CN1185830C - Long-range central management method of digital video systems - Google Patents

Abstract

The invention discloses a remote centralized management method of a digital video system, which is used for the remote centralized management of the digital video system. The technical solution at least includes: transforming the interface of the adapter in the digital video system, applying the protocol stack of IP data forwarding, realizing simple IP data forwarding between the Ethernet interface of the adapter and the service data interface, so as to complete the digital video system The local and remote network management are interconnected with LAN IP to realize the common channel transmission of network management data and business data, and realize the remote centralized management of low-cost digital video system equipment.

Description

Remote Centralized Management Method of Digital Video System

technical field

The invention relates to the realization technology of remote centralized management in the network, in particular to the remote centralized management technology and realization method of digital video equipment on the network.

Background technique

A typical digital video system generally consists of the following five main functional modules:

Encoder: perform A/D conversion, quantization and compression coding on the input analog TV signal (image and sound), and output the transport stream (TransportStream, hereinafter referred to as transport stream) of ITU-T H222.0 (ISO/IEC13818-1) standard or TS).

Decoder: The completed function is opposite to that of the encoder: input standard transport stream, after decoding, D/A conversion, and encoding of analog signal, output full TV signal conforming to ITU-R 601 standard. The transport stream input by the decoder can contain a single program or multiple programs.

Multiplexer: Complete the system layer (System Layer) multiplexing function of the transport stream, multiplex the multiple transport streams, and output the transport stream conforming to ITU-T H222.0 (ISO/IEC13818-1).

Adapter: Complete the two-way adaptation of the transport stream data format to the SDH frame structure, the two-way conversion from the transport stream interface to the ITU-T G703 telecommunication interface, and realize the transmission and reception of transport stream data on the SDH network.

Distributor: Complete the hard copy of the transmission data stream from one to multiple, that is, the simple function of one point and many. Allocators are not manageable.

A typical system network is shown in Figure 1. This is to realize the transmission of digital radio and television programs on the SDH (Synchronous Digital Hierachy is the most common optical communication system on the telecommunications network, and can also refer to optical communication equipment that meets the requirements of this system) network. In this transmission mode, the solid line is the digital video service data link, and the dotted line is the network management data link. A/V stands for analog audio and video signals, ENC stands for encoder, DEC stands for decoder, MUX stands for multiplexer, NA stands for adapter, and DIS stands for distributor.

One or more channels of analog full TV signal A/V are encoded by the corresponding encoder ENC into a transport stream TS, and after being multiplexed by the multiplexer MUX, they are sent to the adapter NA to be converted into ITU-T G703 data streams and sent to the SDH network.

The ITU-T G703 data flow received by the receiving end from the SDH network is converted into a transport stream TS by the adapter NA, and then distributed to one or more decoders DEC by the distributor DIS to decode one or more analog full TV signals. Thus, the long-distance transmission of digital video service data is completed.

In this transmission system, encoders, decoders, multiplexers and adapters generally provide Ethernet (Ethernet) interfaces for device management, and as shown in Figure 1, a local area network for management can be formed locally ( LAN).

Since the encoding, sending, receiving and decoding ends of digital radio and television programs are often tens, hundreds to thousands of kilometers apart geographically, to realize remote centralized network management between two or more digital radio and television systems, it is necessary to Between these digital broadcasting and television systems, that is, between these local area networks, a network management data communication network supporting the IP protocol is established.

The solution shown in Figure 2 is usually adopted, which is to equip several network interconnection devices on these LANs, such as gateways or routers 101 and 201, to interconnect each local area network (LAN) with the wide area network (WAN) to form a remote centralized network management system , the management system 102 (NMS) on the microcomputer and the management agent (Agent) on each device exchange management data with each other to realize remote centralized management of the devices in the entire network. The business data between the digital video equipment 104,204 is interconnected through the adapter 103,203.

