Exchange transmits the method and the device of ATM business based on IP
Technical field
The present invention relates to network communications technology field, relate in particular to a kind of method and device based on IP exchange transmission ATM business.
Background technology
Evolution from ATM (asynchronous transfer mode) to the IP transmission means is the development trend of present access device, in evolution, needs to take into account the existing investment of protection operator simultaneously, promptly makes the IP access device can insert original ATM access device.For this reason, how to support to be up to atm network, and professional how the realization on IP DSLAM (IP Digital Subscriber Line Access Multiplexer) of TDM (time division multiplexing) that original ATM supports supporting, is the subject matter that present IP access device need solve.
When considering atm interface, IP access device frame structure is generally the framework based on IP, as shown in Figure 1, described IP access device form extensive gradually along with what use, increased the atm interface of network side on the interface shape, atm interface can insert ATM access device or ATM private line service, still, because the switching system in the IP access device is to realize based on IP, thereby cause its support difficult relatively to atm interface.
The transmission of ADSL (ADSL (Asymmetric Digital Subscriber Line)) and ATM E1/E3 interface be the ATM cell data, and that the up going port of IP access device might be FE (Fast Ethernet)/GE (gigabit Ethernet) mouthful IP is up, the ATM that also might be ATM E1/E3 is up, through described switching system, ATM just needs the complex process of process ATM-IP-ATM to the connection support of ATM, and each user of this processing needs a MAC (medium access control) address, and the MAC Address of switching system is had very big demand; The whole process need of ATM-IP-ATM is handled through SAR (burst and reorganization), and the complete transmission of atm information is difficulty relatively, and the SAR function that need support when supporting AAL1 and AAL2 has increased intractability with regard to more complicated.
Except network side atm interface demand, as shown in Figure 2, be a kind of mainstream applications technology in early days, so many Network Convergence Layers of present operator or the professional equipment of employing that is based on ATM because atm technology inserts at DSL.At this moment, if be to be linked into the ATM business device to use from ATM access device ATM DSLSM (ATM Digital Subscriber Line Access Multiplexer) or ADSL terminal, then the IP access device can't be supported this application at present.Therefore, coming into operation of IP access device also needs to consider support at above-mentioned situation.
For adapting under the above-mentioned applied environment, the IP access device needs to support the professional transmission of ATM.For this reason, industry has adopted various implementations to achieve the above object in application process respectively at present.
At present a kind of mode that adopts is: based on the IP access device of multibus, and promptly by providing ATM and IP bus to hang the ATM access device under supporting on the IP access device simultaneously, and the ATM upstream Interface.Up ATM business is walked the ATM bus, and cell can be from user interface directly to network interface like this.
As can be seen, the multibus technology can solve the up problem of ATM well, yet, it is for but not improving (described ATM service application is meant that the ATM service needed arrives the ATM business device via IP access device and IP metropolitan area network) in the up ATM service application support of IP, and when using for IP and ATM mix of traffic, especially one has part A TM business on the extension atm device down, when the part IP operation is arranged again, then because ATM bus and IP bus are physical isolation, at this moment, the multibus scheme just can't realize that inferior position is also just apparent altogether by the mechanism of bus allotment flexibly.
The another kind of implementation that adopts is at present: based on the equipment of IP switching system, for user interface, no matter be ADSL or atm interface, the unified ethernet frame that reassembles into, behind the IP switching system, handle according to the network interface form in the exit, the FE/GE interface directly sends Ethernet, and atm interface need carry out burst once more to be handled.The processing of returning from network side too.
In this scheme, because the entrance and exit at the IP access device all may need message is carried out complicated reorganization and burst processing, cost and the complexity handled are all bigger, and ATM also need transmit at each user's configuration on the IP switching system when up, waste system resource increases system burden.And the diversity of consideration ATM traffic format, atm information is lost in reorganization and section easily.In addition, use, and up going port can't be accomplished on the complete ATM of the being delivered to service application of the atm information equipment when being the FE/GE interface at IP and ATM mixed service.
Another problem that above-mentioned second kind of implementation obviously exists is exactly that autgmentability is not strong, in case the cell internal form changes, reorganization or section can't be supported, will cause the ATM business to carry out.
