CN105871453A - Method capable of realizing data service protection through OTN (optical transport networking) equipment - Google Patents
Method capable of realizing data service protection through OTN (optical transport networking) equipment Download PDFInfo
- Publication number
- CN105871453A CN105871453A CN201610354897.7A CN201610354897A CN105871453A CN 105871453 A CN105871453 A CN 105871453A CN 201610354897 A CN201610354897 A CN 201610354897A CN 105871453 A CN105871453 A CN 105871453A
- Authority
- CN
- China
- Prior art keywords
- data service
- gfp
- port
- otn
- csf
- 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
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
- H04B10/03—Arrangements for fault recovery
- H04B10/032—Arrangements for fault recovery using working and protection systems
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
- H04B10/07—Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems
- H04B10/075—Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems using an in-service signal
- H04B10/079—Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems using an in-service signal using measurements of the data signal
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
- H04B10/07—Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems
- H04B10/075—Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems using an in-service signal
- H04B10/079—Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems using an in-service signal using measurements of the data signal
- H04B10/0795—Performance monitoring; Measurement of transmission parameters
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04J—MULTIPLEX COMMUNICATION
- H04J3/00—Time-division multiplex systems
- H04J3/16—Time-division multiplex systems in which the time allocation to individual channels within a transmission cycle is variable, e.g. to accommodate varying complexity of signals, to vary number of channels transmitted
- H04J3/1605—Fixed allocated frame structures
- H04J3/1652—Optical Transport Network [OTN]
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L41/00—Arrangements for maintenance, administration or management of data switching networks, e.g. of packet switching networks
- H04L41/06—Management of faults, events, alarms or notifications
- H04L41/0631—Management of faults, events, alarms or notifications using root cause analysis; using analysis of correlation between notifications, alarms or events based on decision criteria, e.g. hierarchy, tree or time analysis
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L41/00—Arrangements for maintenance, administration or management of data switching networks, e.g. of packet switching networks
- H04L41/06—Management of faults, events, alarms or notifications
- H04L41/0654—Management of faults, events, alarms or notifications using network fault recovery
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04Q—SELECTING
- H04Q11/00—Selecting arrangements for multiplex systems
- H04Q11/0001—Selecting arrangements for multiplex systems using optical switching
- H04Q11/0005—Switch and router aspects
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04Q—SELECTING
- H04Q11/00—Selecting arrangements for multiplex systems
- H04Q11/0001—Selecting arrangements for multiplex systems using optical switching
- H04Q11/0062—Network aspects
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04Q—SELECTING
- H04Q11/00—Selecting arrangements for multiplex systems
- H04Q11/0001—Selecting arrangements for multiplex systems using optical switching
- H04Q11/0062—Network aspects
- H04Q2011/0079—Operation or maintenance aspects
- H04Q2011/0081—Fault tolerance; Redundancy; Recovery; Reconfigurability
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04Q—SELECTING
- H04Q11/00—Selecting arrangements for multiplex systems
- H04Q11/0001—Selecting arrangements for multiplex systems using optical switching
- H04Q11/0062—Network aspects
- H04Q2011/0079—Operation or maintenance aspects
- H04Q2011/0083—Testing; Monitoring
Abstract
The invention discloses a method capable of realizing data service protection through OTN (optical transport networking) equipment. The method comprises steps as follows: the state of a data service port and serious warning of the OTN overhead level are monitored in real time; a board card determines whether a GFP-CSF management frame is interposed in a GFP channel according to the real-time monitored warning state and the mapping mode of data services; the board card determines whether the GFP-CSF management frame in the demapping direction is monitored according to the mapping mode of data services; the board card determines whether C1C2 fixed code streams are interposed into a GE port of a router at the opposite end according to the monitored port state and the GFP-CSF state in the demapping direction; when all monitored warnings disappear, the C1C2 fixed code streams interposed into the data service port are canceled, so that the whole service channel recovers normal work. The method is adapted to various data service packaging forms, the condition that services cannot be recovered after failure disappears due to drop-dead halt cannot be caused, matching with OCP light power detection is not required, communication with the router and two-way protection can be completely realized, and the cost is lower.