The main defect of this method is that an additional data communication network needs to be established on the SDH transmission network to support the exchange of management data, which requires another channel to be occupied on the dedicated high-speed SDH network. The transmission rate of management data is low, generally only a few Kbit/s to tens of Kbit/s, and occupying an SDH channel > 2Mbit/s is obviously a waste of resources; the added network management network system also needs to increase the gateway or router for network interconnection , increase the interface SDH service board between these interconnected devices and the SDH transmission network, which obviously increases the hardware cost of the networking.

Contents of the invention

The purpose of the invention is to realize the remote centralized management of the digital video system on the network at low cost.

The basic idea of the present invention is: simulate a WAN interface for network management IP on the original remote interface of the adapter, increase the network management IP data forwarding function between the newly added WAN interface and the original Ethernet interface, and transfer the network management IP The data is converted into the same transport stream packet TSP as the service data, and is transmitted in the same channel as the service data.

Preferably, a specific network byte sequence encapsulation adaptation layer capable of mutual conversion to both ends is set between the IP data and the transport stream TS, and the bidirectional conversion between the IP data and the transport stream TS is completed through this adaptation layer.

Preferably, the protocol stack for converting IP data is specifically selected to be expressed in IP/like AAL5/TS.

Preferably, AAL5-like encapsulation is first performed on the IP data, and TS integer fragmentation is performed on the encapsulated AAL5-like datagram.

Preferably, when performing AAL5-like encapsulation, the number of bytes of the encapsulated datagram is an integer multiple of 184 bytes of the transport stream packet TSP payload.

Preferably, when performing TS fragmentation, an identifier different from other service data should be set in the header format of the transport stream packet TSP.

Preferably, the TSP header format contains at least the following information: A, the specific PID identifier of the network management IP data; B, the priority identifier of the network management IP data; C, the initial identifier of the network management IP data.

Preferably, a network management PID filter is set at the service data receiving end to identify the PID as the transmission stream packet TSP of the network management PID, and continuously receive and count it, if the number of the transmission stream packet TSP of the received network management IP is not greater than the specified value , it is regarded as received correctly; otherwise, discard all transport stream packets TSP received this time, and start counting again.

Preferably, when the reception is correct, the data in the TSP payload of the transport stream packet is first assembled, handed over to the AAL5 class for adaptation and processing into IP data, and handed over to the IP protocol for processing after verification is correct.

Through the above method, the common channel transmission of network management data and video service data can be completed. Obviously, this method reduces network hardware equipment, realizes low-cost remote centralized management, and improves network bandwidth utilization.

Description of drawings

Fig. 1 shows the business network of digital video system;

Figure 2 shows IP interconnection using routers to realize remote centralized management;

Figure 3 shows IP interconnection using adapters for remote centralized management;

Fig. 4 shows the complete protocol stack for the adapter to complete IP data forwarding;

FIG. 5 shows a schematic diagram of a transport stream packet TSP format;

Fig. 6 shows the class AAL5 encapsulation format according to a preferred embodiment of the present invention;

Fig. 7 shows the star network mode of practical remote centralized management;

Fig. 8 shows a ring networking mode that is practical for remote centralized management.

Detailed ways

In order to make the object, technical solution, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and examples.

Fig. 3 is the schematic diagram of the embodiment of the present invention, and the service data between digital video equipment 104,204 is interconnected by adapter 103,203, and two local area networks (LAN) are directly connected on the wide area network (WAN) by adapter 103,203, adapter 103 The Ethernet IP address of the adapter 203 is 10.14.3.54, and the WAN IP address is 11.1.1.1; the Ethernet IP address of the adapter 203 is 12.1.1.1, and the WAN IP address is 11.1.1.2.

The adapter in the digital video system has two interfaces of Ethernet and remote network like the router. The two interfaces of the adapter are transformed, and a WAN interface for network management is simulated on the original remote network DC-3 interface. The network management IP data forwarding function (that is, the function completed by the routers 101 and 102 in FIG. 2 ) is added between them, and the network management data is sent and received together with the service data.

