CN102780638A - Permanent virtual channel scheduling method and device - Google Patents
Permanent virtual channel scheduling method and device Download PDFInfo
- Publication number
- CN102780638A CN102780638A CN2012102904641A CN201210290464A CN102780638A CN 102780638 A CN102780638 A CN 102780638A CN 2012102904641 A CN2012102904641 A CN 2012102904641A CN 201210290464 A CN201210290464 A CN 201210290464A CN 102780638 A CN102780638 A CN 102780638A
- Authority
- CN
- China
- Prior art keywords
- pvc
- service
- vbr
- message
- scheduling
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Abstract
The invention provides a permanent virtual channel scheduling method and device. The method comprises the following steps of: in each cell sending period, according to a preset CBR (constant bit rate) service slot time scheduling table, inquiring whether a PVC (permanent virtual circuit) corresponding to slot time of the current cell sending period exists, wherein the CBR service slot time scheduling table stores scheduling slot time distributed for a CBR service in advance and corresponding PVC; if corresponding PVC exists, detecting whether the corresponding PVC caches a message; if the message is cached, determining the corresponding PVC to be the scheduling PVC of the current cell sending period, so as to send a CBR service message; and if no corresponding PVC exists, or the corresponding PVC caches no message, determining the scheduling PVC of the current cell sending period from PVCs corresponding to a VBR (variable bit rate) service and a UBR (unspecified bit rate) service according to preset scheduling rules for the VBR service and the UBR service, so as to send a VBR service message or a UBR service message.
Description
Technical field
The present invention relates to the communication scheduling technology, relate in particular to a kind of Permanent Virtual Channel dispatching method and device, belong to communication technical field.
Background technology
(Asynchronous Transfer Mode, ATM) network is to use a kind of very widely data transmission network at present to asynchronous transfer mode.A main feature of atm network is to be the base unit of transmission with fixing cell; Cell length is 53 bytes; Wherein preceding 5 bytes are the letter head; Be used to characterize the control informations such as logical address, priority level of cell whereabouts, back 48 bytes are message segment, are used for loading the information from the dissimilar business of different user.Another characteristics of atm network are asynchronous time-division multiplexs, use same transmission lines can a plurality of users jointly, and different user is the asynchronous multiplexing circuit, need not give user's fixed allocation timeslice.
Type of service commonly used comprises constant bit rate (Constant Bit Rate, CBR) professional, variable bit rate (Variable Bit Rate, VBR) professional and Unspecified Bit Rate (Unspecified Bit Rate, UBR) business in the atm network.Wherein, The CBR business is with fixed bit transmission information, it typically is to require bandwidth fixed, short time delay and time delay to change little real time business, when the user has such professional message to send; Always (Peak Cell Rate PCR) transmits with fixing Peak Cell Rate; The VBR business is with variable bit rate transmission information; Specifically be divided into professional two kinds of real-time variable bit rate (VBR-rt) business and Non-Real Time Variable Bit Rate (VBR-nrt) again; The VBR business can be used PCR, long-term average cell rate (Sustainable Cell Rate; SCR) and Maximum Burst Size (Maximum Burst Size, MBS) etc. parameter characterizes; UBR service utilizes the surplus resources of network to transmit, and bandwidth, time delay and time delay variation etc. are not required.Owing to have above-mentioned multiple business type simultaneously in the atm network; And various types of traffic have different service quality (Quality of Service, QoS) demand, therefore; How dispatching in the atm network, is the very important factor that influences the atm network performance.
The dispatching method of existing atm network; Normally in each cell transmission cycle; To whole Permanent Virtual Channels (Permanent Virtual Channel; PVC) carry out poll, select the highest PVC of priority that meets scheduling transmission condition and corresponding service, as the PVC of this scheduling.In this way, because the priority of CBR business is the highest, though can carry out priority scheduling to the CBR business; But because in each cell transmission cycle; Need all PVC are inquired about, reduced the transmission rate of atm network outbound port, make that the QoS performance of atm network is lower.
Summary of the invention
To the defective that exists in the prior art, the present invention provides a kind of Permanent Virtual Channel dispatching method and device, need not in each cell transmission cycle, whole PVC to be carried out poll in order to realization, thus the QoS performance of raising atm network.
On the one hand, the present invention provides a kind of PVC dispatching method, comprising:
In each cell transmission cycle; According to the constant bit rate CBR business time-slot dispatch list that presets; Whether inquiry exists the corresponding PVC of time slot in the cycle of sending with current cell, and storing in the said CBR service dispatching time slot table is the time slot scheduling and corresponding PVC of CBR traffic assignments in advance;
If there is the PVC of said correspondence, whether buffer memory has message then to detect the PVC of said correspondence; If buffer memory has message, then the PVC with said correspondence confirms as the scheduling PVC that current cell sends the cycle, to send the CBR service message;
If there is not the PVC of said correspondence; Perhaps the PVC of said correspondence not buffer memory message is arranged; Then according to the scheduling rule of presetting variable bit rate VBR business and Unspecified Bit Rate UBR service; From the PVC of VBR business and UBR service correspondence, confirm that current cell sends the scheduling PVC in cycle, to send VBR service message or UBR service message.
On the other hand, the present invention provides a kind of PVC dispatching device, comprising:
Timer is used for the cell transmission cycle is carried out timing;
CBR service dispatching unit; Be used in each cell transmission cycle; According to the constant bit rate CBR business time-slot dispatch list that presets; Whether inquiry exists the corresponding PVC of time slot in the cycle of sending with current cell, and storing in the said CBR service dispatching time slot table is the time slot scheduling and corresponding PVC of CBR traffic assignments in advance; If there is the PVC of said correspondence, whether buffer memory has message then to detect the PVC of said correspondence; If buffer memory has message, then the PVC with said correspondence confirms as the scheduling PVC that current cell sends the cycle, to send the CBR service message;
Professional and the UBR service scheduling unit of VBR; Be used for if there is not the PVC of said correspondence; Perhaps the PVC of said correspondence not buffer memory message is arranged, the scheduling rule of then professional according to preset variable bit rate VBR and Unspecified Bit Rate UBR service is the PVC of and UBR service correspondence professional from VBR; Confirm that current cell sends the scheduling PVC in cycle, to send VBR service message or UBR service message.
