality of data stream storage areas and a reserve buffer, a first storage information memory for holding first storage information, a processing unit, and a data storage controller. The data storage controller, for each received amount of data, receives the identity portion of the amount of data and performs a storage operation-based on the identity portion.

Abstract: A Public Switched Broadband Network (PSBN) and method of operation permits high-speed, broadband, simultaneous, bi-directional data transfer over the infrastructure of conventional public switched telephone network. In addition, the PSBN provides a high-speed broadband public switched network that utilizes a common data transmission protocol from a broadband or internet service provider, through inter-office facilities, through a serving central office and to the end user, thereby providing a substantially “flat” network and reducing latency problems associated with protocol conversions. Still further, the PSBN provides expanded capacity throughout the network without requiring the implementation of new infrastructure.

Abstract: Provided is a cell exchanging device which realizes switching of an AAL2 connection level using an existing ATM switch, thus preventing deterioration of a transfer quality of other ATM cells. In an input-side ATM line corresponding section, provided are an ATM cell demultiplexing section 113-I-1 for extracting and separating only an AAL2 cell from an ATM cell, an AAL2 DMX 113-I-2 for converting from the AAL2 cell to an AAL2 partial fill cell, and an ATM cell multiplexing section 113-I-4 for multiplexing and packing the ALL2 partial fill cell and the ATM cell other than AAL2. Before entering to the ATM switch, a priority order of each ATM cell is determined based on class information presented in the ATM line corresponding section, and reading-out from the ATM cell multiplexing section is controlled.

Abstract: A method for mapping a plurality of minicells into a channel structure is disclosed. The channel structure has a plurality of multi-frames with each multi-frame having a plurality of time slots. A start octet is inserted in a first time slot of each multi-frame and the sequence number within the start octet is used to count the number of multi-frames.

Abstract: A single group of signals interfaces a computer system to either an analog display or a digital display. A video signal in digital format and a video signal in analog format are both supplied to a circuit that multiplexes the digital signal and the analog signal, generating an appropriate output signal for the display, either analog or digital, that is coupled to the computer system. In one example, the signal connector interfaces the computer system to either an analog CRT display or a digital FPD display. The multiplexer multiplexes the analog signal and the digital signal supplied by the computer system and generates an output signal that is suitable for the CRT display or the FPD display, depending on the type of display coupled to the computer system.

Abstract: A method of multiplexing a plurality of virtual channel connections into a single channel is disclosed. Each of the virtual channel connections is made up of a plurality of minicells within an AAL2 protocol. The user to user indication field of the minicell is used in addition to the connection identifier to identify each of the virtual channel connections. A method is also disclosed for demultiplexing virtual channel connections from a single channel into AAL2 minicells.

Abstract: A transport stream receiver de-encapsulates content packets from received network frames and transmits a transport stream carrying the selected content packets.

Abstract: An AAL2 packet exchange device is placed in front of an ATM switch for executing CPS packet re-multiplexing into ATM cells. The AAL2 packet exchange device extracts CPS-PDUs (Common Part Sublayer-Protocol Data Units) from ATM cells which are supplied from input ATM lines, extracts CPS packets from the CPS-PDUs, alters CIDs (Channel IDentifiers) of the CPS packets if necessary so that CID collision will not occur between CPS packets supplied from different sources to be outputted to the same output ATM connection, multiplexes the CPS packets to be outputted to the same output ATM connection in ATM cells of the same output ATM connection. The CID alteration is executed by referring to a path setting table which stores each correspondence between a first internal address for discriminating between input ATM connections, an input CID, a second internal address for discriminating between output ATM connections, and an output CID.

Abstract: A compressively-encoding-resultant video signal resulting from compressively encoding a video signal, a first compressively-encoding-resultant audio signal resulting from compressively encoding a first audio signal having a synchronized relation with the video signal, a reference clock information signal relating to synchronization between the compressively-encoding-resultant video signal and the first compressively-encoding-resultant audio signal, and an indication timing information signal designating an indication timing of the video signal are multiplexed to get an AV multiplexing-resultant signal. A second audio signal is compressively encoded to get a second compressively-encoding-resultant audio signal. A sound-production-timing information signal is added to the second compressively-encoding-resultant audio signal to get a substitution playback audio signal.