Summary of the invention
In view of above-mentioned existing in prior technology problem, the purpose of this invention is to provide a kind of method and device based on IP exchange transmission ATM business, thereby make the transmission that on the IP access device, can support the ATM business flexibly, easily, and realize simple, simultaneously, the present invention can also be applicable to the situation that the mix of traffic of IP and ATM is used.
The objective of the invention is to be achieved through the following technical solutions:
The invention provides a kind of method, comprising based on IP exchange transmission ATM business:
In the network of the professional coexistence of IP operation and asynchronous transfer mode ATM, need at first carry out encapsulation process via the ATM business that the IP exchange is handled based on Ethernet protocol, afterwards, handle and send through the IP exchange again.
Method of the present invention specifically comprises:
A, in needs carry out business that IP exchange handles, identify and need the asynchronous transfer mode ATM of transparent transmission business;
B, described ATM business is carried out encapsulation process based on Ethernet protocol, handle and send through the IP exchange again.
Among the present invention, when carrying out IP exchange processing by the IP access device, described steps A comprises:
Up direction at the IP access device, upstream Interface and/or link information according to the ATM business that receives judge whether it is the ATM business of needs transparent transmission, if and upstream Interface is an atm interface or when connecting for Permanent Virtual Channel PVC, then for needing the ATM business of transparent transmission.
Among the present invention, when carrying out IP exchange processing by the IP access device, described steps A comprises:
At the down direction of IP access device, judge whether ATM business according to receiving professional interface, and if receive professional to be atm network interface, should business to be the ATM business that needs transparent transmission then into the needs transparent transmission.
Described step B comprises:
Ethernet header, link information, type of message information and/or standard ethernet check information are gone up in the professional encapsulation of the ATM that needs transparent transmission, and sent.
Described step B also comprises:
Will be through based on the Ethernet encapsulation process, and through IP the frame after exchange is handled carries out handling based on the decapsulation of Ethernet protocol, and send.
Among the present invention, when carrying out IP exchange processing by the IP access device, described step B also comprises:
At the up direction of IP access device, be message with not needing the business reorganization of transparent transmission, and send after being encapsulated as ethernet frame;
The IP access device has carried out the exchange processing to sent message after, judge whether for needs by atm interface up, if, send after then will peeling off encapsulation process through the frame after the Ethernet encapsulation, with other ethernet frame bursts is to send after the ATM cell, otherwise, directly transmit corresponding message.
Among the present invention, when carrying out IP exchange processing by the IP access device, described step B also comprises:
At the down direction of IP access device, will not need the business of transparent transmission directly to send processing;
After in the IP access device, having carried out exchange and handle, judge whether to be frame, if send after then peeling off encapsulation process, otherwise the ethernet frame burst is to send after the ATM cell through after the Ethernet encapsulation to sent message.
The present invention also provides a kind of device based on IP exchange transmission ATM business, comprising:
Recognition processing module: be used for carrying out upstream or downstream business that IP exchange handles and identify and to carry out, and transfer to Ethernet package module or Ethernet decapsulation module based on the encapsulation process of Ethernet protocol or the business of handling based on the decapsulation of Ethernet protocol at needs;
Ethernet package module: corresponding business is carried out encapsulation process based on Ethernet protocol, and send to and be responsible for the module that the IP exchange is handled;
Ethernet decapsulation module: corresponding business is carried out handling based on the decapsulation of Ethernet protocol, peel off its Ethernet encapsulation, and send.
Device of the present invention can be arranged in the IP access device.
As seen from the above technical solution provided by the invention, the present invention realizes the support of ATM business by a kind of simple AOE (based on the ATM of Ethernet) encapsulation technology on the IP access device.Specifically comprise: support the ATM business interface, the support atm network interface, and support ATM business interface, IP and atm network interface to coexist simultaneously, and in addition, can also support through docking with the ATM business device behind the IP metropolitan area network, support to mix application at IP and ATM.
The AOE technology realizes simple, and autgmentability is strong, and protection ATM access device and the investment of ATM business device.Can fine support IP in IP network is transformed and the mix of traffic networking of ATM at ATM, insert the ATM access device simultaneously to the IP metropolitan area network.