According to Permanent Virtual Channel dispatching method provided by the invention and device, through pre-configured CBR business time-slot dispatch list, for the CBR traffic assignments fixedly time slot and corresponding PVC; In each cell transmission cycle; At first judge according to CBR business time-slot dispatch list whether this time slot is to distribute to the professional time slot of CBR, and when being, judge whether buffer memory has message to corresponding PVC; If buffer memory has message, then directly this PVC is dispatched; Otherwise,, from the PVC of VBR business and UBR service correspondence, confirm that current cell sends the scheduling PVC in cycle according to the scheduling rule of preset VBR business and UBR service.Can find out; Through a PVC is handled; PVC perhaps professional to VBR and that UBR service is corresponding handles, and can accomplish scheduling, has avoided in each cell transmission cycle, whole PVC being inquired about; Thereby improved the transmission rate of atm network outbound port, improved the QoS performance of atm network.
Description of drawings
Fig. 1 is the schematic flow sheet of the PVC dispatching method of one embodiment of the invention.
Fig. 2 is the sketch map of an example of CBR business time-slot dispatch list.
Fig. 3 is a schematic flow sheet of carrying out an example of PVC scheduling based on CBR business time-slot dispatch list.
Fig. 4 is the schematic flow sheet of the example of the PVC of scheduling VBR business or UBR service correspondence.
Fig. 5 is the sketch map of an example of VBR/UBR dispatch list.
The schematic flow sheet that when Fig. 6 dispatches for carrying out VBR/UBR the VBR/UBR dispatch list is upgraded.
Fig. 7 is the structural representation of the PVC dispatching device of one embodiment of the invention.
Fig. 8 is the structural representation of the PVC dispatching device of another embodiment of the present invention.
Embodiment
The PVC dispatching method of the embodiment of the invention is carried out by the PVC dispatching device; This PVC dispatching device is for example integrated to be arranged in the router of atm network; Perhaps independently be arranged in the atm network, and be connected, PVC to be provided dispatch service to it with other network equipment that need carry out PVC scheduling.
Embodiment one
Fig. 1 is the schematic flow sheet of the PVC dispatching method of one embodiment of the invention.As shown in Figure 1, this PVC dispatching method may further comprise the steps:
Particularly, be provided with timer in the PVC dispatching device, when this timer arrived in each cell transmission cycle, export a timing signal (FP), to carry out the PVC scheduling in each cell transmission cycle by the PVC dispatching device.More particularly; For example in the atm network of STM-1 level; The speed of valid data is 149.76MBps; When the PVC dispatching device adopted the internal clocking work of 7.5ns, the internal clocking periodicity that then sends a cell was: (53byte*8)/and 377.49 internal clockings of 149.76M/7.5ns ≈, so FP of per 377 internal clockings output of timer.For compensating error, behind 754 FP of the every output of timer, though once reach 377 clocks, do not export FP, to carry out clock compensation.
Also be provided with CBR business time-slot dispatch list in the PVC dispatching device, this CBR business time-slot dispatch list is to carry out power-up initializing or passage when reshuffling at the PVC dispatching device, is configured through software.Atm network with the STM-1 level is an example, and interface bandwidth is 149.76MBps, is example to divide 2340 time slots, and the bandwidth that then each time slot is corresponding is 149.76MBps/2340=64KBps.Under this scene, in the CBR business time-slot dispatch list, have 2340 list items, respectively corresponding 2340 time slots.
Fig. 2 is the sketch map of an example of CBR business time-slot dispatch list.As shown in Figure 2,2340 list items of this CBR business time-slot dispatch list take address 0-2339 and store, and each address takies 10 bits.Wherein, the higher bit (bit) of each list item is the time slot enable bit, be to represent that this time slot was taken by the corresponding PVC of the occupied channel number of time slot that back 9bit sets at 1 o'clock, and be 0 o'clock, represent this time slot unoccupied, this moment, back 9bit be a sky.
Fig. 3 is a schematic flow sheet of carrying out an example of PVC scheduling based on CBR business time-slot dispatch list.As shown in Figure 3, may further comprise the steps:
Step 301, each timer cell cycle regularly, promptly FP triggered when arriving, and in the corresponding list item in inquiry current time slots dispatch list address, whether the time slot beginning can the position be 1, and judging promptly whether time slot begins can; If then execution in step 302, if not, then execution in step 305;
Step 302 is obtained the occupied channel number of time slot;
Step 303 judges whether buffer memory has message to the corresponding PVC of the occupied channel number of time slot; If then execution in step 304, if not, then execution in step 305;
Step 304 submits to the cell of the channel number that carries this PVC to send request, promptly dispatches this PVC; Execution in step 306 afterwards;
Step 305, the PVC that scheduling VBR business or UBR service are corresponding; Execution in step 306 afterwards;
Wherein, Do not limit in the concrete implementation present embodiment of the PVC that scheduling VBR business or UBR service are corresponding; For example, can adopt in the prior art, PVC professional to VBR and UBR service carries out poll; Select and meet scheduling transmission condition and the highest PVC of service priority, as the mode of the PVC of this scheduling.
Step 306 adds 1 with the timeslot scheduling table address.
Particularly because 2340 time slots altogether, during work, always go round and begin again from address 0 to the address 2339 wheel change.