Abstract: Embodiments for communicating between a headend and multiple subscriber units in an interactive video entertainment network are described. The headend includes multiple ATM switch ports connected for data communications through individual communications channels. In one aspect, an assignment of an individual subscriber unit to one or more communications channels is requested. Next, relative available capacities of the communications channels are assessed. The individual subscriber unit is then assigned to one or more communications channels and corresponding ATM switch ports based on the assessed capacities of the communications channels. The individual subscriber unit is set to communicate with the headend over its assigned communications channels. An ATM virtual connection between the individual subscriber unit and the headend is then established through the communications channels and corresponding ATM switch ports assigned to the individual subscriber unit.

Abstract: In a device and method for minimizing transmission delay of low-rate data such as voice data and for enhancing the transmission efficiency in multiplexed data communication using AAL type 2 protocol the SSCS of the high-rate data side of an AAL type 2 converter is responsible for addition and elimination of a dummy code field, error correction, and division and reassembly of data unit. A dummy code field and restorative code field are attached to a user data unit which is supplied from the higher layer in a source device, whereby a data unit is prepared. The data unit is then divided into segments 1 to m of a fixed-length, 45 octets. Successive code fields 1 to m are attached to the segments 1 to m, whereby data blocks 1 to m are prepared. The data blocks 1 to m are successively transferred to the AAL-2 converter. In a destination device, from the data blocks 1 to m, the user data unit is reassembled.

Abstract: A musical tone data communications system having a unit for generating MIDI data of a musical performance by a player, a unit for transmitting the generated MIDI data over a communications network and a unit for receiving the transmitted MIDI data and reproducing musical tones corresponding to the MIDI data in real time.

Abstract: Variable-rate encoding apparatus operative to receive data and process the data for transmission through an asynchronous transfer mode network. A processor determines a degree of circuit congestion associated with at least one virtual circuit of the network. A variable-rate encoder encodes the received data so as to provide encoded data packets to the at least one virtual circuit at a rate that is selected responsive to the degree of circuit congestion. An ambiguity resolving field is preferably added to at least some of the data packets so as to resolve ambiguity regarding encoding rate.

Abstract: In a telecommunications network, an ATM Adaptation Layer 2 (AAL2) signaling protocol is employed independent of the signaling bearer service being used in transport signaling messages to and from various network entities, such as mobile switching centers, radio network controllers and cell base stations in, for example, a mobile telecommunications network. This is achieved by dividing the functionality of the AAL2 signaling protocol into a number of functional sublayers including an AAL2 Signaling Common Part (CAP), a Bearer Coordination Part (BCP) and a Bearer Adaptor Part (BAP), wherein the BAP adjusts incoming and outgoing messages so that they are compatible with the AAL2 signaling protocol or the underlying signaling bearer service respectively.

Abstract: A national broadband network is based on fiber optic technology and scaled to cover a wide area, such as the contiguous lower United States. The network provides a high data rate interface for each subscriber and supports all the functions of the current telephone, Internet, and cable TV networks, with sufficient excess capacity to support future applications. Signals from several thousand subscribers are multiplexed on a single fiber pair connected to an intelligent switching center. Telephone central offices (COs) become multiplexing centers rather than switching centers, and the number of switching centers required to cover the nation is greatly reduced. Approximately 500 switching centers are interconnected by an optical backbone. Physical layer connections are established through the backbone between each pair of switching centers. Multiple ATM and/or STM connections are carried within each of these physical layer connections.

Abstract: The apparatus for converting a first data stream supplied from a first buffer for accumulating the first data stream into a second data stream, and supplying the second data stream to a second buffer for accumulating the second data stream, is provided. The first data stream includes a plurality of first data groups each including significant data. Further, the first data stream includes a plurality of time values each indicating a point of time corresponding to a position of respective one of the plurality of first data groups within the first data stream.