The specific method is as follows: the pSOS real-time operating system is used on the adapter, which itself realizes a relatively complete TCP/IP protocol. Implement an interface that works in a specific way for the TCP/IP module of the pSOS system, and the interface for this specific working mode is realized on the DS-3 interface. In addition, the local Ethernet interface for equipment network management is used; between these two interfaces, the TCP/IP module of pSOS is used to complete the forwarding of IP data, and realize the interconnection of LANs in different locations. This method can be referred to as IP OverTS for short. Its schematic diagram is shown in Figure 3.

The complete protocol stack for the adapter to complete IP data forwarding is shown in Figure 4. The underlined part of the protocol stack is the protocol implemented by the IP Over TS of the present invention for processing IP data encapsulation, sending and receiving.

The specific implementation method of encapsulating data according to the protocol shown in Figure 4 is: the adapter first performs AAL5 (ATM Adaptation Layer 5)-like encapsulation on the IP data that needs to be forwarded, and then fragments it in the Transport Stream Packet (TSP) In, send and receive together with business data.

According to the H.222.0 standard, the uniform encapsulation format for long-distance transmission after TV programs are coded and compressed is TSP. The general length of the TSP is 188 bytes, including a 4-byte header (that is, fields 1-6 in FIG. 5 ), and the length for carrying valid data is 188-4=184. See Figure 5 for the TSP format. As shown in Figure 5, the meaning and length of each field in the TSP format are:

1. sync_byte, synchronization byte, 8bit. It is 0×47, which realizes the boundary of each TSP in the transport stream and the synchronization of data sending and receiving.

2. transport_error_indicator, transmission error indicator, 1bit. This flag will be set to 1 if an error occurred during the transmission of this TSP, otherwise it will be 0.

3. payload_unit_start_indicator, payload unit start flag, 1bit. This flag will be set to 1 if the TSP carries the first fragment of a payload unit, otherwise it will be 0.

4. transport_priority, transmission priority. If the data carried by this TSP is considered more important than other data, this flag will be set to 1, otherwise it will be 0.

5. PID, group identifier, 13bit. TSPs with the same PID represent the same type of data generated by the same data source (such as compressed video source, compressed audio source, etc.).

6. transport_scrambling_control, transmission scrambling control, 2bit,

adaptation_field_control, adaptation field control, 2bit,

continuity_counter, continuity count, 4bit.

7. Payload or adaptation field.

TSP has a similar order to ATM cells (cells) during transmission, and AAL5 is also a common and effective encapsulation form for IP datagrams, so the adapter will first perform a type of AAL5 on the IP datagrams that need to be sent. Network Byte order (Network Byte order) encapsulation, the encapsulation format is shown in Figure 6. As shown in Figure 6, the field meaning and length of the AAL5-like encapsulation format as a preferred implementation mode are respectively:

Payload: generally an IP datagram. Its length is self-contained.

Padding: 0-183 bytes, the entire encapsulated data packet length is padded to an integer multiple of 184 of the TSP payload length.

Length: 2 bytes, which is the length of the payload plus padding bytes, excluding the length and CRC fields.

CRC: 4 bytes, for the CRC check of all the previous fields, the polynomial selection is

X ³² +X ²⁶ +X ²³ +X ²² +X ¹⁶ +X ¹² +X ¹¹ +X ¹⁰ +X ⁸ +X ⁷ +X ^{5 +X 4 +} X ² +X+1

Usually the maximum efficiency transmission unit (MTU) of Ethernet is 1500 bytes. Considering the efficiency of transmission, the maximum byte length after encapsulation should take such a value: close to 1500 bytes and an integral multiple of the TSP payload length of 184 bytes. In this way, the IP datagram transmitted from the LAN can be placed in an AAL5-like datagram, and can be sent with an integer number of TSPs after fragmentation.

Specifically, if 184×9=1656 is selected, and the 6-byte fixed-length tail of the AAL5-like encapsulation is subtracted, then the maximum transmission unit MTU=1656-6=1650 bytes in length. The DS-3 interface informs the IP protocol module of the MTU, then the length of the IP datagram delivered by the IP protocol to the DS-3 interface is not greater than the MTU.