According to the PVC dispatching method of present embodiment, through pre-configured CBR business time-slot dispatch list, for the CBR traffic assignments fixedly time slot and corresponding PVC; In each cell transmission cycle; At first judge according to CBR business time-slot dispatch list whether this time slot is to distribute to the professional time slot of CBR, and when being, judge whether buffer memory has message to corresponding PVC; If buffer memory has message, then directly this PVC is dispatched; Otherwise,, from the PVC of VBR business and UBR service correspondence, confirm that current cell sends the scheduling PVC in cycle according to the scheduling rule of preset VBR business and UBR service.Can find out; Through a PVC is handled; PVC perhaps professional to VBR and that UBR service is corresponding handles, and can accomplish scheduling, has avoided in each cell transmission cycle, whole PVC being inquired about; Thereby improved the transmission rate of atm network outbound port, improved the QoS performance of atm network.
In addition; In the PVC of the foregoing description dispatching method, since professional for CBR, be to dispatch according to the fixedly time slot that distributes in the CBR business time-slot dispatch list; Can effectively reduce the professional delay jitter of CBR, thereby promote the professional QoS performance of CBR in the atm network.
Embodiment two
On the basis of the foregoing description, in the PVC dispatching method, whether buffer memory has message specifically to comprise to detect the PVC of said correspondence:
In the channel status tabulation of inquiry maintenance, whether the channel status of the PVC of said correspondence is that buffer memory has message.
Particularly, safeguard a channel status tabulation in the PVC dispatching device, the channel status of preserving whole PVC in this channel status tabulation.For example, distribute a bit for each PVC.When the message status of PVC buffer memory changed, corresponding bit was set up, and for example, PVC becomes when message is arranged from no message, and corresponding bit is set to 1, and when PVC became no message from message is arranged, bit was set to 0 accordingly.
Therefore, when the PVC dispatching device need detect a certain PVC buffer memory has message, whether be 1 can confirm through checking the corresponding bit of this PVC, if 1, know that then buffer memory has message, if 0, know that then buffer memory does not have message.
According to the PVC dispatching method of present embodiment, realized the fast detecting of PVC channel status, improved the execution efficient of PVC scheduling.
Embodiment three
On the basis of the foregoing description, in the present embodiment, the process of dispatching the corresponding PVC of VBR business or UBR service is expanded explanation.
In the present embodiment, adopt the credit administrative mechanism,, carry out cell according to bandwidth separately and send control at interval VBR business or the corresponding PVC of UBR service.
Fig. 4 is the schematic flow sheet of the example of the PVC of scheduling VBR business or UBR service correspondence.As shown in Figure 4; In the PVC of the foregoing description dispatching method, said scheduling rule according to preset variable bit rate VBR business and Unspecified Bit Rate UBR service is from the PVC of VBR business and UBR service correspondence; Confirm that current cell sends the scheduling PVC in cycle, specifically comprises:
Wherein, the order of step 401-403 is not done qualification, and it can be carried out according to any order serial, when based on field programmable gate array (FPGA) when realizing, can also executed in parallel, and to improve treatment effeciency.
Particularly, carry out power-up initializing or passage when reshuffling at the PVC dispatching device, the current accumulation credit of each PVC that VBR business or UBR service are corresponding all is set to 0.In PVC dispatching device running, in each cell transmission cycle, corresponding each PVC of VBR business or UBR service all according to separately bandwidth, accumulates current accumulation credit.For example, if the bandwidth of a certain PVC is 64KBps, then in a cell transmission cycle, accumulate 1 current accumulation credit; If the bandwidth of a certain PVC is 128KBps, then in a cell transmission cycle, accumulate 2 current accumulation credit, in this way, make that the value of the current accumulation credit of different PVC depends on the bandwidth of PVC in same cell is sent periodicity.
When dispatching the PVC of VBR business or UBR service correspondence; Respectively from the PVC that VBR-rt is professional, VBR-nrt is professional and UBR service is corresponding; Select respectively and satisfy the PVC of current accumulation credit more than or equal to time slot sum (for example being 2340); Candidate as the corresponding service type dispatches PVC, and each candidate is dispatched the corresponding current accumulation credit deduction time slot sum of PVC.
Alternatively, the PVC dispatching device is elected to many two candidates respectively and dispatches PVC for VBR-rt is professional, VBR-nrt is professional and UBR service.This at the most two candidates dispatch PVC and comprise one that selects the passage before the scheduling PVC of last time, and of selecting the passage after the scheduling PVC of last time.For example; Channel number corresponding to the professional PVC of VBR-rt is 0-64; If during the corresponding PVC of last scheduling VBR business or UBR service, scheduling be that channel number is 5 PVC, when then this time selecting the professional corresponding candidate of VBR-rt to dispatch PVC; From channel number 0-4, select one to satisfy current accumulation credit, dispatch PVC as the candidate more than or equal to 2340 PVC; And from channel number 6-64, select one to satisfy current accumulation credit more than or equal to 2340 PVC, dispatch PVC as the candidate.
Because each cell sends the cycle; Only can dispatch a PVC; The PVC dispatching device is dispatched PVC to above-mentioned a plurality of candidates and is arbitrated, according to service priority principle from high to low, and the principle of the fair wheel commentaries on classics of the different PVC of same type of service; Dispatch the PVC from the candidate, select current cell to send the scheduling PVC in cycle.Candidate for not being selected as scheduling PVC dispatches PVC, owing in the current cell transmission cycle, do not send cell, the current accumulation credit that this part PVC is corresponding adds 2340.
PVC dispatching method according to present embodiment; Through adopting the credit administrative mechanism; To VBR business or the corresponding PVC of UBR service; Carry out cell according to bandwidth separately and send control at interval, guaranteed that VBR business and UBR service have less delay jitter, effectively ensured the Qos of VBR business and UBR service.
