CN1368814A - Method for configuring network by overlapping ATM with Internet protocols - Google Patents

Abstract

The present invention relates to a method for constructing a superimposed network of Asynchronous Transfer Mode (ATM) and Internet Protocol (IP), which implements ATM switching and high-speed IP routing switching at the same time with a unified switching network in the same broadband multi-service switch , and can realize ATM and IP business intercommunication. The unified switching network adopts the "one machine, two planes" scheme, including setting: an ATM service plane, a high-speed IP service plane, a unified core switching platform, an intercommunication function module for information exchange between ATM and IP services, respectively Two control modules that control the ATM and high-speed IP service planes, and a multi-protocol sign switching (MPLS) control module that uniformly controls ATM/IP services.

Description

A method for superimposing asynchronous transfer mode and Internet protocol to build a network

The present invention relates to the field of switching technology, more precisely, it relates to a method for superimposing asynchronous transfer mode (ATM) and Internet protocol (IP) to build a network, and is a method for solving the problem of asynchronous transfer mode (ATM) and Internet protocol When (IP) overlapping network is built, it is a kind of technical scheme of one machine and two planes applied in the broadband multi-service switchboard.

With the rapid and vigorous development of data services, the demand for network bandwidth is increasing day by day, and network broadband is becoming the trend of network development. There are mainly two types of solutions to solve network broadband, namely Asynchronous Transfer Mode (ATM) technology and Internet Protocol (IP) technology.

Internet Protocol (IP) technology, hereinafter referred to as IP network technology, is advocated by traditional data communication manufacturers. Its advantage is that the routing system is flexible, and it is suitable for non-real-time information due to the non-connection-oriented best-effort service method. However, traditional IP network technology cannot guarantee the quality of service (QoS) requirements for delay, bandwidth, etc., and cannot meet the transmission requirements of real-time information such as voice and video.

Asynchronous Transfer Mode (ATM) technology, advocated by traditional telecom manufacturers, adopts connection-oriented transmission technology, can support voice, data and image communication, and combines the advantages of packet switching and circuit switching, so it has good service quality ( QoS) guarantee, its disadvantages are: the signaling for establishing a connection is too complicated, the routing flexibility is not high, and the efficiency is not high when transmitting short general data.

With the vigorous development of data services, the traffic of the network continues to increase. To analyze the existing traffic of the network, especially the traffic of the network in the metropolitan area network, on the one hand, there are a large number of traffic such as 3W, FTP, E-mail, etc. Services that do not require strict quality of service (QoS) guarantees are realized through traditional IP technologies; Quality of Service (QoS) Guaranteed services are realized by carrying IP through ATM.

ATM and IP respectively provide the most effective solutions for network services with different quality of service (QoS) requirements, while a broadband network must be able to meet the needs of two types of services at the same time: enterprise interconnection and real-time video with high quality of service requirements Business and Internet access business with lower requirements on service quality. In order to support two kinds of services with different quality (QoS) requirements at the same time, there are three traditional solutions: including pure ATM solution, pure IP solution and ATM+IP stacking solution.

Referring to Fig. 1, it shows the realization principle of the ATM switch service, which is a pure ATM solution. For example, many cities in China choose to use ATM backbone switches and edge switches to build ATM multi-service networks, and adopt various IPOA (IP Over ATM) technologies, such as using IPOA, 1483B, LANE, MPOA and other protocols to carry IP services.

The ATM switch includes an input line interface unit 11 , an internal switching unit 12 , an output line interface unit 13 and an ATM control unit 14 .

Wherein the input line interface unit 11 comprises physical layer (PHY) 111, ATM layer processing 112 and ATM queue management 113, and physical layer (PHY) 111 extracts ATM cell from the physical link (IP packet is carried on the access part In the ATM cell); ATM layer processing 112 extracts the VPI/VCI value in the cell header from the ATM cell, and correspondingly generates the internal cell format (such as adding the internal cell encapsulation header Tag, etc.) after querying the connection routing table And carry out ATM traffic monitoring; ATM queue management 113 carries out each virtual channel (per VC) queuing and dispatching by service class under the control of ATM control unit 14.

Output line interface unit 13 comprises ATM queue management 131, ATM layer processing 132 and physical layer (PHY) 133, and ATM queue management 131 carries out output queuing under the control of ATM control unit 14; ATM layer processing 132 removes internal cell encapsulation head ( Tag) and cell header switching; the physical layer (PHY) 133 sends the cell to the physical link.

The format of the ATM cell input by the ATM switch is cell header (including VPI/VCI) + cell payload (48-byte fixed-length data); the format of the fixed-length packet exchanged inside the ATM switch is internal routing label Tag + cell header + Cell payload; the format of the ATM cell output by the ATM switch is cell header + cell payload.

This pure ATM technology encapsulates IP data into ATM cells, and can provide IP with connection-oriented, bandwidth-controllable, high-quality multimedia applications and business user interconnection services with high security and low delay. Its advantage is that it has strict service quality assurance, can carry out multi-service bearing and mature technology; its disadvantage is that for a large number of Internet (Internet) Internet access business applications such as WWW browsing, FTP, and E-mail, there are complex protocols (two sets of protocols) ), there is a cell tax when carrying IP, the transmission efficiency is low, and distributed routing and forwarding cannot be realized. This simple "ATM+IP" method cannot meet the needs of providing a large number of simple and cheap Internet services for broadband networks.

