CN100558100C - The method of channel SQ rearrangement in the source virtual capacity group in LCAS - Google Patents

Abstract

The invention discloses a method for channel SQ rearrangement in a virtual capacity group at a source end in LCAS. If other channels in the VCG appear in the query, query the configuration table to obtain the SQ number of the channel. If it is a valid value, compare it with the SQ_DEL recorded in the VCG. If it is less than SQ_DEL, keep the SQ numbers of other channels unchanged. change; if it is greater than VCG SQ_DEL, the SQ number of other channels will be decremented by 1 as its SQ number; after all the channels in the VCG are processed relative to the currently recorded SQ_DEL, the maximum value of the SQ recorded in this VCG will be decremented by 1 , as the maximum value of SQ used for the newly recorded VCG. The present invention uses less logic resources to complete the rearrangement of SQ by hardware, thereby reducing the work of software.

Description

The method of channel SQ rearrangement in the source virtual capacity group in LCAS

Technical field:

The invention relates to a method for rearranging channels of a virtual capacity group in an LCAS, in particular to a method for rearranging channels SQ in a virtual capacity group at a source end in an LCAS.

Background technique:

When a Synchronous Digital Hierarchy (SDH, Synchronous Digital Hierarchy) system carries services, in order to carry services with large bandwidth requirements, multiple VCs (Virtual Capacity, virtual containers) are usually bundled together for use. The multi-VC bundling realized by the virtual concatenation technology only has requirements for equipment at the upper and lower sites of the virtual concatenation service, and has no special requirements for the rest of the sites, so it has been greatly developed. The LCAS (LinkCapacity Adjustment Scheme) protocol is an enhancement of virtual concatenation. In SDH transmission services, the main function of LCAS is to use the reserved bytes of SDH overhead to define the control frame structure and control the carried The number of VCs required for data service bandwidth mapping, and supports dynamic and lossless bandwidth (that is, the number of members in the virtual capacity group) adjustment. Here, the LCAS technology is briefly introduced. LCAS was originally called VBA (Variable Bandwidth Allocation, variable bandwidth allocation) technology. It can be seen that LCAS technology has the characteristics of flexible bandwidth and dynamic adjustment. When the user bandwidth changes, the number of Members in the VCG (Virtual Concatenation Group, virtual capacity group) can be adjusted. This adjustment will not affect the user normal business interruption. In addition, LCAS technology also provides a fault-tolerant mechanism: when a member in the virtual capacity group fails, the entire virtual capacity group will not be invalidated, but the failed member will be automatically removed from the virtual capacity group, and the remaining normal members will Continue to transmit services; when the failed member recovers, the system will automatically add the failed member to the virtual capacity group. Generally speaking, there are two reasons for LCAS technology to adjust VCG, namely, link status changes: when LCAS detects that a Member fails on the network, it will temporarily block the same channel and automatically reduce the capacity of VCG; After the invalid member is repaired, re-enable the channel and automatically increase the capacity of the VCG. This capacity adjustment is feasible for each Member. Changes in bandwidth configuration: The control mechanism between the source and destination of LCAS can adjust the capacity of VCG according to the actual service bandwidth requirements, and specifically adjust the used VCG capacity according to the service flow and bandwidth. In addition, the VCG also has an identification field GID (Group Identification bit, group identification), which is used to identify the VCG, and all members of the same VCG have the same GID. Different members in the same VCG have different channel SQ (Sequence Indicator) sequence numbers, and different frames of the same member have different MFI (Multi Frame Indicator).

The regeneration of services by virtual concatenation is completed according to the sequence number SQ of the channel and the multiframe number MFI. Therefore, the allocation of the channel number SQ by the source is very important. There are two traditional methods for processing the LCAS source serial number, one is completely processed by software, this method will consume more CPU resources when multiple virtual concatenation groups (VCGs) coexist, and at the same time There is also the synchronization problem of software and hardware. Another method is to centrally process the members of the same VCG by hardware, and complete the rearrangement of the SQs of all members of the VCG at one time, which will undoubtedly consume a lot of logic resources.

Invention content:

Aiming at the existing problems and deficiencies in the channel rearrangement at the source end of the LCAS, the purpose of the present invention is to provide a method for more conveniently and quickly completing the SQ rearrangement of channels in the virtual capacity group at the source end in the LCAS.

