CN100550756C

CN100550756C - A kind of method that on the SPI4.2 bus, realizes multicast

Info

Publication number: CN100550756C
Application number: CNB2006101141765A
Authority: CN
Inventors: 王振峰; 翟红健
Original assignee: ZTE Corp
Current assignee: ZTE Corp
Priority date: 2006-10-31
Filing date: 2006-10-31
Publication date: 2009-10-14
Anticipated expiration: 2026-10-31
Also published as: CN101174964A

Abstract

The invention discloses a kind of method that on the SPI4.2 bus, realizes multicast, be used for payload being sent at least one port in a data transfer, comprise step: payload control word group is set before described payload, described payload control word group comprises at least one payload control word, and each described payload control word has a port address; Above-mentioned payload is copied on the described port.

Description

A kind of method that on the SPI4.2 bus, realizes multicast

Technical field

The present invention relates to multicasting technology, particularly on bus, realize the method for multicast.

Background technology

SPI4.2 bus (System Packet Interface Level 4 Phase 2BUS, 4 grade of 2 phase place bus of system's packet interface) be OIF (Optical Internetworking Forum, optical interconnection network forum) a kind of bus standard of Zhi Dinging, be applied in the bus interface between data link layer and the physical layer, its bandwidth can reach 10Gb/s.Adaptable physical interface has OC-192ATM, Packet over SONET/SDH (POS), 10Gb/s Ethernet etc.Its system configuration wherein, receives with the data channel that sends and separates with flow control channel, and be reverse as shown in Figure 1.The separation of two passages is with regard to feasible reception and send separate.At receiving port and transmit port, the address of packet, descriptor and error control code be transmission in band.

The SPI4.2 bus has following characteristics: point-to-point connection (Point-to-point connection); Support 256 ports (port) at most; The data width of transmission/reception data channel is 16bit, port address in the band is represented to wrap, and indicate and error control code at initial/bag end, the IO level standard is LVDS, and every data wire minimum speed limit is 622Mb/s, and source bilateral minimum sampling rate along clock sampling synchronously is 311MHz; Transmission/reception fifo status passage LVTTL or LVDS IO; Data wire speed: minimum 1/4 data channel speed (LVTTL), data channel speed (bilateral), 2 fifo status data, Start-of-FIFO status signal in the band, source synchronous clock sampling along clock sampling LVDS.

Fig. 2 represents how ATM cell/elongated packet is mapped to the SPI4.2 data flow, and at this, its Payload partly is elongated, but must be the integral multiple of 16 bytes, except subsequently control word comprises effective EOP state.Its Payload control partly be exactly width be the control word (Controlwords) of 16bit, control word comprises and the more closely-related information of transfer of data, comprise port address, wrap initial/end indicator, ECC etc. (port address, start/end-of-packet indication anderror-control coding).Need to prove that the SPI4.2 bus is that to indicate current data flow by the height of the level of signal TCTL/RCTL be control word or data payload (Payload).In the process of transfer of data, control grid word is inserted in twice transmission course, in case transfer of data is triggered, Payload part will not have being transmitted of blocking-up, until the EOPS of subsequently control word the inside effectively or Payload length be the integral multiple of 16 bytes.Between the control word of the end of once transmission and transmission next time is idle control word (idle control words) and midamble code (training patterns).

Fig. 3 is a SPI4.2 bus interface signal graph, is illustrated in figure 3 as data channel and fifo status width of channel and transmit-receive position.

Fig. 4 is state of data channel figure, and as shown in Figure 4, a data transfer (data burst) must be immediately following after payload control word (Payload control words).

Fig. 5 is the fifo status channel status figure of SPI4.Therefrom as can be seen, stator channel is initially (DISABLE) state, and continuous transmit status word " 11 ", when transmission is enabled, stator channel can carry out the transition to synchronous regime, and transmit status word " 11 ", then will according to " schedule " (calendar) order send corresponding fifo status word, each calendar will be repeated CALENDAR_M time, will send the DIP2 code then, and the fifo status word can be reset to the DISABLE state again.