It should be pointed out that although some ATM switches can provide interfaces such as POS (Package Over SDH) and GE (Gigabit Ethernet), because the POS/GE interface on the ATM switch uses IPOA (IP OVERATM) to connect to On the ATM switching core, there are also disadvantages of complex protocols and high overhead, and distributed routing and forwarding cannot be realized. Therefore, even if all IP service interface boards such as POS are plugged into the ATM switch, it is still essentially different from the real Gigabit Switch Router GSR (Gigabyte Switch Router).

Referring to Fig. 2, it shows the realization principle of the high-speed router service, which is a solution for constructing a metropolitan area network by using a high-speed switching router. Adopt the gigabit switching router (GSR) with IP technology as the core, and network through POS (Package Over SDH) or Gigabit Ethernet (GE), eliminating the need for the middle ATM layer to directly carry IP.

A gigabit switch router (GSR) with IP technology as its core includes an input unit 21 , an internal switching unit 22 , an output unit 23 and an IP control unit 24 .

Wherein input unit 21 comprises physical layer (PHY) 211, IP layer processes 212 and IP queue management 213, physical layer (PHY) 211 extracts IP packet from physical link by POS/GE interface; IP layer processes 212 to IP packet RED, WFQ, CBQ (representing traffic monitoring strategy respectively) etc. process and cut (divide) piece into fixed-length data packet with IP, carry out Internet control; IP queue management 213 extracts in the IP header under the control of IP control unit 24 Destination IP address, check routing table, classify IP flow and monitor IP flow.

Output unit 23 includes IP queue management 231, IP layer processing 232 and physical layer (PHY) 233, and IP queue management 231 carries out reorganization IP packet and output queuing to IP slice under the control of IP control unit 24; IP layer processing 232 finishes L3/L2 (layer processing encapsulation of IP network and Ethernet) address mapping; the physical layer (PHY) 233 sends the IP packet to the physical link through the POS/GE interface.

The format of the input IP packet of the high-speed router is IP header + variable-length IP payload data; the format of the fixed-length packet exchanged internally by the high-speed router is internal routing label Tag+IP fragment fixed-length data; the format of the output IP packet of the high-speed router is IP header + Variable length IP payload data.

The advantages of this way of carrying IP are obvious: high IP transmission efficiency, simple protocol, easy expansion of port rate, simple network, low operating cost, can be based on a large and stable SDH network, and has certain service quality assurance capabilities. Its disadvantages are: poor flow control and bandwidth management capabilities, poor manageability and security, it is difficult to support business users' enterprise interconnection and real-time multimedia services, and it is difficult to guarantee the service quality of voice communication and video communication, so it is more suitable for best-effort transmission Internet backbone network. At present, many operators have realized the service limitations of using a simple high-speed router (GSR) to build a network.

It should also be pointed out that although some GSR equipment can provide ATM interfaces, the ATM interfaces on the GSR equipment are terminal-side equipment on the ATM network. Before entering the GSR switching network, all virtual channels (VCs) have been terminated. The cells are reassembled into IP packets for forwarding, so the GSR cannot realize the exchange of ATM VCs, and it cannot have the perfect traffic engineering unique to ATM switches. In layman's terms: the ATM interface provided by GSR cannot provide real ATM applications.

As shown in Figure 1 and Figure 2, it is difficult to simply rely on one technology to meet the business requirements of different users and different service qualities. Both ATM and IP have their own advantages. Using ATM to carry IP can obtain high-quality services with controllable bandwidth, but it has the disadvantages of high overhead, complex protocols, and low efficiency; using GSR or Gigabit Ethernet to carry IP, It has the advantages of high transmission efficiency and simple networking, but it loses the strict IP QOS guarantee, the bandwidth is uncontrollable, and it cannot meet the high service quality requirements of business users. It can be seen that the unity of this contradiction must rely on the mutual compensation of these two technologies to achieve.

Referring to Fig. 3, the figure shows the scheme of superimposed network construction using IP+ATM, that is, using ATM switches and high-speed switching routers to superimpose network construction. By adopting the way of constructing an ATM multi-service network and superimposing a pure IP network at the same time, the broadband network can be realized by meeting the demands of high-quality enterprise interconnection services and low-quality Internet access services at the same time.

In view of the two main types of services in the network, one is enterprise interconnection services and real-time video services with higher service quality requirements, and the other is Internet access services with lower service quality requirements, and two types of services are generated to meet these two types The business needs of the network, that is, building an asynchronous transfer mode (ATM) multi-service network and superimposing a pure international Internet (IP) network to meet the requirements of high-quality enterprise interconnection, real-time video services and low-quality Internet business needs.

As shown in the figure, when users 311 and 312 in the user network are performing enterprise interconnection services and real-time video services with high service quality requirements, they connect to the ATM switch 331 at the backbone layer through access layer devices 321 and 322 to enter the ATM local network 33; the users 313 and 314 in the user network enter the IP local network 34 through the high-speed router 341 connected to the backbone layer through the access layer routing equipment 323 and 324 when performing Internet access services with lower quality of service requirements, and the ATM local network 33 The information interaction between the ATM switch 331 and the high-speed router 341 in the IP local network 34 has an intercommunication bottleneck so far.

