KR20040055010A - Processing apparatus and method for RTP packet in IP-PABX - Google Patents

Abstract

PURPOSE: An RTP(Real Time Protocol) packet processing apparatus in an Internet phone exchange and a method therefor are provided to process RTP data in a TDM format and send it to a TDM interface without going through a central processor. CONSTITUTION: A LAN interface(220) interfaces with a LAN(210) and receives an RTP packet including a packet having information and voice. An RTP packet processor(230) analyzes and stores data inputted through the LAN interface(220) and transfers it to a TDM interface(250) or to a central processor(240). The central processor(240) transfers information to the RTP packet processor(230) so that the RTP packet and a TDM packet can be mutually converted.

Description

Processing apparatus and method for RTP packet in IP-PABX}

The present invention relates to an Internet telephone exchange (IP-PABX), in particular, to process RTP (Real Time Protocol) data in a TDM format, so that the RTP packet processing in the Internet telephone exchange can be sent to the TDM interface without passing through the central processing unit. An apparatus and method are provided.

1 is a block diagram showing a data processing apparatus in a conventional Internet telephone exchange.

Referring to FIG. 1, a LAN interface 120 for interfacing with a LAN 110 to receive a packet with information and an RTP packet including real voice and data input through the LAN interface 120 are provided. A central processing unit (CPU) 130 for analyzing and transmitting the RTP data to the digital signal processor 140 and sending the data to the system highway through a connection with a time division multiplexing (TDM) interface 150; ROM (131) and SDRAM (SDRAM) 132.

The data processing apparatus of the Internet telephone exchange as described above will be described with reference to FIG. 1.

Referring to FIG. 1, the central processing unit 130 receives data from the LAN 110 through the LAN interface 120 and analyzes the received data. The data at this time is a packet with information and a packet (RTP) containing actual voice.

In this case, when the received data is the RTP data, the data is transmitted to the external digital signal processor 140. The digital signal processor 140 stores and processes the RTP data to process the voice portion of the RTP packet, thereby processing the central processing unit ( 130).

That is, the central processing unit analyzes the packet received from the LAN interface 120, extracts the voice data, and sends it to the digital signal processor 140 to be converted into TDM data. That is, the digital signal processor 140 is responsible for processing the voice portion of the packet corresponding to the actual voice.

The central processing unit 130 sends the RTP packet to a system highway (ie, a system bus) through a connection with the TDM interface 150.

Here, the packet data coming through the LAN interface 120 enters a large amount of data (for example, 20 ms of data) at a moment, and thus, a buffer is stored in the digital signal processor 140.

However, in the related art, since the central processing unit processes and manages all data, a large load is applied, and thus a high function central processing unit and a digital signal processor are required.

The present invention has been made to solve the above problems, and if the corresponding data is an RTP packet by analyzing the data received through the LAN, after processing in the RTP packet processing unit, it can be connected to the TDM interface and transmitted to the system highway On the other hand, it is an object of the present invention to provide an apparatus and method for processing an RTP packet in an Internet telephone switchboard so that the data can be delivered to the central processing unit if the corresponding data is a packet required by the central processing unit.

It is another object of the present invention to provide an apparatus and method for processing an RTP packet in an Internet telephone switch having a memory inside the RTP packet processing unit so that the RTP packet can be stored and processed to be read from the TDM interface.

1 is a block diagram showing an apparatus for processing a RTP packet in a conventional Internet telephone exchange.

2 is a block diagram illustrating an apparatus for processing an RTP packet in an Internet telephone exchange according to an exemplary embodiment of the present invention.

3 is a table configuration diagram of the memory of FIG. 2.

4 is a flowchart illustrating a method of processing an RTP packet according to an exemplary embodiment of the present invention.

<Description of the symbols for the main parts of the drawings>

210 ... LAN 220 ... LAN Interface

230 ... RTP packet processor 231 ... memory

240 ... central processing unit 250 ... TDM interface

RTP packet processing apparatus in the Internet telephone exchange according to the present invention for achieving the above object,

A LAN interface for receiving a packet having information from the LAN and an RTP packet containing voice information;

A TDM interface for requesting channel numbers in channel order and sending them to the system highway;

An RTP packet processing unit for analyzing and storing data input through the LAN interface and converting the RTP packet into a TDM format if the RTP packet is transmitted to the TDM interface;

The RTP packet processing unit includes a central processing unit for recording connection information in the RTP packet processing unit so that the RTP packet and the TDM packet can be mutually converted.

Preferably, the RTP packet processing unit includes a memory therein, analyzes data coming from a LAN interface, converts the data into a TDM format using an internal memory in the case of an RTP packet, and transfers the data to a TDM interface, and not the RTP packet. Characterized in that the transfer to the central processing unit.