Abstract: A system and method for synchronizing variable bit rate traffic between a source and destination in an Asynchronous Transfer Mode (ATM) network. The method includes designating a variable bit rate ATM Adaptation Layer (AAL) protocol to define ATM cell traffic flow from the source to the destination. A synchronous residual timestamp (SRTS) value indicative of the timing of a source clocking function is encoded and transmitted with an ATM cell using a variable bit rate AAL, such as AAL2 or AAL5. The ATM cells and associated SRTS values are received and decoded at the destination ATM interface, and the destination clock is synchronized with the source clock by modifying the destination clock according to the SRTS values.

Abstract: A broadband communication system and method utilizing an asynchronous transfer mode core switch is provided. A plurality of central offices are connected to the asynchronous transfer mode network. An asynchronous transfer mode core switch connects to the asynchronous transfer mode network. The core switch is connected to each central office to allow an information provider, such as a video or data provider, to communicate with the plurality of central offices through the core switch. That is, the core switch provides numerous advantages, including a defined point of entry into the asynchronous transfer mode network.

Abstract: A method and system supports multilevel QoS (Quality of Service) in transferring a plurality of packets from a local peer entity to a remote peer entity of a communication system, such as a mobile environment using AAL2. During AAL2 Negotiation Procedures (ANP), QoS requirement of each user is obtained either from the user or a computed based on the call setup and is recorded in a ANP memory. After a successful call request negotiation and after a corresponding packet is received by a AAL2 service module, the packet's QoS recorded in the memory is checked. Based on the QoS, the packet is placed into a queue of the AAL2 service module with the same QoS such that a plurality of packets having the same QoS are grouped into the same queue. The packets are transferred from the local peer entity to the remote peer entity based on different QoS requirements.

Abstract: An intelligent switch for routing data through a network fabric in accordance with a requested quality of service (QoS), comprising: a processor; a network interface coupled to the processor and the network fabric; and means for predicting load and redistributing traffic to deliver the data at the requested QoS.

Abstract: In a node of a data communications network, connection handling functionality is distributed among plural processors of a processor cluster. Infrastructure data for the connection handling functionality is distributed among the plural processors of the processor cluster; resource handling data is partitioned among the plural processors of the processor cluster; and connection data is created on a selected processor of the processor cluster when an on demand connection is established at the selected processor. For network-wide connections, a predistributor of the node routes signaling messages incoming to the node to an appropriate processor of the processor cluster.

Abstract: In order to interoperate with all types of transport networks working with packets of constant size, an encapsulation method is proposed to adapt multiplexed data, organized in successive, individually accessible portions, to these networks. Said data are segmented to fit the size of the network packets, and, for matching the last segment of said data to said constant size, a padding step is provided for adding a padding packet to each last segment.

Abstract: An interface arrangement provides interworking between packet (IP), time division multiplex (TDM) and asynchronous (ATM) networks, and incorporates a TDM framer providing an interface to the TDM network, a packet framer providing an interface to the packet network, and ATM adaptation function providing an interface to the ATM network. The ATM adaptation function comprises a set or suite of integrated circuit devices, the devices being partitioned by AAL functions into a first device set arranged to perform a common part sublayer function and a second device set arranged to perform service specific sublayer functions. The composition and nature of the device sets can be chosen to match the traffic types and quality of service requirements.

Abstract: A cell switching method and system are disclosed that divide an input ATM cell into ATM adaptation layer (AAL) 2-type common part sublayer (CPS) packets. The divided CPS packets are stored in different first storage areas, in accordance with virtual paths/virtual channels (VPs/VCs) of the respective CPS packets, and identifiers of the first storage areas are also stored. The stored CPS packets are read in the order of the stored first identifiers. Thereafter, the read CPS packets are stored in second storage areas, in accordance with respective CIDs, and second identifiers of the second storage areas are stored. The CPS packets stored in the second storage areas are read in the order of the stored second identifiers and multiplexed to generate ATM cells.