The most obvious advantage of adopting ATM+IP overlapping network construction method is that it can fully meet the business needs of different users and provide the most effective solution for businesses with different service quality requirements. Use ATM switching technology to provide services that require service quality assurance, and use high-speed router technology to provide traditional IP services. Through the combination of ATM and IP, high-efficiency services are provided for businesses with different service quality requirements, and the advantages of ATM switching and IP routing are fully utilized.

However, the disadvantages of adopting ATM+IP overlapping network construction method are also very obvious: two sets of independent network management systems need to be provided for overlapping network construction, which complicates the network management process; the investment of building two sets of network systems is large, which increases the investment of operators Construction costs and risks; the intercommunication between the two networks means that there is still a bandwidth bottleneck at the connection node.

The purpose of the present invention is: in order to solve the drawbacks of ATM+IP overlapping network construction and design a kind of asynchronous transmission mode and the method for internet protocol superposition network construction, in a broadband multi-service switch equipment, by adopting original "one machine double "Plane" technology successfully solves the shortcomings of ATM+IP overlapping network construction, and at the same time simplifies network management, reduces network construction costs, and solves the bottleneck of business interoperability between the two networks, providing operators with a simple, reliable, and low-cost single-machine dual-service solution.

The technical solution for realizing the purpose of the present invention is as follows: a method for superimposing asynchronous transmission mode and Internet protocol to build a network is characterized in that: in the same broadband multi-service switch, with a unified switching network, the asynchronous Transfer mode (ATM) switching and high-speed Internet protocol (IP) routing switching, and intercommunication between asynchronous transfer mode (ATM) services and Internet protocol (IP) services.

A unified exchange network described includes setting an asynchronous transfer mode (ATM) service plane, a high-speed Internet protocol (IP) service plane, a unified core exchange platform, a pair of asynchronous transfer mode (ATM) service and high-speed The intercommunication function module for information exchange of Internet protocol (IP) services, the control module for controlling the asynchronous transfer mode (ATM) service plane and the control module for controlling the high-speed Internet protocol (IP) service plane, and the asynchronous transfer mode (ATM) service plane. Multi-Protocol Signature Switching (MPLS) control module for unified control of Transport Mode (ATM)/Internet Protocol (IP) services.

The simultaneous realization of asynchronous transfer mode (ATM) switching and high-speed Internet protocol (IP) routing switching further includes: receiving asynchronous transfer mode (ATM) cells from physical ports by the broadband multi-service switch, through the described Asynchronous transfer mode (ATM) service plane processing and under the control of the asynchronous transfer mode (ATM) control module or multi-protocol sign switching (MPLS) control module, after queue scheduling, it is sent to the core switching platform, and the core switching platform switches to the corresponding The asynchronous transfer mode (ATM) port realizes the asynchronous transfer mode (ATM) switch function; Receives the Internet protocol (IP) packet from the physical port by the described broadband multi-service switch, through the described high-speed Internet protocol (IP) Service plane processing and under the control of the high-speed Internet Protocol (IP) control module or the multi-protocol sign exchange (MPLS) control module, after queue scheduling, send to the described core switching platform, and then switch to the corresponding The international Internet protocol (IP) output port realizes the Internet protocol (IP) routing function.

Described realization asynchronous transfer mode (ATM) exchange function further comprises: receive asynchronous transfer mode (ATM) cell from asynchronous transfer mode (ATM) physical layer; Asynchronous transfer mode (ATM) cell is made asynchronous transfer mode ( ATM) layer processing; Asynchronous transfer mode (ATM) queue is managed and dispatched and then sent to the described core switching platform for switching; exchanged by the described core switching platform and sent to the corresponding asynchronous transfer mode (ATM) output port; Asynchronous transfer mode (ATM) queues are managed and scheduled, and then sent to the asynchronous transfer mode (ATM) layer for processing; and, outputting asynchronous transfer mode (ATM) cells from the physical port.

The described realization of the Internet Protocol (IP) routing function further includes: the Internet Protocol (IP) packet received is processed at the Internet Protocol (IP) layer; after being managed and dispatched by the Internet Protocol (IP) queue, it is sent to the The above-mentioned core switching platform is exchanged; Switched to the corresponding Internet Protocol (IP) output port by the described core switching platform; After the Internet Protocol (IP) queue management and scheduling, it is sent to the Internet Protocol (IP) layer for processing ; and, output Internet Protocol (IP) packets from the physical port.

The core switching platform adopts uniform fixed-length data packets for Asynchronous Transfer Mode (ATM) business and Internet Protocol (IP) business; and adopts unified packet encapsulation and unified queue management and scheduling.

The format of the unified fixed-length data packet comprises the format of Asynchronous Transfer Mode (ATM) business fixed-length data packet and the format of Internet Protocol (IP) business fixed-length data packet; Asynchronous Transfer Mode (ATM) business fixed-length data The format of the package is an internal data packet header of K bytes + 53 bytes of asynchronous transfer mode (ATM) cell header and asynchronous transfer mode (ATM) payload + M bytes of extension bits; Internet Protocol (IP) service definition The format of the long data packet is an internal data packet header of K bytes + an Internet Protocol (IP) packet message of N bytes + an extension bit of L bytes.