Further; In the PVC of the foregoing description dispatching method, said according to service priority principle from high to low, and the principle of the fair wheel commentaries on classics of the different PVC of same type of service; Dispatch the PVC from said candidate; Select said current cell to send the scheduling PVC in cycle, specifically comprise schedule level one and second-level dispatching, wherein:
Said schedule level one comprises: if exist a plurality of candidates of same type of service to dispatch PVC, then according to the scheduling PVC of last corresponding service type, according to the principle that the justice wheel changes, the candidate who selects a corresponding service type dispatches PVC;
Said second-level dispatching comprises: dispatch the PVC from the candidate of the different service types of said schedule level one output; Selection has, and the candidate of high service priority dispatches PVC; Send the scheduling PVC in cycle as said current cell; Wherein, the professional service priority of said VBR-rt is higher than the professional service priority of said VBR-nrt, and the professional service priority of said VBR-nrt is higher than the service priority of said UBR service.
Particularly; For example dispatch PVC and comprise that channel number is that two PVC of 3 and 7 are example corresponding to the professional candidate of VBR-rt; Because the channel number of last scheduling PVC is 5; Dispatch PVC so schedule level one according to the principle that justice wheel changes (RR), is selected channel number and be 7 PVC as the professional candidate of VBR-rt, export second-level dispatching to.In this way, the professional candidate with the UBR service correspondence of VBR-nrt is dispatched PVC and carry out similar processing.
Candidate at the most corresponding to each type of service that second-level dispatching receives schedule level one to be provided dispatches PVC, and screens according to service priority, will have the candidate of high service priority and dispatch PVC and confirm as the scheduling PVC that current cell sends the cycle.
Embodiment four
On the basis of the foregoing description, in each cell transmission cycle, professional each the corresponding PVC of the professional and said VBR-nrt of said VBR-rt is if buffer memory message is not then accumulated the burst length credit according to SCR; If buffer memory has message, and satisfy said burst length credit, then will give prominence to the length credit and convert current accumulation credit into according to PCR more than or equal to said time slot sum; If buffer memory has message, and said burst length credit is then accumulated current accumulation credit according to SCR less than said time slot sum; Among each PVC of said UBR service correspondence, accumulate current accumulation credit according to PCR.
Particularly, safeguard a VBR/UBR dispatch list in the PVC dispatching device, comprise channel parameters and the intermediate variable of each PVC that VBR-rt is professional, VBR-nrt is professional and UBR service is corresponding in this table.Fig. 5 is the sketch map of an example of VBR/UBR dispatch list.As shown in Figure 5, be scheduling to example with the VBR/UBR of 256 PVC of PVC dispatching device support, use 256 addresses (address 0-255) to store channel parameters and the intermediate variable of 256 PVC respectively.
Corresponding channel parameters and the intermediate variable in each address takies 99bit altogether.Corresponding explanation is following:
The SCR of [11:0]: PVC sets, and the smallest particles degree is 64K; For example, represent 64KBps with 000000000001, represent 128KBps etc. with 000000000010;
The PCR of [23:12]: PVC sets, and the smallest particles degree is 64K; For example, represent 64KBps with 000000000001, represent 128KBps etc. with 000000000010;
[52:24]: MBS sets, and is converted into credit: MBS * 2340; Such as burst length is 10, and then set point is 23400;
The type of service of [54:53]: PVC: " 00 " expression keeps, " 01 " expression VBR_rt, " 10 " expression VBR_nrt, " 11 " expression UBR;
[55]: the accumulation mode of current accumulation credit, " 1 " expression is accumulated according to the SCR of PVC, and " 0 " expression is accumulated according to the PCR of PVC; For type of service is the PVC of UBR, and this bit is set to " 0 ", is the PVC of VBR_rt or VBR_nrt for type of service, and this bit can dynamic change in running;
The current accumulation credit of [68:56]: PVC is expressed as CUR_TOKEN;
The burst length credit of [97:69]: PVC is expressed as BURST_TOKEN_LEFT;
[98]: the passage enabler flags.
When the channel service type configuration was carried out in system initialization configuration or centre, software was filled in the parameter of bit54 to bit0, and bit98 is set, and enables passage.Other are 0, the intermediate variable when being used for as PVC dispatching device operation dispatching.In each cell transmission cycle, each PVC in the VBR/UBR dispatch list carries out the credit accumulation, and corresponding intermediate variable is upgraded, and is elaborated in the face of this renewal process down.
The PVC dispatching device adopts the twin-tub design for VBR is professional, promptly adopts bucket corresponding to the burst length credit (below be called the BURST_TOKEN_LEFT bucket) simultaneously, and corresponding to the bucket of current accumulation credit (below be called the CUR_TOKEN bucket).In each cell transmission cycle, as PVC not during the buffer memory message, the burst length credit in the BURST_TOKEN_LEFT bucket is accumulated, when the PVC buffer memory has message, the current accumulation credit in the CUR_TOKEN bucket is accumulated.
Wherein, As PVC not during the buffer memory message; The PVC dispatching device is accumulated the burst length credit according to the SCR of PVC, and for example if SCR is 64KBps, then a cell transmission cycle is accumulated 1 burst length credit; If SCR is 128KBps, then a cell transmission cycle is accumulated 2 burst length credit; Burst length credit in the BURST_TOKEN_LEFT bucket is accumulated to MBS * 2340 at most, reach this value after, do not proceed to accumulate.
When the PVC buffer memory had message, less than 2340, then the current accumulation credit in the CUR_TOKEN bucket was accumulated according to the SCR of PVC as if the burst length credit in the BURST_TOKEN_LEFT bucket; If the burst length credit in the BURST_TOKEN_LEFT bucket is more than or equal to 2340; Then the burst length credit in the BURST_TOKEN_LEFT bucket is moved to the CUR_TOKEN bucket according to the PCR of PVC, makes current accumulation credit accumulate according to the PCR of PVC; For example if PCR is 256KBps, then a cell sends the cycle, reduces by 4 burst length credit in the BURST_TOKEN_LEFT bucket, and increases by 4 current accumulation credit in the CUR_TOKEN bucket.Current accumulation credit in the CUR_TOKEN bucket is accumulated to 4680 at most, reach this value after, do not proceed to accumulate.