Abstract: A monitoring network is able to provide surveillance of IP phone calls, which span plural backbone networks, which may embody different transmission techniques. An agent connected through a monitor center to one backbone network enters a request for surveillance (i.e. wiretapping) of a particular network connected to another backbone network. A WatchDog program is associated with each backbone network. These WatchDogs all communicate with other watchdogs associated with other backbone networks. All these watchdogs interact with one another to set up the surveillance connections. The watchdog of the requester's backbone network receives the surveillance request and flows/transmits the request to a watchdog function of the terminating backbone network of the specific caller to be monitored establishing a point-to-point connection, through as many backbone networks as needed.

Abstract: A TS parser and a PES parser restructure one ES or a plurality of ESs from a TS packet and a video PID, and a PES packet and a video PID, and output them. The TS parser and the PES parser send the restructured ES(s) to a separate ES buffer. A decoder section reads a certain ES from the separate ES buffer according to an instruction from a control interface section and decodes it in units of frames or fields. A VRAM interface section classifies the image data decoded by the decoder section by program and stores them in a VRAM. An output format selector section selects a certain image data from the image data stored in the VRAM according to an instruction from the control interface section and outputs it.

Abstract: A first header converting section outputs, when partial fill cells are inputted to the first header converting section the partial fill cells, while converting a VPI of each of the partial fill cells into a value that is a unit of a multiplexing process at a short cell multiplexing section and converting a VCI of each of the partial fill cells into a value to be a CID which is to be stored in a short cell at the short cell multiplexing section. The short cell multiplexing section receives a plurality of the partial fill cells from the first header converting section to multiplex a plurality of the short cells within the partial fill cells for every VPI of the partial fill cells, and produces an AAL Type 2 cell in which the VCIs of the partial fill cells are stored as CIDs and the VPIs of the partial fill cells are stored as VCIs.

Abstract: A voice packet processor for use with voice applications employing a fast pattern processor (FPP) and a routing switch processor (RSP) that receive and transmit protocol data units (PDUs) and a method of operation thereof. In one embodiment, the voice packet processor includes (1) a voice packet controller (VPC) configured to receive the PDUs from the FPP and queue the PDUs for processing, (2) a voice packet parser configured to receive the PDUs that are ATM adaptation layer 2 (AAL2) cells containing voice data from the VPC, parse the AAL2 cells into at least one Common Part Sublayer (CPS) packet and transmit the at least one CPS packet to the RSP, and (3) a voice packet assembler configured to receive the PDUs that are CPS packets from the VPC, assemble the CPS packets into at least one AAL2 Cell and transmit the at least one AAL2 cell to the RSP.

Abstract: A method of switching partial minicells in an AAL2 switching network without the need for re-assembly of the partial minicells at intermediate nodes. Identification of each remainder partial minicell (432) is accomplished using an 8-bit channel identifier (450), a double octet identifier (950) or a triple octet identifier (1050) depending on traffic requirements. Each partial minicell is immediately transmitted based upon the identification code attached to each partial minicell.

Abstract: An asynchronous transfer mode (ATM) system having an interleaver of 8 bit parallel cell units includes n ATM cell header buffer for storing an ATM cell header into a cell header buffer or outputting data by 1 bit at a buffer according to a control signal output from a write controller or a read controller, a write controller to separate and store a cell header and a payload, read controller to sequentially the mixed output data from the interleaver memory, an interleaver memory for using payload data of ATM cells . . . , and a multiplexor for multiplexing 12 byte data output from the interleaver memory, wherein a 8 bit interleaver is directly added to the conventional ATM processing method since all ATM cells are to be processed by 8 bit parallel unit, and all interleaving process may be performed in parallel without any serial/parallel converting circuit, thereby achieving a device which is proper for low speed wireless environment.

Abstract: Communicative services are transported over a TDMA or TDM access network by packetising the services into minicells which minicells are transported within minislots created by subdivision of the TDM time slots. For low bit rate communicative services only, mini-slots are allocated periodically rather than in the blocks that are allocated to high bit rate services. The packetisation delay inherent within the transport layer can be significantly reduced for these low bit rate services.