The K, M, N, L are positive integers less than 53, and the length of the unified fixed-length data packet is K+53+M=68 bytes and K+N+L=68 bytes.

The intercommunication between the Asynchronous Transfer Mode (ATM) service and the Internet Protocol (IP) service includes the intercommunication from the Asynchronous Transfer Mode (ATM) service to the Internet Protocol (IP) service, and the intercommunication from the Internet Protocol (IP) service to the Internet Protocol (IP) service. Interworking of services to Asynchronous Transfer Mode (ATM) services.

The intercommunication from the asynchronous transfer mode (ATM) service to the Internet protocol (IP) service is that the data received by the asynchronous transfer mode (ATM) interface is uniformly exchanged to the intercommunication function module through the core exchange platform, and then forwarded by the intercommunication function module To the target Internet Protocol (IP) port; the intercommunication of the described Internet Protocol (IP) business to the Asynchronous Transfer Mode (ATM) business is that the data received by the Internet Protocol (IP) interface is uniformly exchanged to the The interworking function module forwards it to the target asynchronous transfer mode (ATM) port by the interworking function module.

The intercommunication function modules are expanded according to the intercommunication bandwidth requirements of Asynchronous Transfer Mode (ATM) and Internet Protocol (IP), and the expanded intercommunication function modules can be stacked, and intercommunication can be performed between the expanded intercommunication function modules operate.

The intercommunication from the ATM service to the Internet Protocol (IP) service further includes: receiving the ATM cell from the physical port by the broadband multi-service switch, through the asynchronous Transfer mode (ATM) service plane is processed and sent to described core switching platform after unified queue scheduling; Switch to described interworking function module by described core switching platform; In interworking function module, through asynchronous transfer mode (ATM) queue management and layer processing are assembled into an Internet Protocol (IP) packet; by the described intercommunication function module, according to the assembled Internet Protocol (IP) packet header, the routing table is searched to determine the Internet Protocol (IP) forwarded ) output port; then sent to the core switching platform after Internet Protocol (IP) layer processing and queue management, and switched to the corresponding Internet Protocol (IP) output port.

The intercommunication from the Internet Protocol (IP) service to the Asynchronous Transfer Mode (ATM) service further includes: receiving the Internet Protocol (IP) packet from the physical port by the broadband multi-service switch, and passing through the high-speed international Internet protocol (IP) service plane processing, after queuing and scheduling, is sent to the core exchange platform; switched to the interworking function module by the core exchange platform; in the intercommunication function module, through the Internet protocol (IP) queue After management and layer processing, search the routing table according to the Internet Protocol (IP) packet header, determine the forwarded Asynchronous Transfer Mode (ATM) output port; core switching platform, and switch to the corresponding asynchronous transfer mode (ATM) output port.

The technical scheme that realizes the object of the present invention can also be like this: a kind of asynchronous transmission mode and the method for internet protocol superposition network construction, it is characterized in that: be in the same broadband multi-service exchange, with a unified switching network, simultaneously Realize Asynchronous Transfer Mode (ATM) switching and high-speed Internet Protocol (IP) routing switching.

A unified switching network described includes setting an asynchronous transfer mode (ATM) service plane, a high-speed Internet protocol (IP) service plane, a unified core switching platform, respectively performing asynchronous transfer mode (ATM) service plane The control module for controlling, the control module for controlling the high-speed Internet Protocol (IP) service plane, and the multi-protocol sign switching (MPLS) control module for unified control of Asynchronous Transfer Mode (ATM)/Internet Protocol (IP) services .

The asynchronous transmission mode of the present invention and the method for superimposing the Internet protocol to build a network are the first to realize a network device-level fusion under the general trend of current network integration; the superposition of the asynchronous transmission mode and the Internet protocol of the present invention The method for building a network is to realize ATM switching and high-speed IP routing functions simultaneously by adopting a unified switching network in a broadband multi-service switch, and to provide intercommunication of ATM services and IP services in this broadband multi-service switch simultaneously, namely The "one machine, two planes" technology mentioned above.

It should be noted that: as the current telecom market mainly relies on IP and ATM networks to provide Internet services and broadband data services, operators are under great pressure to maintain the two networks. Multi-protocol signing switching (MPLS) makes people see The dawn of a unified operating network platform, but because the MPLS standard has not yet been finalized, the MPLS intercommunication of various manufacturers is not uniform, which makes it difficult for MPLS to have advantages in quality of service (QoS), virtual private network (VPN), traffic engineering, etc. Play out, and at this stage still use MPLS network instead of ATM network and IP network. Therefore, so far, it is not realistic to realize the integration of the entire network. The integration of the entire network not only has no advantages, but also brings many risks.

The present invention is aimed at the shortcomings of the current ATM+IP overlapping network construction mode. Under the existing technical environment, the first two types of service quality require the integration of the equipment level of the business. After the MPLS technology matures, it can gradually reach the network level. fusion.