Description
Technical field
The present invention relates to technical field of photo communication, be specifically related under a kind of OTN equipment realize data service
The method of protection.
Background technology
" 12 development plan " target specifies, during 12, China's urban family broadband reaches 20
More than million, rural households broadband reaches more than 4,000,000, uses mini-plant, has special line bandwidth upgrading
For the ability of FE/GE, based on ODUO granule flexible dispatching and possess OTN (Optical Transport
Networking, optical transfer network) device of system perfecting protection mechanism becomes the concern of operator deployment
Point, OTN equipment realizes Ethernet LAG (Link Aggregation, link aggregation) protection, uses
By the Physical Layer Convergence mode of IEEE802.3ah protocol definition, define more complicated ethernet frame
Burst and recombination function.In theory, to provide multilink between node device faster for Physical Layer Convergence
Function is all carried on a shoulder pole in protection and load in hgher efficiency, and this just requires that OTN equipment self can pass through some scheme
When realizing breaking down with client-side device intercommunication, can guarantee that and two-way can cut off business.
Traditional OTN equipment many employings OCP (optical channel layers protection) realizes corresponding customer side and accesses industry
The protection of business, this guard method needs user to add OCP board to realize the concurrently choosing receipts of business, increasing
Add the networking cost of user.
There is multiple mapping mode in online online data service, in addition to the ODUO of standard maps, also
There is the old equipment of substantial amounts of other mapping mode of use, the mapping mode that they use substantially has two kinds:
One is by GE by GFP (Generic Framing Procedure, Generic Framing Procedure) agreement
Business is mapped to STM-N (Synchronous Transport Module level N, synchronous transfer mould
Block n level) in, then re-map in OPU；Two is GE business by GFP agreement directly encapsulates and reflects
In the channel time slot being mapped to OPU1/OPU2, re-map and be multiplexed into ODU1/ODU2 channel signal.For
To reducing the consideration of user networking cost, and the multiple mapped mode of GE business the present situation deposited on gauze,
Need to propose a kind of data service protection method of unified low cost.
Summary of the invention
The technical problem to be solved is that the existing data service protection method of solution can not be simultaneously
The most online compatible multiple business mapping mode, and relatively costly problem.
In order to solve above-mentioned technical problem, the technical solution adopted in the present invention is to provide a kind of OTN and sets
The standby lower method realizing data service protection, comprises the following steps:
Step 101: the state of Real-time Monitoring Data service port and the serious announcement of OTN expense aspect
Alert；
Step 102: the board of bearing data service is according to the alarm status real-time monitored and data industry
The mapping mode of business, decides whether to be inserted into GFP_CSF according to G.7041 agreement at corresponding GFP passage
Management frame；
Step 103: the board of bearing data service decides whether according to the mapping mode of current data service
The GFP_CSF in monitoring demapping direction manages frame；
Step 104: the board of bearing data service is according to the port status real-time monitored and demapping
The state of direction GFP_CSF, decides whether to insert to the GE port of end-to-end router to meet 802.3 associations
The C1C2 of view fixes code stream so that in the router side port service docked with this board data service port
Break thus complete whole business switching action；
Step 105: after all alarms real-time monitored disappear, inserts under cancellation data service port
C1C2 fixes code stream so that whole service channel recovers normal work.
In the above-mentioned methods, judge that the condition that alarm disappears is to be not received by for continuous 3 seconds at receiving terminal
Corresponding GFP manages frame.
In the above-mentioned methods, for the data service using GE_TTT to map, when at data service port
When real-time monitoring LOS, Linkdown or OTN expense fault, by the data code flow in RX/TX direction
All replace with C1C2 fixed sequence program.
In the above-mentioned methods, when OTUA monitors GFP_RDI or PM_BDI, at data service end
Mouth inserts LFI；When OTUB monitors OTN fault alarm or GFP_CSF, at data service port
Insert LFI；When monitoring RF alarm at data service port, map direction in business and insert
GFP_RDI。
In the above-mentioned methods, the insertion condition of LFI gets rid of the Linkdown alarm of data service port.