The PVC dispatching device only adopts the CUR_TOKEN bucket for UBR service, and promptly in each cell transmission cycle, the PCR according to PVC accumulates to the current accumulation credit in the CUR_TOKEN bucket.
The schematic flow sheet that when Fig. 6 dispatches for carrying out VBR/UBR the VBR/UBR dispatch list is upgraded.Among Fig. 6, be treated to example, describe with list item to a PVC in the VBR/UBR dispatch list.As shown in Figure 6, may further comprise the steps:
Step 603 is dispatched PVC with this PVC as the candidate, and credit is reduced; Afterwards, execution in step 605;
Particularly, the cell that sends the channel number that carries this PVC sends request, and the candidate is selected in prompting dispatches PVC, and the current accumulation credit in the CUR_TOKEN bucket is deducted 2340; If the type of service of this PVC is VBR (comprising VBR_rt and VBR_nrt), then if the burst length credit in the BURST_TOKEN_LEFT bucket more than or equal to 2340, also deducts 2340 with the burst length credit.
Step 604 is written back to credit in the VBR/UBR dispatch list, and process ends;
Step 605 is written back to credit in the VBR/UBR dispatch list, and execution in step 606;
Step 606 judges that this candidate dispatches PVC and whether finally is confirmed as scheduling PVC, if, process ends then; If not, execution in step 607 then;
Step 607 is returned the credit of reducing in the step 603 and is added to the VBR/UBR dispatch list.
PVC dispatching method according to present embodiment; Through the professional employing of VBR twin-tub is designed; Promptly adopt BURST_TOKEN_LEFT bucket and CUR_TOKEN bucket simultaneously, make that the long-term average cell rate that can either guarantee PVC is SCR for the VBR business; Can happen suddenly according to PCR at short notice again, further improve the professional Qos of VBR.
Embodiment five
Fig. 7 is the structural representation of the PVC dispatching device of one embodiment of the invention.As shown in Figure 7, this PVC dispatching device comprises:
Timer 71 is used for the cell transmission cycle is carried out timing;
CBR service dispatching unit 72; Be used in each cell transmission cycle; According to the constant bit rate CBR business time-slot dispatch list that presets; Whether inquiry exists the corresponding PVC of time slot in the cycle of sending with current cell, and storing in the said CBR service dispatching time slot table is the time slot scheduling and corresponding PVC of CBR traffic assignments in advance; If there is the PVC of said correspondence, whether buffer memory has message then to detect the PVC of said correspondence; If buffer memory has message, then the PVC with said correspondence confirms as the scheduling PVC that current cell sends the cycle, to send the CBR service message;
Professional and the UBR service scheduling unit 73 of VBR; Be used for if there is not the PVC of said correspondence; Perhaps the PVC of said correspondence not buffer memory message is arranged, the scheduling rule of then professional according to preset variable bit rate VBR and Unspecified Bit Rate UBR service is the PVC of and UBR service correspondence professional from VBR; Confirm that current cell sends the scheduling PVC in cycle, to send VBR service message or UBR service message.
Particularly, the flow process that the PVC dispatching device of present embodiment is carried out the PVC scheduling is identical with the PVC dispatching method of the foregoing description, so locate to repeat no more.
According to the PVC dispatching device of present embodiment, through pre-configured CBR business time-slot dispatch list, for the CBR traffic assignments fixedly time slot and corresponding PVC; In each cell transmission cycle; At first judge according to CBR business time-slot dispatch list whether this time slot is to distribute to the professional time slot of CBR, and when being, judge whether buffer memory has message to corresponding PVC; If buffer memory has message, then directly this PVC is dispatched; Otherwise,, from the PVC of VBR business and UBR service correspondence, confirm that current cell sends the scheduling PVC in cycle according to the scheduling rule of preset VBR business and UBR service.Can find out; Through a PVC is handled; PVC perhaps professional to VBR and that UBR service is corresponding handles, and can accomplish scheduling, has avoided in each cell transmission cycle, whole PVC being inquired about; Thereby improved the transmission rate of atm network outbound port, improved the QoS performance of atm network.
In addition; In the PVC of the foregoing description dispatching device, since professional for CBR, be to dispatch according to the fixedly time slot that distributes in the CBR business time-slot dispatch list; Can effectively reduce the professional delay jitter of CBR, thereby promote the professional QoS performance of CBR in the atm network.
Embodiment six
Fig. 8 is the structural representation of the PVC dispatching device of another embodiment of the present invention.As shown in Figure 8, this PVC dispatching device also comprises:
Channel status memory cell 74 is used for the maintenance channel status list;
Correspondingly, said CBR service dispatching unit 72 specifically is used for the channel status tabulation of inquiry maintenance, and whether the channel status of the PVC of said correspondence is that buffer memory has message.
Wherein, channel status memory cell 74 for example realizes through any memory.
Further, in the PVC dispatching device, said VBR business and UBR service scheduling unit 73 specifically are used for:
From professional each the corresponding PVC of real-time variable bit rate VBR-rt; Choosing at the most two current accumulation credit has the PVC of message more than or equal to time slot sum and buffer memory; Candidate as being used to send the VBR-rt service message dispatches PVC, and the current accumulation credit that said candidate dispatches PVC is deducted said time slot sum;
From professional each the corresponding PVC of Non-Real Time Variable Bit Rate VBR-nrt; Choosing at the most two current accumulation credit has the PVC of message more than or equal to time slot sum and buffer memory; Candidate as being used to send the VBR-nrt service message dispatches PVC, and the current accumulation credit that said candidate dispatches PVC is deducted said time slot sum;
From each corresponding PVC of UBR service; Choosing at the most two current accumulation credit has the PVC of message more than or equal to time slot sum and buffer memory; Candidate as being used to send the UBR service message dispatches PVC, and the current accumulation credit that said candidate dispatches PVC is deducted said time slot sum;
Correspondingly; The PVC dispatching device also comprises scheduling result arbitration unit 75, is used for: according to service priority principle from high to low, and the principle of the fair wheel commentaries on classics of the different PVC of same type of service; Dispatch the PVC from said candidate, select said current cell to send the scheduling PVC in cycle;
Correspondingly, said VBR is professional also is used for UBR service scheduling unit 73: the current accumulation credit that the candidate who will not be selected as said scheduling PVC dispatches PVC returns that to add said time slot total; Wherein, the current accumulation credit of each PVC is to confirm according to the bandwidth of each PVC and the periodicity that do not send cell.