For the data encapsulated according to the above method, the sending end fragments it according to the length of 184 bytes, puts it in the payload part of the TSP, and sends it together with the business data.

The TSP header format for the fragmentation of the IP data data part is specially defined as follows:

sync_byte, transport_error_indicator: filled according to the format of H.222.0.

payload_unit_start_indicator: If it is the last piece of AAL5-like encapsulation, set it to 0, otherwise it is 1.

transport_priority: Assuming that the network management data is more important, set it to 1.

PID: It is a selected legal value different from other service data PIDs, called network management PID. The network management PIDs of the sending and receiving parties must be the same to achieve duplex communication. Users can configure the network management PID, but it cannot conflict with the PID of other service data.

transport_scrambling_control, adaptation_field_control: 00, 01 respectively.

Continuity_counter: According to the H.222.0 protocol, sequential accumulation.

The receiving end is provided with a filter of the network management PID, and continuously receives and counts the transmission stream packet TSP containing the network management PID. When a packet with a payload_unit_start_indicator of 0 is encountered, and the number of previously received packets with a payload_unit_start_indicator of 1 is not greater than 8, the data in the received TSP payload is assembled and handed over to AAL5 for adaptation and processing into IP data, and the verification is correct After that, it is handed over to the IP protocol for processing.

When more than 8 packets with payload_unit_start_indicator of 1 are received, it indicates that the reception is wrong, all TSP packets received this time are discarded, and counting is restarted.

Now the adapter has two network interfaces. According to the definition of IP protocol, it knows the direct routes of these two networks; while the digital video system is generally relatively simple in networking, and the IP interconnection of the whole network network management can be realized by using the default route configuration.

The detailed routing table for adapter 103 may be: 0. 0. 0. 0 0. 0. 0. 0 11. 1. 1. 2 10. 14. 0. 0 255. 255. 252. 0 10. 14. 3. 254 11. 1. 0. 0 255. 255. 0. 0 11. 1. 1. 1

The detailed routing table for adapter 203 may be: 0. 0. 0. 0 0. 0. 0. 0 11. 1. 1. 1 11. 1. 0. 0 255. 255. 0. 0 11. 1. 1. 2 12. 1. 0. 0 255. 255. 0. 0 12. 1. 1. 1

Figure 7 shows a star network. Figure 8 shows a ring network. In these two figures, DVN is a digital video network, 102 is a network management system NMS, "cloud" indicates a local network management LAN composed of digital video equipment, PC indicates a network management computer, and a dotted line indicates a DS-3 link.

All local network management LANs are interconnected through adapters.

In Fig. 7, the three sub-nodes are respectively connected to the adapters 103, 503, 603 of the central node through adapters 203, 303, 403. Each adapter has two interfaces, corresponding to two IP addresses.

Adapter 103: 10.14.3.254/11.1.1.1;

Adapter 203: 12.1.1.1/11.1.1.2;

Adapter 303: 13.1.1.1/11.1.1.3;

Adapter 403: 14.1.1.1/11.1.1.4;

Adapter 503: 10.14.1.2/11.1.1.5;

Adapter 603: 10.14.1.3/11.1.1.6; 103 routing table 203 routing table 10. 14. 3. 2540. 0. 0. 0 0. 0. 0. 0 11. 1. 1. 310. 14. 0. 0 255. 255. 252. 0 10. 14. 3. 25411. 1. 0. 0 255. 255. 0. 0 11. 1. 1. 1 12. 1. 1. 10. 0. 0. 0 0. 0 0. 0 11. 1. 1.5 11. 1. 0. 0 255. 255. 0. 0 11. 1. 1.212. 1. 0. 0 255. 255. 0. 0 12. 11. 1 303 routing table 403 routing table 13. 1. 1. 10. 0. 0. 0 0. 0. 0. 0 11. 1. 1. 111. 1. 0. 0 255. 255. 0. 0 11. 1. 1. 313. 1. 0. 0 255. 255. 0. 0 13. 1. 1. 1 14. 1. 1. 10. 0. 0. 0 0. 0. 0. 0 11. 1. 1. 611. 1. 0. 0 255. 255. 0. 0 11. 1. 1. 414. 1. 0. 0 255. 255. 0. 0 14. 1. 1. 1