The present invention, for the data service using GE_TTT to map, replaces with data service signal
C1C2 fixed sequence program, for using the data service of GFP_F/GFP_T encapsulation, then uses GFP management
Frame transmission warning information, inserts LFI at data service port simultaneously and completes to switch work, the method
Adapted to the packing forms of multiple data service, do not have be absorbed in endless loop and after causing trouble disappears
The problem that business cannot be recovered, it is not required that coordinate the luminous power detection of OCP to realize, can be complete
Realize with router to logical and bidirectional protective, the most online the most compatible multiple business mapping mode,
And cost is relatively low.
Accompanying drawing explanation
The method realizing data service protection under a kind of OTN equipment that Fig. 1 provides for the embodiment of the present invention
Flow chart；
Fig. 2 uses the protection of GFP_T/GFP_F encapsulation to show for the data service that the embodiment of the present invention provides
It is intended to.
Detailed description of the invention
Below in conjunction with specification drawings and specific embodiments, the present invention is described in detail.
Embodiments provide a kind of method realizing data service protection under OTN equipment, for
Use the data service of GFP_F/GFP_T encapsulation, as it is shown in figure 1, said method comprising the steps of:
The serious announcement of step 101, the state of Real-time Monitoring Data service port and OTN expense aspect
Alert.
Step 102, bearing data service board according to the alarm status real-time monitored and data industry
The mapping mode of business, decides whether to be inserted into GFP_CSF according to G.7041 agreement at corresponding GFP passage
Management frame.
Fig. 2 uses the protection of GFP_T/GFP_F encapsulation to show for the data service that the embodiment of the present invention provides
Being intended to, as in figure 2 it is shown, GFP_CSF and GFP_RDI is GFP layer-management frame, transmitting terminal uses
100 millisecond periods insert, and judge that the condition that alarm disappears is to be not received by for continuous 3 seconds at receiving terminal
Corresponding GFP manages frame.
When OTUA monitors GFP_RDI or PM_BDI, insert LFI at data service port；When
When OTUB monitors OTN fault alarm or GFP_CSF, insert LFI at data service port；When
When data service port monitors RF (Remote Fault) alarm, map direction in business and insert
GFP_RDI, described RF alarm is defined in IEEE802.3 agreement, by the route supporting this function
Device inserts, and the receiving terminal at OTN board FPDP can monitor this alarm.
The insertion condition of LFI (Link Fault Indication, link failure indicates) should get rid of number
Alert according to the Linkdown of service port, open auto-negotiation function and cause getting rid of end-to-end router port
Relay protective scheme enters deadlock state cannot recover business.
Step 103, the board of bearing data service decide whether according to the mapping mode of current data service
The GFP_CSF in monitoring demapping direction manages frame.
Step 104, bearing data service board according to the port status real-time monitored and demapping
Direction GFP_CSF state, decides whether to insert to the GE port of end-to-end router to meet 802.3 agreements
C1C2 fix code stream so that the router port service disconnection docked with this board data service port
Thus complete whole data service switching action.
Step 105, after all alarms real-time monitored disappear, cancel and inserting under data service port
C1C2 fixes code stream so that whole service channel recovers normal work.
For the data service using GE_TTT to map, when real-time monitoring LOS at data service port
During (circuit optical signal loss)/Linkdown or OTN expense fault, by the numeric data code in RX/TX direction
Stream all replaces with C1C2 fixed sequence program, owing to GE_TTT maps lower data service signal at OTN network
In be transparent transmission, so C1C2 fixed sequence program can through OTN network arrive opposite side router
Realize two-way switching, when cancelling C1C2 code stream replacement data service signal, business recovery after failure vanishes
Normally.