In addition, the RTP packet processing method in the Internet telephone exchange according to the present invention, the central processing unit recording the connection information received via the system highway in the memory of the RTP packet processing unit; Checking, by the RTP packet processor, a receiving port of the RTP packet from the LAN interface, determining a recording area of the internal memory, and checking valid bits; Storing data in a memory area indicated by an input pointer value when the valid bit is 1, updating an input pointer and a packet storage time, and transferring the data to a central processing unit when the valid bit is not 1; Thereafter, upon receiving the data request together with the corresponding channel number from the TDM interface, checking the corresponding channel number and reading data from the corresponding area of the memory; In the case of the memory access, determining a memory output pointer value of the RTP packet processor in the TDM interface, and accessing the data indicated by the value to the system highway.

Preferably, the buffer overflow and the buffer overrun are updated by comparing a rate at which a packet is input from the LAN interface to the internal memory of the RTP packet processor and a rate at which a packet is taken at the TDM interface.

Hereinafter, with reference to the accompanying drawings as follows.

2 is an apparatus for processing and converting an RTP packet into a TDM according to an embodiment of the present invention.

2, a LAN interface 220 for interfacing with the LAN 210 to receive a packet having information and an RTP packet included in voice, and analyzing and storing data input through the LAN interface 220. RTP packet processing unit 230 to be transmitted to the TDM interface 250 or the central processing unit 240 according to whether the RTP packet, and the central to transfer the information so that the RTP packet and TDM packet can be converted to the RTP packet processing unit 230 A processor 240 is included, and reference numeral 241 denotes a ROM and 242 denotes an SRAM.

The apparatus and method for controlling an RTP packet interface as described above will be described below with reference to FIGS. 2 to 4.

First, referring to FIG. 2, data input through the LAN interface 220 connected to the LAN 210 is input to the RTP packet processor 230. At this time, the data input to the RTP packet processing unit 230 is a packet with information and the RTP packet including the actual voice data is input. Here, a packet with information is needed by the central processing unit 240, and the RTP packet is sent to the TDM interface 250.

To this end, the RTP packet processing unit 230 analyzes data input through the LAN 210 and converts the data into a TDM format internally when the corresponding data is an RTP packet to connect to the TDM interface 240 to the system highway. If the corresponding data is a packet (Control, etc.) to go to the central processing unit 240, it is sent to the central processing unit 240.

In this case, when a new connection is initially established in the system, the central processing unit 240 receives information about a corresponding connection through a signal line (Signal) from the system and refers to the memory 231 of the RTP packet processing unit 230 by referring to the information. ) Will record the processing information.

The RTP packet processor 230 analyzes the data coming from the external LAN interface 220 using the connection information to determine whether it is an RTP packet or not, and, in the case of an RTP packet, an internal memory (SRAM) for internal processing. 231 stores data and updates various parameters.

In addition, the RTP packet processor 230 converts the TDM packet transmitted from the TDM interface 250 into an RTP packet, and transmits the TDM packet to the LAN 210 through the LAN interface 220.

The internal memory 231 of the RTP packet processor 230 is as shown in FIG. 3, and FIG. 4 is a diagram illustrating a method of processing an RTP packet.

3 and 4, when the central processing unit 240 initially establishes a new connection in the system, the central processing unit 240 receives information about the corresponding connection from the system through a signal line (Signal), and refers to the RTP packet by referring to the information. The parameters described later are written in the memory 231 of the processor 230 (S201). Here, all the parts which are not used because of no connection are all set to '0'. However, in the case of FP (IDLE Fill Pattern), a null value (the value used for each system is written) is written.

Among the parameters for initial connection information, the valid bit is set to '1', the first bit is set to '0', and the LC (Law Conversion) value is A-law, u. If -law is required, it is set to '1', FP is null data to be used when there is no data, INP (Input Pointer), OUTP (Output Pointer) is '0', and JBT (Jitter Buffering Time) area is Size of buffer for RTP packet to use, PSTS (Packet Last Time Stamp) value is set to '0'. In the Port section, write down the port number that RTP should use. The rest of the data is ignored.

Also, the packet counter (PKCNT), sequence number (SN), sequence number error (SNE), buffer underrun (BUV), and buffer overflow (BOV) are written as' 0.

In addition, when the RTP packet enters through the LAN interface 220, the RTP packet processor 230 determines which part of the memory 231 to use by checking a corresponding port value. Once determined, the valid bit (V bit) of the memory 231 is examined (S203).

At this time, when the valid bit is checked (S205) and the valid bit is not '1', the valid bit is sent to the central processing unit 240 without being stored in the memory 231 even in the case of the RTP packet (S219). .

If the valid bit is '1', the actual data is stored in the portion indicated by the value portion of the input pointer (INP) (S207). After the data is saved, the value of the input pointer INP is increased by the amount of stored data and written in the input pointer INP. Thereafter, the current timer value is written in the Packet Last Time Stamp (PSTS) field in which the current packet is stored (S209).

In addition, the TDM interface 250 receives a clock and a frame header (FH: notifying the start of the system bus) from the system and loads corresponding data on the system highway. This TDM interface 250 consists of synchronization, clock, transmit and receive lines.