Further, said VBR is professional specifically to be used for UBR service scheduling unit 73: in each cell transmission cycle, if buffer memory message is not then accumulated the burst length credit according to SCR; If buffer memory has message, and satisfy said burst length credit, then will give prominence to the length credit and convert current accumulation credit into according to PCR more than or equal to said time slot sum; If buffer memory has message, and said burst length credit is then accumulated current accumulation credit according to SCR less than said time slot sum; Among each PVC of said UBR service correspondence, accumulate current accumulation credit according to PCR.
Further, said scheduling result arbitration unit 75 comprises schedule level one subelement and second-level dispatching subelement (not shown), wherein:
Said schedule level one subelement is used for if exist two candidates of same type of service to dispatch PVC, and then according to the scheduling PVC of last corresponding service type, according to the principle that the justice wheel changes, the candidate who selects a corresponding service type dispatches PVC;
Said second-level dispatching subelement; Be used for dispatching PVC from the candidate of the different service types of said schedule level one subelement output; Selection has that the candidate of high service priority dispatches PVC, sends the scheduling PVC in cycle as said current cell, wherein; The professional service priority of said VBR-rt is higher than the professional service priority of said VBR-nrt, and the professional service priority of said VBR-nrt is higher than the service priority of said UBR service.
In addition; The PVC dispatching device also can comprise a dispatching command generation unit 76 that is connected with scheduling result arbitration unit 75 with CBR service dispatching unit 72; Be used for the scheduling PVC that provides according to CBR service dispatching unit 72 or scheduling result arbitration unit 75; Generate dispatching command, be sent to corresponding network device, do not limit in the concrete form embodiment of the invention.
Preferably, integrated field programmable gate array (FPGA) chip internal that is arranged on of the PVC dispatching device of above-mentioned arbitrary embodiment.And VBR quantity professional and the UBR service scheduling unit can not limit in the embodiment of the invention for one or more.
What should explain at last is: above embodiment is only in order to explaining technical scheme of the present invention, but not to its restriction; Although with reference to previous embodiment the present invention has been carried out detailed explanation, those of ordinary skill in the art is to be understood that: it still can be made amendment to the technical scheme that aforementioned each embodiment put down in writing, and perhaps part technical characterictic wherein is equal to replacement; And these are revised or replacement, do not make the spirit and the scope of the essence disengaging various embodiments of the present invention technical scheme of relevant art scheme.
Claims (11)
1. a Permanent Virtual Channel PVC dispatching method is characterized in that, comprising:
In each cell transmission cycle; According to the constant bit rate CBR business time-slot dispatch list that presets; Whether inquiry exists the corresponding PVC of time slot in the cycle of sending with current cell, and storing in the said CBR service dispatching time slot table is the time slot scheduling and corresponding PVC of CBR traffic assignments in advance;
If there is the PVC of said correspondence, whether buffer memory has message then to detect the PVC of said correspondence; If buffer memory has message, then the PVC with said correspondence confirms as the scheduling PVC that current cell sends the cycle, to send the CBR service message;
If there is not the PVC of said correspondence; Perhaps the PVC of said correspondence not buffer memory message is arranged; Then according to the scheduling rule of presetting variable bit rate VBR business and Unspecified Bit Rate UBR service; From the PVC of VBR business and UBR service correspondence, confirm that current cell sends the scheduling PVC in cycle, to send VBR service message or UBR service message.
2. PVC dispatching method according to claim 1 is characterized in that, whether buffer memory has message specifically to comprise to the PVC of the said correspondence of said detection:
In the channel status tabulation of inquiry maintenance, whether the channel status of the PVC of said correspondence is that buffer memory has message.
3. PVC dispatching method according to claim 1 is characterized in that, said scheduling rule according to preset VBR business and UBR service from the PVC of VBR business and UBR service correspondence, confirms that current cell sends the scheduling PVC in cycle, specifically comprises:
From professional each the corresponding PVC of real-time variable bit rate VBR-rt; Choosing current accumulation credit has the PVC of message more than or equal to time slot sum and buffer memory; Candidate as being used to send the VBR-rt service message dispatches PVC, and the current accumulation credit that said candidate dispatches PVC is deducted said time slot sum;
From professional each the corresponding PVC of Non-Real Time Variable Bit Rate VBR-nrt; Choosing current accumulation credit has the PVC of message more than or equal to time slot sum and buffer memory; Candidate as being used to send the VBR-nrt service message dispatches PVC, and the current accumulation credit that said candidate dispatches PVC is deducted said time slot sum;
From each corresponding PVC of UBR service; Choosing current accumulation credit has the PVC of message more than or equal to time slot sum and buffer memory; Candidate as being used to send the UBR service message dispatches PVC, and the current accumulation credit that said candidate dispatches PVC is deducted said time slot sum;
According to service priority principle from high to low, and the principle of the fair wheel commentaries on classics of the different PVC of same type of service, dispatch the PVC from said candidate, select said current cell to send the scheduling PVC in cycle;
The current accumulation credit that the candidate who is not selected as said scheduling PVC is dispatched PVC is returned and is added said time slot sum;
Wherein, the current accumulation credit of each PVC is to confirm according to the bandwidth of each PVC and the periodicity that do not send cell.
