摘要:
A packet transfer apparatus connects two networks of different protocols. The packet transfer apparatus, connected to a first communication network and a second communication network, performs the steps of: storing first destination correspondence information; receiving a packet of the first communication protocol; based on the first destination correspondence information, determining destination information of a packet of the second communication protocol corresponding to destination information of the received packet of the first communication protocol; generating the header of the packet of the second communication protocol, based on the determined destination information of the packet of the second communication protocol; converting the received one or more packets of the first communication protocol into one or more packets of the third communication protocol; and adding the generated header of the packet of the second communication protocol to the packets of the third communication protocol.
摘要:
An apparatus for replacing lost PSTN data in a packet network and for generating variable power white noise, includes a lost packet detection unit (402) for detecting lost data packets, a data processing unit (404) for producing in response a lost data output indicating when replacement data needed, data playout unit (408) or data replacement unit (406), each may be implemented as a variable power white noise generator (FIG. 3) to generate replacement data by reusing data stored in an extended playback buffer, and placing the re-used replacement data on an external network.
摘要:
Society of Motion Picture and Television Engineers (SMPTE) video data is separated into first data and second data. A first signal is formed based on the first data. A second signal is formed based on the second data. The first signal is transported via a first Optical Carrier 3 (OC-3) channel. The second signal is transported via a second OC-3 channel.
摘要:
An apparatus for and a method of generating pointers for identifying structure boundaries of data for leased lines such as T1/E1 in an asynchronous transfer mode (ATM) adaptation layer Type 1 (AAL1) through an ATM layer. The apparatus includes a control signal generating unit for receiving a sequence number signal and a start signal, thereby generating enable signals and control signals, a next-cycle boundary generating unit for generating a next-cycle boundary value, using a pointer value and a “Pointer_P” value adapted to store a sequence of ATM cells, a modulo calculating unit for calculating a modulo obtained by dividing the next-cycle boundary value received from the next-cycle boundary generating unit by an externally-received block size value, a current-cycle boundary generating unit for generating a current-cycle boundary value, using the next-cycle boundary value received from the next-cycle boundary generating unit, the modulo received from the modulo calculating unit, and the block size value; and the pointer calculating unit for generating a pointer value for determination of structure boundaries and a “Pointer_P” value, to be supplied to the next-cycle boundary generating unit, based on the current-cycle boundary value received from the current-cycle boundary generating unit.
摘要:
A telecommunications system comprising one or more cross-connects and a plurality of telephone exchanges wherein two or more of the telephone exchanges are arranged to communicate with each other via the one or more routers and an adapter for providing the telephone exchanges with a means of inter-communication via the one or more routers wherein the adapter converts traffic between packetised and non-packetised form.
摘要:
In a cell assembly and disassembly device having a cell disassembly unit (2) for disassembling the cell received from an ATM circuit interface, extracting data from the payload, distributing the data in plural time slots divided and multiplexed in time in frame period, and sending out to an STM circuit interface, the cell disassembly unit (2) comprises a fluctuation absorption buffer unit (11) provided in each time slot, and the data distributed in each time slot is once held in these buffers to absorb cell fluctuations, thereby suppressing both increase of total capacity of the memory for absorbing fluctuations and complication of memory control circuit, and reducing the cost.
摘要:
A common part sublayer (CPS) ATM adaptation device provides an interface between a narrow band network and a broad band network. The adaptation device is functionally partitioned to provide scheduling, prioritization and multiplexing of ingress traffic to the broadband network independently of the adaptation layer (AAL) type of that traffic. The device incorporating ingress and egress paths respectively to and from the broadband network. The egress path provides segregation and delineation of incoming data units on to respective external data ports, and the ingress path incorporates a common memory for payload storage whereby to perform multiplexing at both AAL and ATM layers.
摘要:
A method and apparatus are disclosed for ATM Adaptation Layer (AAL) staggered constant bit rate cell scheduling. Cells from a plurality of virtual circuits are scheduled. Each of the virtual circuits have a transmission characteristic and each of the plurality of virtual circuits are classified into one of a plurality of stagger groups based on similar transmission characteristics. For each frame synchronization, a cell is transmitted from a given virtual circuit until a predefined cell threshold is exceeded for the stagger group containing the given virtual circuit. A Cell Delay Variation of each of the virtual circuits will not exceed a given time interval. A scheduler can be allocated for each connection or for each period.
摘要:
Upon receipt of a synchronization request from the CPU, the AAL1 device of the act system causes its cell forming section to extract the allocation position information for the SAR-PDU payload about a particular time slot in the current frame and, via the synchronization information send/receive section, transfers the information to the AAL1 device of the standby system. The AAL1 device of the standby system causes its operation processing section to calculate the allocation position of a particular time slot in the next frame for the SAR-PDU payload based on the above allocation position information. The AAL1 device of the standby system starts allocation of the data of and following a particular time slot of the next frame to the SAR-PDU payload starting from the position indicated by the calculation result.
摘要:
The interworking of voice information in ATM cells is presently provided according to the standardizations of the ITU in the AAL1 adaption method. Specific properties of the voice information are taken into consideration therein. For interworking and transmission of other information data, further adaption methods such as, for example, the AAL5 method are provided. Here, the specific conditions of voice transmissions are not taken into consideration. In order to be able to implement the interworking and transmission of voice information according to the AAL5 standard as well, the AAL5 header is now inventively co-linked into the AAL5 information part of an ATM cell.