The technology of the present invention will be further described below in conjunction with the embodiments and accompanying drawings.

Fig. 1 is a functional block diagram of ATM exchange business realization of the pure ATM solution.

Fig. 2 is a functional block diagram of implementing the high-speed router service of building a metropolitan area network by using a high-speed switching router.

Fig. 3 is the realization block diagram that utilizes ATM switchboard and high-speed router to overlap and build the scheme of the network.

Fig. 4 is a functional block diagram of the single-machine dual-service plane technology of the present invention.

Fig. 5 is a schematic diagram of the ATM/IP service fixed-length data packet format adopted by the present invention.

The descriptions of FIGS. 1 to 3 have been mentioned before, and will not be repeated here.

Referring to Fig. 4, the Radium 8750 stand-alone dual service plane technology that adopts the method for the present invention to be implemented is shown in the figure, comprising: setting an Asynchronous Transfer Mode (ATM) service plane 41, a high-speed Internet Protocol (IP) service plane 42, A unified core switching platform 43, an intercommunication function module 44 for information interworking between Asynchronous Transfer Mode (ATM) services and high-speed Internet Protocol (IP) services, and a control module for controlling the Asynchronous Transfer Mode (ATM) service plane respectively 451 and a control module 452 that controls the high-speed Internet Protocol (IP) service plane, and a multi-protocol sign switching (MPLS) control module 45 that uniformly controls Asynchronous Transfer Mode (ATM)/Internet Protocol (IP) services.

The asynchronous transfer mode (ATM) service plane 41 has the same realization principle as that of the ATM switch shown in FIG. 1 . Its input line interface unit comprises physical layer (PHY) 411, ATM layer processes 412 and ATM queue management 413, and physical layer (PHY) 411 extracts ATM cell from physical link; ATM layer processes 412 and extracts information from ATM cell The VPI/VCI value in the Yuan header, after querying the connection routing table, correspondingly generates the internal cell format (as adding internal cell encapsulation head Tag etc.) and carries out ATM flow monitoring; ATM queue management 413 carries out each virtual channel (per VC) queuing and scheduling by service category. Its output line interface unit comprises ATM queue management 414, ATM layer processing 415 and physical layer (PHY) 416, and ATM queue management 414 carries out output queuing; ATM layer processing 415 removes internal cell encapsulation head (Tag) and carries out cell header switching ; The physical layer (PHY) 416 sends ATM cells to the physical link.

The asynchronous transfer mode (ATM) service plane 41 can be controlled and managed by the ATM control module 452, and supports multi-protocol signing switching (MPLS) at the same time, providing a basis for the transition of the network to a unified MPLS network.

The high-speed Internet Protocol (IP) service plane 42 has the same realization principle as the high-speed routing service shown in FIG. 2 . The input units therein include physical layer (PHY) 421 , IP layer processing 422 and IP queue management 423 . The physical layer (PHY) 421 extracts the IP packet from the physical link through the POS/GE interface; the IP layer processing 422 performs RED, WFQ, CBQ (representing traffic monitoring strategies respectively) and other processing on the IP packet and cuts (splitting) the IP into pieces Process into fixed-length data packets, and perform Internet access control; IP queue management 423 extracts the destination IP address in the IP header, checks the routing table, classifies the IP flow, and monitors the IP flow. The output unit wherein includes IP queue management 424, IP layer processing 425 and physical layer (PHY) 426, IP queue management 424 carries out reorganization IP packet and output queuing to IP fragmentation; IP layer processing 425 finishes L3/L2 (IP network and The layer of Ethernet handles the encapsulation) address mapping; the physical layer (PHY) 426 sends the IP packet to the physical link through the POS/GE interface.

The high-speed Internet Protocol (IP) service plane 42 can be controlled and managed through the IP control module 451, and supports Multi-Protocol Signature Switching (MPLS) at the same time, providing a basis for the transition of the network to a unified MPLS network.

The unified core switching platform 43 is mainly manifested in that ATM services and IP services are exchanged using unified fixed-length data packets; both ATM service data cells and IP service data packets use unified packet encapsulation and unified queue management and scheduling.

The interworking function module (RFM) 44 includes ATM queue management 441 and ATM layer processing 442 for processing ATM services, IP queue management 443 and IP layer processing 444 for IP services, and an IP/ATM interworking function module 445 for realizing interworking functions.

When realizing the ATM service switching function: switch receives ATM cell from physical port 411, through ATM layer processing 412, ATM queue management 413, sends to unified core switching platform 43 after dispatching, sends to corresponding ATM port after switching (via ATM queue management 414, ATM layer processing 415 and physical layer 416). The format of the input ATM cell is a standard ATM cell: cell header (including VP/VCI) + 48 bytes of fixed-length data; the format of the internal exchange fixed-length packet is the internal header mark (such as Tag, etc.) + ATM cell ; The output ATM cell format is the cell header (including VPI'/VCI') + 48-byte fixed-length data.

When implementing the IP service routing function: the switch receives the IP data packet service from the physical layer 421, performs fragmentation processing and cuts into fixed-length data packets (422), sends them to the IP queue management (423), and sends them to the unified The core switching platform 43 sends the switching to the corresponding IP port (via IP queue management 424, IP layer processing 425 and physical layer 426). The format of the input IP packet is IP header + variable-length IP payload; the format of the internal exchange fixed-length packet is internal header mark (such as Tag, etc.) + IP fragmentation; the output IP packet format is IP header + variable-length IP payload.