Description of drawings
Fig. 1 is the structural representation of IP access device;
Fig. 2 uses networking diagram based on the IP of IP access device and ATM service integration;
Fig. 3 is a up processing procedure schematic diagram in the method for the present invention;
Fig. 4 is a downlink processing process schematic diagram in the method for the invention;
Fig. 5 is the structural representation of device of the present invention.
Embodiment
Still with reference to shown in Figure 2, the up employing of IP access device IP DSLAM (IP Digital Subscriber Line Access Multiplexer) network side ATM, Ethernet or MPLS all can.Use if be linked into the ATM business device from ATM access device ATM DSLSM (ATM Digital Subscriber Line Access Multiplexer) or ADSL terminal, just PVC (permanent virtual connection) information lossless need be transparent to the opposite end atm device, also need from the ATM business device to user side equally to handle.
For this reason, the invention provides a kind of AOE (based on the ATM of Ethernet) technology, can be implemented in by this AOE technology and support on the IP access device to hang the ATM access device down, ATM is up, and IP and ATM mix of traffic are used.Can reduce the intractability and the cost of equipment, the PVC information lossless is delivered to professional opposite end, for professional following expansion provides possibility.
AOE technology of the present invention is mainly: with the ATM cell of the user interface of ATM upstream Interface or ATM service application directly be carried on the Ethernet through behind the IP switching system of IP access device in the exit or ATM business device porch peel off the Ethernet encapsulation and directly revert to ATM cell, like this, just can simple and conveniently reach the application of hanging ATM and ATM upstream Interface under realizing, and do not need to understand the inner bear format of cell, favorable expandability.IP operation for the IP interface is used, and then is to transmit from FE/GE after the porch is reassembled as ethernet frame process IP switching system.
For the present invention there being further understanding, will describe application below in detail based on AOE.
Described AOE is a kind of technology that directly ATM cell is packaged into ethernet frame, and the AOE frame format after the encapsulation is as shown in table 1:
Table 1
Data field | Explanation |
The Ethernet frame head | The standard ethernet frame head comprises DMAC/SMAC/VLAN etc., and DMAC/SMAC need be at subscriber segmentation during AOE, and every block of one of plate also can be realized; |
The AOE type field | Explanation is the sign of AOE form, can a self-defined numerical value, be equivalent to the ethernet type field |
Inner connecting strand quotation marks | Mainly be to carry some link informations, be generally PVC link information and label information, length and form can be self-defined |
ATM cell | The complete transmission of ATM cell or remove the part for example the HEC territory all be fine |
Fill | Can be with or without, length also is not specifically limited |
FCS | The standard ethernet verification |
Can on the IP access device, realize transparent transmission based on the AOE frame format shown in the table 1, and the entire process process realizes simple at ATM cell.
The present invention is in concrete application process, on the IP access device, mainly comprise by user side and will be described in detail two kinds of processing procedures respectively below to the processing of the up direction of network side with by the processing of network side to the down direction of user side at the processing of ATM business.
At first, when business by user side during to network side, corresponding processing procedure specifically comprises following treatment step as shown in Figure 3:
Step 31: judge whether the type of service on the user interface needs to carry out the business of AOE encapsulation, if then execution in step 32, otherwise, execution in step 33;
Be specially: handle for the application from the user interface to the network interface, judge the customer service type at the user interface place according to PVC or port, if up atm interface or ATM service application, whereabouts that promptly should business is atm network or atm device, and then being defined as by the business on the user interface is the business that need carry out the AOE encapsulation;
Step 32: the AOE message format shown in the employing table 1 carries out encapsulation process with ATM cell, and execution in step 35;
The hyphen that link information adopts the PVC hyphen or tables look-up and obtain, DMAC (purpose MAC) address is the up going port MAC Address, SMAC (source MAC) can distinguish based on the user address, also can one one of veneer;
Step 33: if other service application, promptly non-ATM service application then is reassembled as message with cells such as corresponding ATM;
Step 34: the message of described reorganization is converted to common ethernet frame according to the ATM encapsulated type;
Step 35: on the IP access device, corresponding ethernet frame or AOE frame are passed through the IP switching system to the network side interface, described IP switching system can be thought an ethernet switching device;
Step 36: judge whether to up through atm network interface, if then execution in step 37, otherwise, execution in step 38;
Whether the whereabouts of just judging described business is the ATM business device that directly is connected with the IP access device, if then execution in step 37, otherwise, execution in step 38;
Step 37: if determine and need transmit, then further judge whether to AOE frame through the ATM upstream Interface, if then execution in step 39, otherwise, execution in step 310;
Step 39: directly peel off the Ethernet encapsulation of AOE, directly send after getting the ATM cell data;
Step 310: with the ethernet frame burst is to send after the ATM cell, and the purpose of this processing is and existing processing procedure compatibility.