Abstract: Disclosed is an asynchronous transfer mode relating to a cell switching method, a cell format converter thereof, and a switching system thereof which are proper for switching an AAL2 ATM cell and an AAL5 ATM cell using an AAL2/AAL5 converter and an AAL5/AAL2 converter. Namely, AAL2 traffic may be switched at an AAL level using the AAL2/AAL5 and AAL5/AAL2 converters, so as to increase a system efficiency and provide a flexible interface between AAL2 and AAL5 protocol.

Abstract: A cell switching method and system are disclosed that divide an input ATM cell into ATM adaptation layer (AAL) 2-type common part sublayer (CPS) packets. The divided CPS packets are stored in different first storage areas, in accordance with virtual paths/virtual channels (VPs/VCs) of the respective CPS packets, and identifiers of the first storage areas are also stored. The stored CPS packets are read in the order of the stored first identifiers. Thereafter, the read CPS packets are stored in second storage areas, in accordance with respective CIDs, and second identifiers of the second storage areas are stored. The CPS packets stored in the second storage areas are read in the order of the stored second identifiers and multiplexed to generate ATM cells.

Abstract: An apparatus and a method of communicating a set of user data in an ATM network-based mobile communication system are disclosed. To transmit the set of user data, N internal AAL packets are generated by adding an internal AAL packet header to each of N data subsets of an original set of user data. The internal AAL packet header includes a sequence number of each data subset. Next, one or more internal AAL cells are generated by multiplexing the internal AAL packets. Then, the original set of user data is restored by demultiplexing the internal AAL packets, included in the internal AAL cells. Thereafter, M AAL2 packets are generated by adding an AAL2 packet header to each of M data subsets of the restored set of user data. And finally, one or more AAL2 cells are generated by multiplexing the AAL2 packets. As a result, the set of user data is transmitted in the system in a much more efficient manner. Therefore, the data traffic rate in each part of the system is greatly enhanced.

Abstract: An apparatus and method provide non-intrusive in-service testing of audio/video synchronization testing without using traditional audio marker tones. The network includes an A/V synchronous test signal generator which injects video and audio markers into the video and audio non-intrusively and routes the two signals into a switch where they are switched into a channel for encoding and transmission via the ATM network. At the distant end the signal is decoded and routed by a switch into the A/V test generator and measurement set where the markers are detected and the A/V skew calculated, after which the audio and video are routed to the subscriber. The A/V test set signal generator includes a Video Blanking Interval (VBI) test signal generator and a white noise generator, the former injecting a marker into the video signal and the later injecting an audio marker into the audio signal.

Abstract: A method is provided for transporting variable length packets such as IP packets and fixed length packets of length N, such as MPEG video packets, in standard digital transmission frames such as DS-3 frames. Each frame comprises a plurality P of sections having a fixed length M which is greater than N. A fixed length trailer is added to each of the variable length packets. Each variable length packet with the added trailer is segmented into an integer number of segmented packets of length N. Padding bits are added if necessary to provide the integer number of segmented packets. A header and trailer are added to each of the segmented packets and fixed length packets to expand them into an expanded packet length M. P of the expanded packets are combined into a frame for transmission.

Abstract: To ensure that appropriate resources are available in a network when AAL Type 2 connections are to be established, the network is divided into resource domains (RD—1, RD—2, RD—3, RD—4), and each resource domain is provided with a prediction connection admission control unit (p-CAC—1, p-CAC—2, p-CAC—3, p-CAC—4) which comprises information about available resources through its own resource domain as well as information about available resources for connections through the other resource domains of the network.

Abstract: In a telecommunications system, in which a connection comprises a part with an interworking function at both ends, a channel is allocated to the connection between the interworking functions. The required channel capabilities may vary during the connection, whereby the channel capabilites should be changed. When the first interworking function detects that a channel capability must be changed, a first message, which indicates the desired capability change, is transmitted (2-1) to the second interworking function; and the channel capability is changed (2-3, 2-5) into the desired one at both ends of the part.