Figure 8 shows a ring networking scheme, in which the central node and three ring nodes are connected in sequence, and the IP addresses of their adapters 103, 203, 303, and 403 are:

Adapter 103: 10.14.1.5/15.1.1.1;

Adapter 203: 16.1.1.1/15.1.1.2;

Adapter 303: 18.1.1.1/15.1.1.3;

Adapter 403: 17.1.1.1/15.1.1.4;

The detailed routing table is as follows: 103 routing table 203 routing table 10. 14. 1. 50. 0. 0. 0 0. 0. 0. 0 15. 1. 1. 210. 14. 0. 0 255. 255. 252. 0 10. 14. 1. 515. 1. 0. 0 255. 255. 0. 0 15. 1. 1. 1 16. 1. 1. 10. 0. 0. 0 0. 0. 0. 0 15. 1. 1. 315. 1. 0. 0 255. 255. 0. 0 15. 1. 1. 216. 1. 0. 0 255. 255. 0. 0 16. 1. 1. 1 303 routing table 403 routing table 18. 1. 1. 10. 0. 0. 0 0. 0. 0. 0 15. 1. 1. 315. 1. 0. 0 255. 255. 0. 0 15. 1. 1. 418. 1. 0. 0 255. 255 0. 0 18. 1. 1. 1 17. 1. 1. 10. 0. 0. 0 0. 0. 0. 0 15. 1. 1. 115. 1. 0. 0 255. 255. 0. 0 15. 1. 1. 417. 1. 0. 0 255. 255. 0. 0 17. 1. 1. 1

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the scope of the present invention. within the scope of the claims.

Claims (8)

1, a kind of remote centralized management method of digital video system, it is characterized in that: simulate the wide area network interface that a network management IP is used on original adapter remote interface, between this newly added wide area network interface and original Ethernet interface Add the network management IP data forwarding function in between, convert the network management IP data into the same transmission flow packet TSP as the business data, and transmit it in the same channel as the business data; and, A specific network byte sequence encapsulation adaptation layer is set between the IP data and the transport stream TS, which can be converted to both ends, and the bidirectional conversion between the IP data and the transport stream TS is completed through this adaptation layer. 2. The remote centralized management method of the digital video system according to claim 1, characterized in that: the protocol stack for IP data conversion is specifically selected as the protocol stack expressed by IP/class AAL5/TS. 3. The remote centralized management method of a digital video system according to claim 2, characterized in that: the IP data is first encapsulated in an AAL5-like manner, and the encapsulated AAL5-like datagram is then fragmented into TS integers. 4. The remote centralized management method of digital video system according to claim 3, characterized in that: when carrying out class AAL5 encapsulation, the number of bytes of the encapsulated datagram is an integer multiple of 184 bytes of transport stream packet TSP payload. 5. The remote centralized management method of a digital video system according to claim 3, characterized in that: when performing TS fragmentation, an identifier different from other service data should be set in the header format of the transport stream packet TSP. 6. The remote centralized management method of the digital video system according to claim 5, characterized in that: the TSP header format at least contains the following information: A. The specific PID identification of network management IP data; B. Network management IP data priority identification; C. Network management IP data start identifier. 7, according to the remote centralized management method of the digital video system of claim 6, it is characterized in that: the network management PID filter is set at the service data receiving end, the transmission stream grouping TSP that the identification PID is the network management PID is continuously received and counted, If the number of received transport stream packet TSPs of the network management IP is not greater than the specified value, it is considered to be received correctly; otherwise, all transport stream packet TSPs received this time are discarded and counting is restarted. 8, according to the remote centralized management method of the digital video system of claim 6, it is characterized in that: when receiving correctly, the data in the transport stream packet TSP load is assembled earlier, and handed over to class AAL5 adaptation processing into IP data, After the verification is correct, it is handed over to the IP protocol for processing.

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