When realizing the intercommunication from ATM service to IP service: the data received from the ATM interface, after physical layer 411, ATM layer processing 412 and ATM queue management 413, is sent to the unified core switching platform 43 after dispatching, and is exchanged through the core switching platform 43 Send to intercommunication function module 44 after; Through ATM queue management 441, do output queuing and ATM layer processing 442 and assemble into IP data packet, IP/ATM intercommunication function module 445 searches routing table according to the IP data packet header after assembling, determines the output port of forwarding Carry out address mapping, reorganization IP packet and output queuing through IP layer processing 425 and IP queue management 424 again, send to unified core exchange platform 43, after promptly forwarding through intercommunication function module (RFM), forward to corresponding target IP port (via IP queue management 423, IP layer processing 422 and physical layer 421). The format of the input ATM cell is cell header (including VP/VCI) + 48 byte fixed-length data; the format of the internal exchange fixed-length packet is the internal flag header (such as Tag, etc.) + ATM cell; the output IP packet format is IP header + variable length IP payload.

When realizing the intercommunication from IP service to ATM service: the data received from IP interface, after physical layer 421, IP layer processing 422 and IP queue management 423, is sent to unified core switching platform 43 after scheduling, and is exchanged by core switching platform 43 Sent to intercommunication function module 44 after; Process 444 through IP queue management 443 and IP layer and do recombination IP packet, output queuing and address mapping, IP/ATM intercommunication function module 445 searches routing table according to the IP packet header after assembling, determines the forwarding ATM connection port; then through ATM layer processing 442 and ATM queue management 441, remove internal cell encapsulation header, cell header switching and output queuing, and send to unified core switching platform 43, that is, after forwarding by interworking function module (RFM) , forward to the corresponding target ATM port (via ATM queue management 413, ATM layer processing 412 and physical layer 411), and encapsulate the IP packet in the ATM cell. The format of the input IP packet is IP header + variable-length IP payload; the format of the internal exchange fixed-length packet is the internal header mark (such as Tag, etc.) + fixed-length data packet (IP fragmentation); the format of the output ATM cell is ATM letter Header (including VPI'/VCI') + 48-byte fixed-length data.

In a nutshell, to realize the intercommunication between IP service and ATM service, the data received from the ATM interface is sent to the intercommunication function module 44 after being exchanged by the core switching platform 43, and forwarded to the corresponding IP target port after being forwarded by the intercommunication function module 44; The data received from the IP interface is exchanged by the core switching platform 43 and sent to the intercommunication function module 44, and forwarded by the intercommunication function module 44 to the corresponding ATM target port.

Therefore, in the switch, the intercommunication between the ATM service and the IP service needs to be realized through an internal intercommunication function module (RFM) 44 .

The unified core switching platform is mainly manifested in that both ATM and IP services are exchanged using unified fixed-length data packets. As in the Radium 8750 device of the embodiment, the fixed-length data packets are long as 68 bytes (Byte). The format of the ATM/IP service fixed-length data packet is shown in FIG. 5 .

The intercommunication function module (RFM) can be expanded according to the intercommunication bandwidth, each RFM can be stacked, and each RFM can intercommunicate. The interworking function module (RFM) mainly completes the three-layer forwarding function, and maintains a dynamic routing table on each RFM. RFM mainly completes: between ATM interface boards, IP over ATM (IP OVERATM) is used to complete IP routing and forwarding; between ATM interface boards and IP service interface boards, IP routing and forwarding are completed.

The present invention simultaneously sets two planes in one switch: ATM plane and IP plane. IP routing distributed line-speed forwarding is realized by the POS/GE and other IP service interface boards carried on the IP plane. Its forwarding mode, forwarding efficiency, routing protocol and routing backup mechanism are exactly the same as those of GSR equipment, which can meet the requirements of best-effort transmission of a large number of Internet services. At the same time, its flow classification, queuing, caching, and scheduling mechanisms can meet certain IP service quality ensure. The IP business carried on the ATM plane can enjoy luxury services, through the precise and perfect flow control, congestion control, delay guarantee and other service quality assurance mechanisms provided by ATM, to provide distinctive differentiated services to business users, with standard ATM The switch has all functions.

In the application of pure ATM plane or pure IP plane switching, the present invention does not need to be equipped with an intercommunication function module (RFM), and can improve the economical efficiency of equipment. The RFM module needs to be set only when the ATM plane and the IP plane communicate with each other and IP OVERATM is used to realize IP routing and forwarding. Due to the powerful forwarding performance and stackable features of RFM, it is ensured that the entire device can realize IP line-speed transmission between any ports no matter which plane carries IP.

Referring to Fig. 5, for the unified core switching platform 43, ATM cells and IP data packets adopt unified internal exchange fixed-length grouping in the switching network: the internal data packet header Tag+ATM cell/IP data fragmentation of K bytes; The ATM cell is composed of 53-byte ATM cell header plus ATM payload and M-byte extension bits; the IP data fragment is composed of N-byte IP packet message plus L-byte extension bits . K, M, N, L are positive integers less than 53, and K+53+M=68, K+N+L=68.