Fig. 6 represents the character format of control word, can see bit[11:4] be 8 bit port addresses, can represent 256 port addresss altogether.In current agreement, the payload of payload control word back is exactly this content that will send to this port, that is to say, one secondary data transmits can only send to a port, in some specific occasions, when for example sending device need send identical content to a plurality of PHY device (corresponding a plurality of ports), efficient is just very low.

Next the method for carrying out multicast in the prior art is described.

Multicast is that the one or more senders of a kind of permission (multicast source) send single packet to a plurality of recipients () network technology once, simultaneously.Multicast source sends to particular multicast group to packet, and the address that only belongs to this multicast group just can receive packet.Multicast can be saved the network bandwidth greatly, because no matter what destination addresses are arranged, only transmits single packet on any link of whole network.It has improved data-transmission efficiency.Reduce backbone network and congested possibility occurred.Main frame in the multicast group can be at same physical network, also can be from different physical networks (if the support of multicast router is arranged).Usually said multicast is exactly the IP multicast, is that a kind of one or more main frame of permission (multicast source) sends single packet to the multiple host TCP/IP network technology of (once, while).The IP cast communication must depend on IP multicast address, and it is a Class D IP address in IPv4, and scope and is divided into the local link multicast address, reserves multicast address and administration authority multicast address three classes from 224.0.0.0 to 239.255.255.255.Wherein, local link multicast address scope is at 224.0.0.0～224.0.0.255, and this is the address for Routing Protocol and the reservation of other purposes, and router is not transmitted the IP bag that belongs to this scope; The reservation multicast address is 224.0.1.0～238.255.255.255, can be used for global range (as Internet) or procotol; The administration authority multicast address is 239.0.0.0～239.255.255.255, can use for organization internal, is similar to private IP address, can not be used for Internet, can limit the multicast scope.

Along with IPTV (Web TV), VOD technology and application and development such as (program requests as required), the user is more and more higher to the requirement of the network bandwidth, and the bottleneck of the network bandwidth shows especially out all the more, so multicasting technology is widely used.Yet traditional multicast is 3 layers a multicast, needs CPU usually, and the processing of exchange chip and network processing unit will take the resource of system like this, the configuration of multicast routing protocol has also been increased complexity to network, and had the problem of multicast replication point.The multicast replication point is the destination node of user IGMP request.At the multicast replication point, whether the network equipment has the IGMP request to flow to the port duplicated multicast according to port.Multicast replication point can be saved the network bandwidth more near the user more.

The SPI4.2 bus is the agreement between data link layer and the physical layer, the realization multicast can be saved the network bandwidth fully on this level, and this bus is a high-speed interface, typical physical interface has SONET, 10GEthernet, realize the multicast of different Port can reducing the requirement of system at these high-speed interfaces, have a wide range of applications the information source bandwidth.

Thus, with traditional multicast slightly different be, to be the multicast of lower one deck realizing on the SPI4.2 bus that multicast is the multicast between physical layer and the data link layer.Because the SPI4.2 bus can be supported Port address in 256 bands, be implemented in the identical packet of transmission on one group of Port at its MAC layer, so just realized the multicast of SPI4.2, physical chip realize Port in the multicast transmission, these Port send identical content to user terminal.

Current SPI4.2 bus standard is not supported multicast, and as shown in Figure 7, data each time send and can only will initiate secondary data transmission again if send to another port at 1 port.

Summary of the invention

The objective of the invention is to overcome in the prior art successively that data send can only be at the defective of a port, and then a kind of method that realizes multicast on bus is provided.

A kind of method that realizes multicast on the SPI4.2 bus provided by the present invention is used in a data transfer payload being sent at least one port, comprises step:

Payload control word group is set before described payload, and described payload control word group comprises at least two payload control words, and each described payload control word has a port address;

Above-mentioned payload is copied on the port address corresponding port.

Wherein said port is POS or SDH interface or Ethernet interface.

Wherein said multicast is the multicast on the data link layer.

The present invention also provides a kind of method of multicasting that carries out on the SPI4.2 bus, be used for packet is sent at least one physical port, described packet comprises payload and payload control word group, wherein said payload control word group comprises at least one payload control word, and each described payload control word is represented a physical port address.

Wherein said physical port is POS or SDH interface or Ethernet interface.