The present invention is realized in the following way: a method for rearranging channel SQ in a source-end virtual capacity group in LCAS, wherein the method for rearranging channel SQ in a source-end virtual capacity group in LCAS is through a comparison circuit and a multiplexer Realize, described method comprises the following steps:

b. Start to query each VC channel in the current VCG; after the LCAS source has inquired about a channel that needs to be deleted in the VCG, it will no longer search for other channels that need to be deleted, record the current SQ of this channel as SQ_DEL, and simultaneously SQ is updated to an invalid value and proceeds to step c;

c. When rearranging, when other passages in the VCG appear, query the configuration table to obtain the SQ of the other passages, if the SQ of the other passages is a valid value, compare it with the recorded SQ_DEL of the VCG, If it is less than the SQ_DEL recorded by the VCG, then keep the SQ of the other channels unchanged; if it is greater than the SQ_DEL recorded by the VCG, then subtract 1 from the SQ of the other channels as its new SQ; all in the VCG After the processing of the channel relative to the currently recorded SQ_DEL is completed, subtract 1 from the maximum value of the SQ recorded in the VCG and use it as the maximum value of the SQ used by the newly recorded VCG.

Further, the method also includes:

d. Continue to query other channels that need to be deleted in the VCG. If there is a channel that needs to be deleted in the VCG, then jump to the LCAS source in step b after querying the channel that needs to be deleted in the VCG. A step of.

Further, if it is found that there is no channel that needs to be deleted in the VCG, the method also includes:

e. The LCAS source finds a new channel that can be added to the VCG, and assigns a valid SQ to it as the SQ of the new channel. The SQ value of the new channel is the maximum of the SQ recorded in the VCG. Add 1 to the value; at the same time add 1 to the maximum value of the used SQ recorded by the VCG, as the maximum value of the used SQ newly recorded by the VCG.

Further, the method also includes:

f. Continue to inquire about other channels that can be added in the VCG. If there are channels that can be added in the VCG, go to step e.

Further, if it is found that there is no channel that can be added in the VCG, the method also includes:

g. LCAS finds a new channel to be added to the VCG, and allocates a temporary SQ that can be used to feed back the status information of the new channel to the new channel; the temporary SQ is the allocated SQ recorded by the VCG The maximum value of SQ is increased by one, and the maximum value of the allocated SQ of the VCG record is updated to be the maximum value of the allocated SQ of the original record plus one;

h. Continue to inquire about other channels to be added in the VCG. If there is a channel to be added in the VCG, jump to step g. If there is no channel to be added in the VCG, end SQ Reorder processing.

Further, the new channel that can be added to the VCG is specifically a channel that has sent an ADD command in the LCAS control frame and whose VC channel status report information indicates normal.

Further, the new channel to be added to the VCG is specifically the channel that will issue an ADD command in the LCAS control frame of the new channel.

Further, the status information of the new channel includes a channel deletion indication, a read-back channel status indication, an indication of preparing to add a channel, an SQ value of the channel, and an indication of completion of the current SQ rearrangement process.

Here, detecting the channel means reading the status information of the channel and judging the status of the channel. The used SQ refers to the SQ officially allocated to the VC channel. The allocated SQ refers to the used SQ and the temporarily allocated SQ. If there is no channel to be added, the maximum value of the used SQ recorded by the VCG is equal to the allocated The maximum value of the SQ, if there is a channel to be added, the maximum value of the used SQ recorded by the VCG is smaller than the maximum value of the allocated SQ.

According to the inherent characteristics of the LCAS protocol, the present invention, the SQs of all members in the VCG are fixed in one LCAS frame, and perform decentralized processing on the rearrangement of the SQs, that is, when the time slot corresponding to the physical channel is valid, the channel is rearranged SQ required for the next LCAS frame. That is to say, the present invention first processes the rearrangement of the deleted channels, then adds the channels, and finally processes the channels to be added; it can also add the channels first, then delete the channels, and finally process the channels to be added. The process is the same as the previous one. The invention not only realizes the processing of SQ by hardware, but also does not occupy too many logic resources. The present invention uses less logical resources to complete the rearrangement of SQ by hardware and greatly reduces the work of software. The software only needs to set the VCG to which the channel belongs and enable or disable the channel.

Description of drawings:

The present invention will be described in detail below in conjunction with the accompanying drawings.

Fig. 1 is a schematic diagram of the processing flow of the present invention;

Fig. 2 is a schematic circuit diagram of the present invention;

Fig. 3 is a circuit principle diagram of multiplexing VCG in the present invention.