At this time, when the order of the corresponding channels, the TDM interface 250 requests data together with the number of the channel corresponding to the RTP packet processor 230 (S211). After checking the channel number, the RTP packet processing unit 230 reads the corresponding memory 231 region (S213).

When the valid bit is not '1' when the memory 231 is accessed, the null data in the FP (IDLE Fill Pattern) is transmitted. When the valid bit is '1', the first bit is checked. If it is not '1', it should be determined that the output pointer (OUTP: OUT Pointer) value is the start of the corresponding data access.

The value of the output pointer OUTP is subtracted by the value of the JBT (Jitter Buffering Time) from the value of the input pointer (INP), and the internal timer in the amount of data (time, e.g. 20ms) delivered by one packet of the current RTP Note the limit as much as the difference between and PSTS. Here, the internal timer is a timer driven by using the frame header (FH) of the TDM interface 250. When the frame header is operated once, it means that data is loaded once on all TDM channels. Each time you run it, the timer also increases by 1. After that, the data of the place designated by the output pointer OUTP is taken.

When the first bit is set to '1', the data in the output pointer OUTP is taken, and the output pointer value is increased by one and written in the corresponding area of the memory 231 (S215).

At this time, each time a packet is stored once, the packet counter PKCNT is incremented by 1, and the sequence number SN is written as the current value. ).

Also, a buffer overflow (BOV) and a buffer underrun (BUV) are displayed by comparing a speed at which a packet comes in and a speed at which data is taken from the TDM interface 250.

In this case, the buffer overflow (BOV) and the buffer underrun (BUV) are calculated by recalculating the output pointer when the packet is stored, and comparing the existing output pointer or by recalculating the output pointer when sending data to the TDM interface. Compare it with the existing output pointer and write it down (S217).

If the result of the comparison between the buffer overflow (BOV) and the buffer underrun (BUV) is '0', there is no change, and the recorded value records the difference between the two existing output pointers and the newly calculated output pointer. If the existing output pointer is larger (that is, the difference between input pointers is small), write the value in the buffer overflow (BOV) and the buffer underrun (BUV) write '0', otherwise the buffer underrun (BUV) ) And '0' for the buffer overflow (BOV).

In addition, if the buffer underrun occurs continuously, when the output pointer OUTP and the input pointer INP are the same, the data is sent out as FP (IDLE Fill Pattern). At this time, the central processing unit periodically checks the buffer overflow (BOV), the buffer underrun (BUV), and the sequence error (SNE), and takes action when an error occurs. When the output pointer OUTP is recalculated for the buffer overflow BOV and the buffer underrun BUV, the value is not written down.

As described above, the RTP packet processing unit 230 analyzes the data coming from the LAN interface 220 and stores the data in the case of the RTP packet, converts the data into the TDM format, and sends the data to the TDM interface. If the packet is to be sent to the central processing unit.

As described above, according to the apparatus and method for processing an RTP packet in an Internet telephone exchange according to the present invention, an RTP packet processing unit is provided between a LAN interface and a central processing unit, so that a packet received from the LAN interface is processed as an RTP packet. Therefore, by sending the data to the TDM interface in the TDM format, the amount of data that enters the central processing unit can be reduced, thereby reducing the load of the central processing unit and operating without having a separate digital signal processor.

Claims (4)

In the internet telephone exchange, A LAN interface for receiving a packet having information and an RTP packet containing voice information; A TDM interface for requesting channel numbers in channel order and sending them to the system highway; An RTP packet processing unit for analyzing and storing data input through the LAN interface and converting the RTP packet into a TDM format if the RTP packet is transmitted to the TDM interface; And a central processing unit for recording connection information in the RTP packet processing unit so that the RTP packet processing unit and the TDM packet can be mutually converted by the RTP packet processing unit. The method of claim 1, The RTP packet processing unit includes a memory therein, analyzes data coming from a LAN interface, converts the RTP packet into a TDM format using an internal memory, and transfers the data to the TDM interface. Apparatus for processing RTP packets in an Internet telephone exchange, characterized in that the transfer. In the internet telephone exchange, Recording, by the central processor, connection information received through the system highway to a memory of the RTP packet processor; Checking, by the RTP packet processor, a receiving port of the RTP packet from the LAN interface, determining a recording area of the internal memory, and checking valid bits; Storing data in a memory area indicated by an input pointer value when the valid bit is 1, updating an input pointer and a packet storage time, and transferring the data to a central processing unit when the valid bit is not 1; Thereafter, upon receiving the data request together with the corresponding channel number from the TDM interface, checking the corresponding channel number and reading data from the corresponding area of the memory; In the case of the memory access, the RTP packet processing method in the TDM interface comprising the step of determining the value of the memory output pointer of the RTP packet processing unit, and sending the data indicated by the value to the system highway; . The method of claim 3, wherein RTP packet in the Internet telephone switch, characterized in that the buffer overflow and the buffer overrun is updated by comparing the rate at which the packet enters from the LAN interface to the internal memory of the RTP packet processor and the rate at which the packet is taken by the TDM interface. Treatment method.