Wherein said multicast is the multicast on the data link layer.

Adopt the method that on bus, realizes multicast of the present invention, can on bus, realize multicast, compare, satisfied present great demand, have a good application prospect network equipment bandwidth with original agreement based on port.

Description of drawings

Fig. 1 is a SPI4.2 bus system structure chart;

Fig. 2 is that ATM cell/elongated packet is mapped to the SPI4.2 data structure diagram;

Fig. 3 is a SPI4.2 bus interface signal graph;

Fig. 4 is state of data channel figure;

Fig. 5 is transmitter side channel status figure;

Fig. 6 is the character format of payload control word of the prior art;

Fig. 7 is the payload control word and the payload of SPI4.2 bus;

Fig. 8 is the present invention realizes multicast in the SPI4.2 bus a block diagram;

Fig. 9 is the schematic diagram of the specific embodiment of the invention.

Embodiment

Below in conjunction with accompanying drawing, describe the specific embodiment of the present invention in detail.

Fig. 8 is the present invention realizes multicast in the SPI4.2 bus a block diagram.As shown in Figure 8, the method that on the SPI4.2 bus, realizes the IP multicast provided by the present invention, make and in a data transfer, payload can be sent at least one port, it comprises the steps: to be provided with payload control word group (Payload Control Word Group) before payload, wherein payload control word group comprises at least one payload control word, and each payload control word all has a port address; Then above-mentioned payload is copied on the described port.

In the present invention, based on the packet that is sent is provided with, thereby make it on the SPI4.2 bus, to realize multicast, specifically be, payload and payload control word group are set in packet, wherein payload control word group comprises at least one payload control word, and each described payload control word is represented a physical port address.

A plurality of payload control words are formed the control word group, as shown in Figure 8, the corresponding port of each control word, the payload of back will be copied on these ports, also just realize the multicast based on port.Need to prove, if payload control word zone has only a control word, then can with current protocol-compliant.

Fig. 9 is the schematic diagram of the specific embodiment of the invention.As shown in Figure 9, the interface of data link layer (Data Link) device and physical layer (PHY) device is the SPI4.2 bus, and there are a plurality of input/output ports in the line side of PHY, and port can be the POS/SDH interface, also can be gigabit ethernet interface.With the POS/SDH interface is example, and there are 4 POS48 interfaces in the PHY line side, a port of the corresponding SPI4.2 bus of each interface.In the existing SPI4.2 bus standard, because control word has only a port address, the data of control word back can only send to some ports like this, if 4 POS48 interfaces all will send identical data, just need to send 4 times, each control word difference, but data division is identical, has so just wasted the bandwidth of system greatly.

In the present invention, adopted the control word group, replaced control word, each control word group comprises 1 or a plurality of control word.If 4 physical interfaces all will send identical content, only need to adopt the control word group that comprises 4 control words, each control word is represented an actual physical port.Like this, each data that send all can copy on 4 physical ports, have saved the bandwidth of system greatly.

Certainly; the present invention also can have other various embodiments; under the situation that does not deviate from spirit of the present invention and essence thereof; those of ordinary skill in the art work as can make various corresponding changes and distortion according to the present invention, but these corresponding changes and distortion all should belong to the protection range of the appended claim of the present invention.

Claims

1, a kind of method that realizes multicast on the SPI4.2 bus is used in a data transfer payload being sent at least two ports, comprises step:

Above-mentioned payload is copied on the port address corresponding port.

2, the method for claim 1 is characterized in that, wherein said port is POS or SDH interface or Ethernet interface.

3, method as claimed in claim 1 or 2 is characterized in that, wherein said multicast is the multicast on the data link layer.

4, a kind of method of multicasting that carries out on the SPI4.2 bus is used for packet is sent at least two physical ports, it is characterized in that:

Described packet comprises payload and payload control word group, and wherein said payload control word group comprises at least two payload control words, and each described payload control word is represented a physical port address; Payload is copied to physical port address corresponding physical port.

5, method as claimed in claim 4 is characterized in that, wherein said physical port is POS or SDH interface or Ethernet interface.

As claim 4 or 5 described methods, it is characterized in that 6, wherein said multicast is the multicast on the data link layer.