4. PVC dispatching method according to claim 3; It is characterized in that, in each cell transmission cycle, professional each the corresponding PVC of the professional and said VBR-nrt of said VBR-rt; If the buffer memory message is not then accumulated the burst length credit according to long-term average cell rate SCR; If buffer memory has message, and satisfy said burst length credit, then will give prominence to the length credit and convert current accumulation credit into according to Peak Cell Rate PCR more than or equal to said time slot sum; If buffer memory has message, and said burst length credit is then accumulated current accumulation credit according to SCR less than said time slot sum; Among each PVC of said UBR service correspondence, accumulate current accumulation credit according to PCR.
5. PVC dispatching method according to claim 3; It is characterized in that, said according to service priority principle from high to low, and the principle of the fair wheel commentaries on classics of the different PVC of same type of service; Dispatch the PVC from said candidate; Select said current cell to send the scheduling PVC in cycle, specifically comprise schedule level one and second-level dispatching, wherein:
Said schedule level one comprises: if exist a plurality of candidates of same type of service to dispatch PVC, then according to the scheduling PVC of last corresponding service type, according to the principle that the justice wheel changes, the candidate who selects a corresponding service type dispatches PVC;
Said second-level dispatching comprises: dispatch the PVC from the candidate of the different service types of said schedule level one output; Selection has, and the candidate of high service priority dispatches PVC; Send the scheduling PVC in cycle as said current cell; Wherein, the professional service priority of said VBR-rt is higher than the professional service priority of said VBR-nrt, and the professional service priority of said VBR-nrt is higher than the service priority of said UBR service.
6. a PVC dispatching device is characterized in that, comprising:
Timer is used for the cell transmission cycle is carried out timing;
CBR service dispatching unit; Be used in each cell transmission cycle; According to the constant bit rate CBR business time-slot dispatch list that presets; Whether inquiry exists the corresponding PVC of time slot in the cycle of sending with current cell, and storing in the said CBR service dispatching time slot table is the time slot scheduling and corresponding PVC of CBR traffic assignments in advance; If there is the PVC of said correspondence, whether buffer memory has message then to detect the PVC of said correspondence; If buffer memory has message, then the PVC with said correspondence confirms as the scheduling PVC that current cell sends the cycle, to send the CBR service message;
Professional and the UBR service scheduling unit of VBR; Be used for if there is not the PVC of said correspondence; Perhaps the PVC of said correspondence not buffer memory message is arranged, the scheduling rule of then professional according to preset variable bit rate VBR and Unspecified Bit Rate UBR service is the PVC of and UBR service correspondence professional from VBR; Confirm that current cell sends the scheduling PVC in cycle, to send VBR service message or UBR service message.
7. PVC dispatching device according to claim 6 is characterized in that, also comprises:
The channel status memory cell is used for the maintenance channel status list;
Correspondingly, said CBR service dispatching unit specifically is used for the channel status tabulation of inquiry maintenance, and whether the channel status of the PVC of said correspondence is that buffer memory has message.
8. PVC dispatching device according to claim 6 is characterized in that, said VBR business and UBR service scheduling unit specifically are used for:
From professional each the corresponding PVC of real-time variable bit rate VBR-rt; Choosing at the most two current accumulation credit has the PVC of message more than or equal to time slot sum and buffer memory; Candidate as being used to send the VBR-rt service message dispatches PVC, and the current accumulation credit that said candidate dispatches PVC is deducted said time slot sum;
From professional each the corresponding PVC of Non-Real Time Variable Bit Rate VBR-nrt; Choosing at the most two current accumulation credit has the PVC of message more than or equal to time slot sum and buffer memory; Candidate as being used to send the VBR-nrt service message dispatches PVC, and the current accumulation credit that said candidate dispatches PVC is deducted said time slot sum;
From each corresponding PVC of UBR service; Choosing at the most two current accumulation credit has the PVC of message more than or equal to time slot sum and buffer memory; Candidate as being used to send the UBR service message dispatches PVC, and the current accumulation credit that said candidate dispatches PVC is deducted said time slot sum;
Correspondingly; The PVC dispatching device also comprises the scheduling result arbitration unit, is used for: according to service priority principle from high to low, and the principle of the fair wheel commentaries on classics of the different PVC of same type of service; Dispatch the PVC from said candidate, select said current cell to send the scheduling PVC in cycle;
Correspondingly, said VBR is professional also is used for the UBR service scheduling unit: the current accumulation credit that the candidate who will not be selected as said scheduling PVC dispatches PVC returns that to add said time slot total; Wherein, the current accumulation credit of each PVC is to confirm according to the bandwidth of each PVC and the periodicity that do not send cell.
9. PVC dispatching device according to claim 8; It is characterized in that; Said VBR business and UBR service scheduling unit specifically are used for: in each cell transmission cycle; Professional each the corresponding PVC of the professional and said VBR-nrt of said VBR-rt is if buffer memory message is not then accumulated the burst length credit according to SCR; If buffer memory has message, and satisfy said burst length credit, then will give prominence to the length credit and convert current accumulation credit into according to PCR more than or equal to said time slot sum; If buffer memory has message, and said burst length credit is then accumulated current accumulation credit according to SCR less than said time slot sum; Among each PVC of said UBR service correspondence, accumulate current accumulation credit according to PCR.
10. PVC dispatching device according to claim 8 is characterized in that, said scheduling result arbitration unit comprises schedule level one subelement and second-level dispatching subelement, wherein:
Said schedule level one subelement is used for if exist two candidates of same type of service to dispatch PVC, and then according to the scheduling PVC of last corresponding service type, according to the principle that the justice wheel changes, the candidate who selects a corresponding service type dispatches PVC;
Said second-level dispatching subelement; Be used for dispatching PVC from the candidate of the different service types of said schedule level one subelement output; Selection has that the candidate of high service priority dispatches PVC, sends the scheduling PVC in cycle as said current cell, wherein; The professional service priority of said VBR-rt is higher than the professional service priority of said VBR-nrt, and the professional service priority of said VBR-nrt is higher than the service priority of said UBR service.