The present invention, for the data service using GE_TTT to map, according to G.709 standard by data industry
Business signal replaces with C1C2 fixed sequence program, for using the data service of GFP_F/GFP_T encapsulation, then
Use GFP management frame transmission warning information, insert LFI at data service port simultaneously and complete to switch
Work, the method has adapted to multiple data service packing forms, has not had and be absorbed in endless loop and cause
The problem that after failure vanishes, business cannot be recovered, it is not required that coordinate the luminous power detection of OCP to realize,
Can be fully achieved with router to logical and bidirectional protective, the multiple business on the most compatible gauze is reflected
Penetrate mode, and cost is relatively low.
The present invention is not limited to above-mentioned preferred forms, and anyone should learn the enlightenment in the present invention
Under the structure change made, every have same or like technical scheme with the present invention, each falls within this
Within the protection domain of invention.
Claims (5)
1. the method realizing data service protection under an OTN equipment, it is characterised in that described method
Comprise the following steps:
Step 101: the state of Real-time Monitoring Data service port and the serious announcement of OTN expense aspect
Alert；
Step 102: the board of bearing data service is according to the alarm status real-time monitored and data industry
The mapping mode of business, decides whether to be inserted into GFP_CSF according to G.7041 agreement at corresponding GFP passage
Management frame；
Step 103: the board of bearing data service decides whether according to the mapping mode of current data service
The GFP_CSF in monitoring demapping direction manages frame；
Step 104: the board of bearing data service is according to the port status real-time monitored and demapping
The state of direction GFP_CSF, decides whether to insert to the GE port of end-to-end router to meet 802.3 associations
The C1C2 of view fixes code stream so that in the router side port service docked with this board data service port
Break thus complete whole business switching action；
Step 105: after all alarms real-time monitored disappear, inserts under cancellation data service port
C1C2 fixes code stream so that whole service channel recovers normal work.
2. the method for claim 1, it is characterised in that judge what alarm disappeared at receiving terminal
Condition is that the GFP being not received by correspondence for continuous 3 seconds manages frame.
3. the method for claim 1, it is characterised in that also include:
For use GE_TTT map data service, when data service port real-time monitor LOS,
During Linkdown or OTN expense fault, the data code flow in RX/TX direction is all replaced with C1C2 and fixes
Sequence.
4. the method for claim 1, it is characterised in that when OTUA monitors GFP_RDI
Or during PM_BDI, insert LFI at data service port；When OTUB monitor OTN fault alarm or
During GFP_CSF, insert LFI at data service port；When monitoring RF alarm at data service port
Time, map direction in business and insert GFP_RDI.
5. method as claimed in claim 4, it is characterised in that the insertion condition of LFI gets rid of data
The Linkdown alarm of service port.
Priority Applications (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610354897.7A CN105871453B (en) | 2016-05-25 | 2016-05-25 | A kind of method that data service protection is realized under OTN equipment |
| MYPI2018703800A MY194976A (en) | 2016-05-25 | 2016-05-25 | Method implementing data service protection in otn device |
| PCT/CN2017/075535 WO2017202100A1 (en) | 2016-05-25 | 2017-03-03 | Method implementing data service protection in otn device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610354897.7A CN105871453B (en) | 2016-05-25 | 2016-05-25 | A kind of method that data service protection is realized under OTN equipment |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN105871453A true CN105871453A (en) | 2016-08-17 |
| CN105871453B CN105871453B (en) | 2018-04-20 |
Family
ID=56641338
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201610354897.7A Active CN105871453B (en) | 2016-05-25 | 2016-05-25 | A kind of method that data service protection is realized under OTN equipment |
Country Status (3)
| Country | Link |
|---|---|