Detailed ways:

As shown in Figure 1, when the VCG in the LCAS needs to add or delete channels, the source needs to complete the rearrangement of the SQs of the existing channels and allocate SQs for the newly added channels, and the SQs must be allocated in each LCAS multiframe. to rearrange. During the actual operation of the present invention, both channel deletion and channel addition can be processed first. Let's take the example of deleting the channel first. If you delete a channel, you need to cancel the SQ corresponding to this channel, which will create a vacancy in the SQ sequence, resulting in the discontinuity of the SQ. To ensure the continuity of the SQ, you need to rearrange the SQ. After querying the channel to be deleted, record the current SQ of the deleted channel as SQ_DEL, and set the SQ of the deleted channel to an invalid value. The deleted channel only affects those channels whose SQ value is greater than the recorded SQ_DEL, but once a channel to be deleted is inquired in the process of the present invention, no other channel to be deleted will be searched, and other channels of VCG need not be deleted for the time being . When rearranging, when other channels of the same VCG appear, obtain the SQ of the channel by checking its configuration table. If it is a valid SQ, compare it with the recorded SQ_DEL. If it is greater than the recorded SQ_DEL, update the channel’s SQ. SQ, set SQ=SQ-1, otherwise the SQ value of the channel remains unchanged. After all the channels of the VCG have been processed relative to the currently recorded SQ_DEL, update the VCG's SQ_MAX=SQ_MAX-1, where SQ_MAX represents the maximum value of the SQ recorded by the VCG. Query the next channel to be deleted and perform the same processing. After all the channels that need to be deleted are processed, the circuit completes the SQ rearrangement after the channel is deleted, and allocates the SQs for the added channels. For each completed channel addition preparation, that is, the ADD command has been issued in the LCAS control frame, and the VC channel status is normal, that is, the received VC channel status report indicates that the VC channel is normal, then the VC channel is officially added to the VCG , assign SQ=SQ_MAX+1, and update the SQ_MAX=SQ_MAX+1 recorded by VCG; after processing all the channels that need to be added, start processing the channels to be added, that is, the VC that is going to send the ADD command word in the control frame aisle. For each channel to be added, a temporary SQ needs to be allocated to read back the channel status report information. The allocated temporary SQ=SQ_TMP_MAX+1, where SQ_TMP_MAX represents the maximum value of the currently allocated SQ. The row sets the initial value of SQ_TMP_MAX to SQ_MAX. The queried channel status includes the channel deletion indication, the read-back channel status normal indication, the preparation to add channel indication, the SQ value and the current processing completion indication.

The present invention can also first complete the addition of new channels, the method is the same as the above method, then delete the channels, and then rearrange, the method is also the same as the above method, and finally process the channels to be added, the method is the same as the above method.

As shown in Fig. 2, the present invention can be realized through a comparison circuit and a multiplexer (MUX). Here, CURR_SQ represents the SQ of the current channel, SQ_NEW represents the updated SQ of the current channel, SQ_DEL represents the SQ of the deleted channel recorded by the VCG, SQ_MAX represents the maximum value of the SQ currently actually used by the VCG record, and SQ_TMP_MAX represents the maximum value of the SQ recorded by the VCG. The maximum value of the currently allocated SQ.

As shown in Figure 3, since SDH is a time-division system, multiple VCGs can share processing circuits in the present invention. In the figure, VCG_SEL is a VCG selection signal, which is used to select SQ_DEL, SQ_MAX, and SQ_TMP_MAX corresponding to the VCG to which the current channel belongs. SQ_DEL_1 to SQ_DEL_n respectively represent the SQ_DEL of n VCGs, SQ_MAX_1 to SQ_MAX_n respectively represent the SQ_MAX of n VCGs, and SQ_TMP_MAX_1 to SQ_TMP_MAX_n represent the SQ_TMP_MAX of n VCGs respectively.

As shown in Figures 2 and 3, LCAS detection needs to delete the VCG to which the channel belongs. Use VCG_SEL to select the SQ_DEL, SQ_MAX, and SQ_TMP_MAX corresponding to the VCG to which the current channel belongs. The comparison circuit compares CURR_SQ with the SQ_DEL to be deleted, and the comparison result is input to In another multiplexer MUX, the CURR_SQ is processed, that is, the value is kept unchanged (CURR_SQ is less than SQ_DEL) or subtracted by 1 (CURR_SQ is greater than SQ_DEL). 1 treatment. When adding a new channel to the VCG, add 1 to the SQ_MAX of the VCG, and give a temporary SQ to the channel to be added, that is, SQ_TMP_MAX+1. In this way, the present invention can quickly complete the rearrangement of VCG. The current processing stage in the figure indicates that it is currently processing the stage of deleting channels, adding channels, preparing to add channels, or the stage after SQ rearrangement processing is completed.