11., it is characterized in that said timer and each unit are implemented in the on-site programmable gate array FPGA chip internal according to the arbitrary described PVC dispatching device of claim 6-10.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201210290464.1A CN102780638B (en) | 2012-08-15 | 2012-08-15 | Permanent virtual channel scheduling method and device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201210290464.1A CN102780638B (en) | 2012-08-15 | 2012-08-15 | Permanent virtual channel scheduling method and device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN102780638A true CN102780638A (en) | 2012-11-14 |
| CN102780638B CN102780638B (en) | 2015-07-22 |
Family
ID=47125399
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201210290464.1A Active CN102780638B (en) | 2012-08-15 | 2012-08-15 | Permanent virtual channel scheduling method and device |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN102780638B (en) |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5345445A (en) * | 1992-11-06 | 1994-09-06 | At&T Bell Laboratories | Establishing telecommunications calls in a broadband network |
| JP2002044087A (en) * | 2000-07-21 | 2002-02-08 | Hitachi Telecom Technol Ltd | Atm communication equipment |
| CN1750517A (en) * | 2005-11-07 | 2006-03-22 | 中兴通讯股份有限公司 | Method for realizing service wide band warranty |
| CN1852285A (en) * | 2005-12-30 | 2006-10-25 | 华为技术有限公司 | Permanent virtual channel scheduling method for carrying variable bit ratio business |
| CN101051988A (en) * | 2007-05-22 | 2007-10-10 | 杭州华三通信技术有限公司 | Method and device for dispatching permanent virtual path |
| CN101064697A (en) * | 2006-04-28 | 2007-10-31 | 中兴通讯股份有限公司 | Apparatus and method for realizing asynchronous transmission mode network service quality control |
| CN101459932A (en) * | 2009-01-06 | 2009-06-17 | 北京交通大学 | Wireless Mesh network MAC layer bandwidth request and allocation method based on IEEE802.16d standard |
-
2012
- 2012-08-15 CN CN201210290464.1A patent/CN102780638B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5345445A (en) * | 1992-11-06 | 1994-09-06 | At&T Bell Laboratories | Establishing telecommunications calls in a broadband network |
| JP2002044087A (en) * | 2000-07-21 | 2002-02-08 | Hitachi Telecom Technol Ltd | Atm communication equipment |
| CN1750517A (en) * | 2005-11-07 | 2006-03-22 | 中兴通讯股份有限公司 | Method for realizing service wide band warranty |
| CN1852285A (en) * | 2005-12-30 | 2006-10-25 | 华为技术有限公司 | Permanent virtual channel scheduling method for carrying variable bit ratio business |
| CN101064697A (en) * | 2006-04-28 | 2007-10-31 | 中兴通讯股份有限公司 | Apparatus and method for realizing asynchronous transmission mode network service quality control |
| CN101051988A (en) * | 2007-05-22 | 2007-10-10 | 杭州华三通信技术有限公司 | Method and device for dispatching permanent virtual path |
| CN101459932A (en) * | 2009-01-06 | 2009-06-17 | 北京交通大学 | Wireless Mesh network MAC layer bandwidth request and allocation method based on IEEE802.16d standard |
Also Published As
| Publication number | Publication date |
|---|---|
| CN102780638B (en) | 2015-07-22 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US5946297A (en) | Scheduling method and apparatus for supporting ATM connections having a guaranteed minimun bandwidth | |
| US6646986B1 (en) | Scheduling of variable sized packet data under transfer rate control | |
| US6167030A (en) | Buffer-based traffic measurement system and method for nominal bit rate (NBR) service | |
| US7313407B2 (en) | Allocation of radio resources in a CDMA2000 cellular system | |
| US8031598B2 (en) | Flow-rate-regulated burst switches | |
| US5970062A (en) | Method and apparatus for providing wireless access to an ATM network | |
| US7369491B1 (en) | Regulating data-burst transfer | |
| US6633585B1 (en) | Enhanced flow control in ATM edge switches | |
| CN1921444B (en) | Method for classified package dispatching and resource distributing based on service quality, and communication device | |
| CN108282415A (en) | A kind of dispatching method and equipment | |
| US5818839A (en) | Timing reference for scheduling data traffic on multiple ports | |
| CA2229577A1 (en) | Method and apparatus for controlling traffic flows in a packet-switched network in order to guarantee service performance | |
| CN101459965B (en) | Method, device and communication system for resource scheduling | |
| CN108462649A (en) | The method and apparatus for reducing high-priority data propagation delay time under congestion state in ONU | |
| CN100466593C (en) | Method of implementing integrated queue scheduling for supporting multi service | |
| Kesidis et al. | Extremal shape-controlled traffic patterns in high-speed networks | |
| Moorman et al. | Multiclass priority fair queuing for hybrid wired/wireless quality of service support | |
| CN102780638B (en) | Permanent virtual channel scheduling method and device | |
| CN100479412C (en) | Method and device for dispatching permanent virtual path | |
| US6088331A (en) | Parallel service-rate controllers in ATM switches | |
| Bucheli et al. | Compensation modeling for QoS support on a wireless network | |
| RU2335085C1 (en) | Method for organisation and control of data burst transmission and device for its implementation | |
| Khawam et al. | Opportunistic weighted fair queueing | |
| Inoue et al. | ABR message transfer schemes in wireless ATM networks | |
| JP3177188B2 (en) | Packet transmitting / receiving method and apparatus |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CP01 | Change in the name or title of a patent holder | ||
| CP01 | Change in the name or title of a patent holder |
Address after: Cangshan District of Fuzhou City, Fujian province 350002 Jinshan Road No. 618 Garden State Industrial Park 19 floor Patentee after: RUIJIE NETWORKS Co.,Ltd. Address before: Cangshan District of Fuzhou City, Fujian province 350002 Jinshan Road No. 618 Garden State Industrial Park 19 floor Patentee before: Beijing Star-Net Ruijie Networks Co.,Ltd. |