In the present invention, allow the length of the internal packet of ATM service and IP service to be consistent, as all be 68 BYTE. In the technology of the present invention, the fragmentation of the IP packet is different from the traditional IPOA (IP OVER ATM) mode. The traditional approach is to encapsulate IP packets in the payload of ATM cells. However, the "one machine double plane" technology of the present invention directly encapsulates the IP packet in the internal data packet, which can overcome the low efficiency of the traditional IPOA method, greatly improve the forwarding rate of the data packet, and make all IP interfaces line speed can be achieved.

The "one machine, two planes" technology adopted in the present invention can overcome the shortcomings of traditional network solutions, and can efficiently process best-effort IP services as well as services that require service quality assurance. Using switches designed with "one machine, two planes" to build an ATM+IP network does not need to build an ATM network and an IP network separately, which simplifies the network structure and greatly reduces construction costs and investment risks. In terms of network management, it overcomes the disadvantage that the traditional IP+ATM network needs to manage the ATM plane and IP plane separately, and only needs to manage the same device, which greatly simplifies the network management. In terms of dual-plane intercommunication efficiency, the traditional ATM+IP overlapping network construction mode can only interconnect two independent physical networks through an ATM or POS port, and there is a bottleneck problem in the IP transfer rate between the two networks. However, when a switch using "one machine, two planes" technology is used to build a network, the IP transmission between the two service planes is completed through the core switching platform in the device, and there is no bottleneck problem between port rates, that is, in any core On the node, these two networks can all exchange the seamless intercommunication, have solved the integration problem of ATM network and IP network well actually.

Claims (15)