The present invention utilizes the characteristics of the SDH time-division system, and multiple VCGs can share one processing circuit. The present invention uses less logical resources to complete the rearrangement of SQ by hardware and greatly reduces the work of software. The software of the present invention only needs to set the VCG to which the channel belongs and enable or disable the channel.

Claims (8)

1. A method for rearranging the channel sequence number SQ in the source-end virtual capacity group in the link capacity adjustment scheme LCAS, characterized in that, the channel sequence number SQ in the source-end virtual capacity group in the link capacity adjustment scheme LCAS is re-arranged The method of row is realized by comparison circuit and multiplexer, and described method comprises the following steps: b. Start to query the VC channels of each virtual container in the current virtual capacity group VCG; after the LCAS source has inquired about a channel that needs to be deleted in the VCG, it will no longer search for other channels that need to be deleted, and record the current SQ of the channel as SQ_DEL, At the same time, update the SQ of the channel to an invalid value, and continue to step c; c. When rearranging, when other passages in the VCG appear, query the configuration table to obtain the SQ of the other passages, if the SQ of the other passages is a valid value, compare it with the recorded SQ_DEL of the VCG, If it is less than the SQ_DEL recorded by the VCG, then keep the SQ of the other channels unchanged; if it is greater than the SQ_DEL recorded by the VCG, then subtract 1 from the SQ of the other channels as its new SQ; all in the VCG After the processing of the channel relative to the currently recorded SQ_DEL is completed, subtract 1 from the maximum value of the SQ recorded in the VCG and use it as the maximum value of the SQ used by the newly recorded VCG. 2. the method for channel sequence number SQ rearrangement in the source end virtual capacity group in LCAS as claimed in claim 1, is characterized in that, this method also comprises: d. Continue to query other channels that need to be deleted in the VCG. If there is a channel that needs to be deleted in the VCG, then jump to the LCAS source in step b after querying the channel that needs to be deleted in the VCG. A step of. 3. the method for channel sequence number SQ rearrangement in the source end virtual capacity group in LCAS as claimed in claim 2, it is characterized in that, if inquiring does not have the channel that needs to be deleted in described VCG, this method also comprises: e. The LCAS source finds a new channel that can be added to the VCG, and assigns a valid SQ to it as the SQ of the new channel. The SQ value of the new channel is the maximum of the SQ recorded in the VCG. Add 1 to the value; at the same time add 1 to the maximum value of the used SQ recorded by the VCG, as the maximum value of the used SQ newly recorded by the VCG. 4. the method for channel sequence number SQ rearrangement in the source end virtual capacity group in LCAS as claimed in claim 3, it is characterized in that, this method also comprises: f. Continue to inquire about other channels that can be added in the VCG. If there are channels that can be added in the VCG, go to step e. 5. the method for channel serial number SQ rearrangement in the source end virtual capacity group in LCAS as claimed in claim 4, it is characterized in that, if inquiring does not have the channel that can add in the described VCG, this method also comprises: g. LCAS finds a new channel to be added to the VCG, and allocates a temporary SQ that can be used to feed back the status information of the new channel to the new channel; the temporary SQ is the allocated SQ recorded by the VCG The maximum value of SQ is increased by one, and the maximum value of the allocated SQ of the VCG record is updated to be the maximum value of the allocated SQ of the original record plus one; h. Continue to inquire about other channels to be added in the VCG. If there is a channel to be added in the VCG, jump to step g. If there is no channel to be added in the VCG, end SQ Reorder processing. 6. The method for channel SQ rearrangement in the source end virtual capacity group in LCAS as claimed in claim 3 or 4, it is characterized in that, the new channel that can be added in the described VCG is specifically sent out in the LCAS control frame The ADD command is passed and the VC channel status report information indicates a normal channel. 7. The method for rearranging the channel sequence number SQ in the source virtual capacity group in the LCAS as claimed in claim 5, wherein the new channel to be added to the VCG is specifically to be added to the new channel in the new channel. The channel through which the ADD command is issued in the LCAS control frame. 8. the method for channel serial number SQ rearrangement in the source end virtual capacity group in LCAS as claimed in claim 5, it is characterized in that, the state information of described new channel comprises channel deletion indication, the normal indication of the channel status of reading back, Prepare to add channel indication as well as the channel's SQ value and current SQ rearrangement processing completion indication.

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