Step 38: if specified data need be transmitted through FE/GE class IP upstream Interface, then directly E-Packet, what difference only was the transmission of ATM service application is the AOE frame, and what IP operation was transmitted then is common ethernet frame;
The AOE frame of described ATM service application will obtain original ATM cell receiving the processing of peeling off its ether encapsulation on this professional opposite end corresponding apparatus.
Again to describing, as shown in Figure 4, specifically comprise following treatment step below by the Business Processing process of network side to user interface side:
Step 41: judge by network side whether the network side input interface is atm network interface in the processing procedure of user interface, if then execution in step 42, otherwise, direct execution in step 43;
Step 42: if the network side input interface is an atm network interface, then cell is packaged into ethernet frame according to the AOE form, execution in step 43;
Step 43: the data of network side input are exchanged to transmit handle, be specially to the data message carry out IP or and the net exchange handle;
That is, transmit, transmit if the data of atm network interface input then need to carry out the ethernet frame exchange after step 42 is handled if the data of FE/GE IP interface input are then directly carried out the IP exchange;
Step 44: pass through IP and exchange when handling afterwards to user interface, judge then whether described message is the AOE frame, is specially according to the ethernet type field and judges whether the AOE frame, if then execution in step 45, otherwise, execution in step 46;
Step 45: if exchange to the message of user interface is the AOE frame, then peels off Ethernet head taking-up hyphen and ATM cell and directly transmits;
Can be through this step with AOE frame in local terminal encapsulation, and the AOE frame that comes by the transmission of IP network interface all is treated to original ATM cell, and send to user side;
Step 46: if ethernet frame just carries out sending to user side after burst is handled, being specially the ethernet frame burst is to send processing after the ATM cell.
In a word, the present invention's processing procedure that AOE realizes on the IP access device comprises that AOE still is the judgement that common ethernet frame is handled, and concrete frame format and bit field field can be self-defined, also can handle according to standard, and the present invention does not do concrete qualification.And; in actual process; the AOE technology that the present invention adopts may no longer be the title of AOE; but it is mainly handled to be and cell is not recombinated but directly is packaged into independent ethernet frame one by one; as long as adopt this processing mode to realize IP access device support ATM business, then all should be within protection range of the present invention.
The present invention also provides a kind of device in IP access device transmission ATM business, and as shown in Figure 5, this device specifically comprises:
Recognition processing module: be used for identifying the business that to carry out Ethernet encapsulation process or Ethernet decapsulation processing, and transfer to Ethernet package module or Ethernet decapsulation module in upstream or downstream business via the IP access device;
Ethernet package module: corresponding business is carried out the Ethernet encapsulation process, and the sending module of giving in the IP access device sends (sending module is an existing module in the IP access device), and the AOE frame format shown in can employing table 1 in this module is carried out the Ethernet encapsulation process;
Ethernet decapsulation module: corresponding business is carried out the Ethernet decapsulation handle, promptly business is peeled off the processing of its Ethernet encapsulation, and transfer to sending module and send.
In sum, the present invention realizes supporting the ATM business by a kind of simple AOE encapsulation technology on the IP access device.And described AOE technology realizes simple, and autgmentability is strong, can effectively protect the investment of ATM access device and ATM business device.Can fine support IP in IP network is transformed and the mix of traffic networking of ATM at ATM, insert the ATM access device simultaneously to the IP metropolitan area network.
The above; only for the preferable embodiment of the present invention, but protection scope of the present invention is not limited thereto, and anyly is familiar with those skilled in the art in the technical scope that the present invention discloses; the variation that can expect easily or replacement all should be encompassed within protection scope of the present invention.Therefore, protection scope of the present invention should be as the criterion with the protection range of claim.