1. A method for asynchronous transfer mode and Internet protocol superposition network construction is characterized in that: in the same broadband multi-service switch, with a unified switching network, realize asynchronous transfer mode (ATM) exchange and high-speed international simultaneously Internet Protocol (IP) routing switching, and intercommunication between Asynchronous Transfer Mode (ATM) services and Internet Protocol (IP) services. 2. a kind of asynchronous transfer mode according to claim 1 and the method for internet protocol superposition network construction, it is characterized in that: described a unified switching network comprises setting an asynchronous transfer mode (ATM) service plane, a High-speed Internet Protocol (IP) service plane, a unified core switching platform, an intercommunication function module for information interworking between Asynchronous Transfer Mode (ATM) services and high-speed Internet Protocol (IP) services, and asynchronous transfer mode (ATM ) business plane control module, a control module for high-speed Internet Protocol (IP) business plane control, and a multi-protocol sign exchange ( MPLS) control module. 3. a kind of asynchronous transfer mode according to claim 1 and 2 described and the method for internet protocol superposition network construction, it is characterized in that: described simultaneously realizes asynchronous transfer mode (ATM) exchange and high-speed internet protocol (IP) Routing switching, further comprising: receiving an asynchronous transfer mode (ATM) cell from a physical port by the broadband multi-service switch, processing through the asynchronous transfer mode (ATM) service plane and in an asynchronous transfer mode (ATM) control module Or under the control of the multi-protocol sign exchange (MPLS) control module, it is sent to the core switching platform after queue scheduling, and is switched to the corresponding asynchronous transfer mode (ATM) port by the core switching platform to realize the asynchronous transfer mode (ATM) switch function; Described broadband multi-service exchange receives Internet protocol (IP) packet from physical port, processes through described high-speed Internet protocol (IP) business plane and in high-speed Internet protocol (IP) control module or multi-protocol sign exchange ( Under the control of MPLS) control module, send to described core switching platform after queue dispatching, switch to corresponding Internet Protocol (IP) output port by described core switching platform, realize Internet Protocol (IP) routing function. 4. a kind of asynchronous transfer mode according to claim 3 and the method for internet protocol overlay network construction, it is characterized in that described realization asynchronous transfer mode (ATM) switch function further comprises: from asynchronous transfer mode (ATM) physical Layer receives asynchronous transfer mode (ATM) cell; Asynchronous transfer mode (ATM) cell is processed by asynchronous transfer mode (ATM) layer; Asynchronous transfer mode (ATM) queue is managed and dispatched and then sent to the The core switching platform is switched; the core switching platform is switched and sent to the corresponding asynchronous transfer mode (ATM) output port; the asynchronous transfer mode (ATM) queue is managed and dispatched and sent to the asynchronous transfer mode (ATM) layer for processing ; and, output an asynchronous transfer mode (ATM) cell from the physical port. 5. a kind of asynchronous transfer mode according to claim 3 and the method for internet protocol superposition network construction, it is characterized in that described realization internet protocol (IP) routing function further comprises: to the received internet protocol (IP ) is packaged as the Internet Protocol (IP) layer processing; after the Internet Protocol (IP) queue management and scheduling, it is sent to the described core exchange platform for exchange; it is switched to the corresponding Internet Protocol (IP) by the described core exchange platform IP) output port; sent to the Internet Protocol (IP) layer for processing after being managed and dispatched by the Internet Protocol (IP) queue; and, outputting the Internet Protocol (IP) packet from the physical port. 6. according to claim 4 or 5 described a kind of asynchronous transfer mode (ATM) business and the method for internet protocol (IP) superposition, it is characterized in that: described core exchange platform is to asynchronous transfer mode (ATM) business and internet protocol ( IP) services are exchanged with unified fixed-length data packets; and unified packet encapsulation and unified queue management and scheduling are adopted. 7. a kind of asynchronous transfer mode according to claim 6 and the method for internet protocol superposition network construction are characterized in that: the format of the unified fixed-length data packet comprises asynchronous transfer mode (ATM) service fixed-length data The format of the packet and the format of the Internet Protocol (IP) service fixed-length data packet; the format of the asynchronous transfer mode (ATM) service fixed-length data packet is the internal data packet header of K bytes + 53 bytes of asynchronous transfer mode (ATM) Cell header and asynchronous transfer mode (ATM) payload+M byte extension; the format of the Internet Protocol (IP) service fixed-length data packet is the internal data packet header of K byte+N byte Internet protocol ( IP) packet message + L byte extension bit. 8. A method for building a superimposed network based on asynchronous transfer mode and Internet protocol according to claim 7, characterized in that: said K, M, N, L are positive integers less than 53, and a unified fixed-length The length of the data packet is K+53+M=68 bytes and K+N+L=68 bytes. 9. according to claim 1 or 2 described a kind of method of asynchronous transfer mode and Internet protocol superposition network construction, it is characterized in that: described carry out asynchronous transfer mode (ATM) service and Internet protocol (IP) service Interworking, including interworking from Asynchronous Transfer Mode (ATM) services to Internet Protocol (IP) services, and interworking from Internet Protocol (IP) services to Asynchronous Transfer Mode (ATM) services. 10. A kind of ATM and the method for Internet Protocol overlay network construction according to claim 9, it is characterized in that: described intercommunication from ATM (ATM) service to Internet Protocol (IP) service is The data received by the Asynchronous Transfer Mode (ATM) interface is uniformly exchanged to the intercommunication function module through the core exchange platform, and then forwarded to the target Internet Protocol (IP) port by the intercommunication function module; The intercommunication of asynchronous transfer mode (ATM) service is to uniformly exchange the data received by the Internet protocol (IP) interface to the interworking function module through the core switching platform, and then forward it to the target asynchronous transfer mode (ATM) port by the interworking function module. 11. a kind of asynchronous transfer mode according to claim 10 and the method for internet protocol superimposed network construction, it is characterized in that: described intercommunication function module is according to asynchronous transfer mode (ATM) and internet protocol (IP) If the intercommunication bandwidth needs to be expanded, the expanded intercommunication function modules can be stacked, and the intercommunication function modules can be interoperated. 12. A kind of method for asynchronous transfer mode and internet protocol superposition network construction according to claim 9, it is characterized in that described intercommunication from asynchronous transfer mode (ATM) business to internet protocol (IP) business further comprises : the broadband multi-service switch receives an asynchronous transfer mode (ATM) cell from a physical port, and sends it to the core switching platform after being processed by the asynchronous transfer mode (ATM) service plane and unified queue scheduling ; Switched to the described interworking function module by the described core exchange platform; In the interworking function module, after asynchronous transfer mode (ATM) queue management and layer processing, it is assembled into an Internet Protocol (IP) packet; by the described The intercommunication function module searches the routing table according to the assembled Internet Protocol (IP) packet header, and determines the forwarded Internet Protocol (IP) output port; then sends to the described The core switching platform is switched to the corresponding Internet Protocol (IP) output port. 13. A kind of method for asynchronous transfer mode and internet protocol overlay network construction according to claim 9, it is characterized in that described intercommunication from internet protocol (IP) service to asynchronous transfer mode (ATM) service further comprises : receive the Internet Protocol (IP) packet from the physical port by the broadband multi-service switch, and send it to the core exchange platform after the described high-speed Internet Protocol (IP) business plane processing, queuing and dispatching; by the described The core switching platform is switched to the interworking function module; in the interworking function module, after Internet Protocol (IP) queue management and layer processing, the routing table is searched according to the Internet Protocol (IP) packet header to determine the asynchronous forwarding Transfer mode (ATM) output port; Send to described core exchange platform after ATM layer processing and queue management again, and switch to corresponding Asynchronous transfer mode (ATM) output port. 14. A method for asynchronous transfer mode and Internet protocol superposition network construction, characterized in that: in the same broadband multi-service switch, with a unified switching network, simultaneously realize asynchronous transfer mode (ATM) switching and high-speed international Internet Protocol (IP) routing switching. 15. the method for a kind of asynchronous transfer mode and internet protocol overlay network construction according to claim 14, is characterized in that: described a unified exchange network comprises setting an asynchronous transfer mode (ATM) service plane, an a high-speed Internet Protocol (IP) service plane, a unified core switching platform, a control module for controlling the Asynchronous Transfer Mode (ATM) service plane and a control module for controlling the high-speed Internet Protocol (IP) service plane, and Multi-Protocol Signature Switching (MPLS) control module for unified control of Asynchronous Transfer Mode (ATM)/Internet Protocol (IP) services.

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