| CN (1) | CN105871453B (en) |
| MY (1) | MY194976A (en) |
| WO (1) | WO2017202100A1 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2017202100A1 (en) * | 2016-05-25 | 2017-11-30 | 烽火通信科技股份有限公司 | Method implementing data service protection in otn device |
| CN107579796A (en) * | 2017-09-21 | 2018-01-12 | 烽火通信科技股份有限公司 | The clock processing unit and method of a kind of OTN branch roads board |
| CN113114406A (en) * | 2021-03-11 | 2021-07-13 | 烽火通信科技股份有限公司 | Method, device, equipment and storage medium for preventing deadlock of OTN optical channel protection |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20060187845A1 (en) * | 2005-02-18 | 2006-08-24 | Alcatel | Failure management and propagation in a telecommunication network |
| CN103209021A (en) * | 2013-04-11 | 2013-07-17 | 烽火通信科技股份有限公司 | Two-way protection method of symmetrical system of GFP (Generic Framing Procedure) frame mapping encapsulation business |
| CN103746738A (en) * | 2014-01-10 | 2014-04-23 | 烽火通信科技股份有限公司 | Method for realizing two-way service interruption by GFP (Generic Framing Procedure) frame transmission |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7898944B2 (en) * | 2005-12-14 | 2011-03-01 | Cisco Technology, Inc. | Smart mechanism for multi-client bidirectional optical channel protection scheme |
| CN1983931A (en) * | 2006-04-05 | 2007-06-20 | 华为技术有限公司 | Method and system for transmitting fault information in light network |
| CN101662398B (en) * | 2009-10-14 | 2012-01-04 | 烽火通信科技股份有限公司 | Method for transferring alarm of client access link in transmission system |
| CN101951532B (en) * | 2010-09-07 | 2013-06-12 | 华为技术有限公司 | Transmission and acquirement method, device and system of OTN (Optical Transport Network) network business defect information |
| MY194976A (en) * | 2016-05-25 | 2022-12-29 | Fiberhome Telecommunication Tech Co Ltd | Method implementing data service protection in otn device |
-
2016
- 2016-05-25 MY MYPI2018703800A patent/MY194976A/en unknown
- 2016-05-25 CN CN201610354897.7A patent/CN105871453B/en active Active
-
2017
- 2017-03-03 WO PCT/CN2017/075535 patent/WO2017202100A1/en active Application Filing
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20060187845A1 (en) * | 2005-02-18 | 2006-08-24 | Alcatel | Failure management and propagation in a telecommunication network |
| CN103209021A (en) * | 2013-04-11 | 2013-07-17 | 烽火通信科技股份有限公司 | Two-way protection method of symmetrical system of GFP (Generic Framing Procedure) frame mapping encapsulation business |
| CN103746738A (en) * | 2014-01-10 | 2014-04-23 | 烽火通信科技股份有限公司 | Method for realizing two-way service interruption by GFP (Generic Framing Procedure) frame transmission |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2017202100A1 (en) * | 2016-05-25 | 2017-11-30 | 烽火通信科技股份有限公司 | Method implementing data service protection in otn device |
| CN107579796A (en) * | 2017-09-21 | 2018-01-12 | 烽火通信科技股份有限公司 | The clock processing unit and method of a kind of OTN branch roads board |
| CN107579796B (en) * | 2017-09-21 | 2019-04-26 | 烽火通信科技股份有限公司 | A kind of the clock processing unit and method of OTN branch board |
| CN113114406A (en) * | 2021-03-11 | 2021-07-13 | 烽火通信科技股份有限公司 | Method, device, equipment and storage medium for preventing deadlock of OTN optical channel protection |
| CN113114406B (en) * | 2021-03-11 | 2022-08-05 | 烽火通信科技股份有限公司 | Method, device, equipment and storage medium for preventing deadlock of OTN optical channel protection |
Also Published As
| Publication number | Publication date |
|---|---|
| CN105871453B (en) | 2018-04-20 |
| WO2017202100A1 (en) | 2017-11-30 |
| MY194976A (en) | 2022-12-29 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US10425153B2 (en) | Generalized service protection systems and methods | |
| CN101753453B (en) | Networking method for ring network of packet transport network | |
| CN103209099B (en) | A kind of automatic switching protection method of internodal network communication circuit | |
| EP2501084B1 (en) | Transmission multi-protocol label switching network system and link protection method | |
| GB2471761A (en) | Fault recovery path reconfiguration in ring networks | |
| US20170180153A1 (en) | Systems and methods to detect and recover from a loop in an ethernet ring protected network | |
| US9825696B2 (en) | Ethernet link state signaling for packet flows mapped into optical transport network with generic framing procedure | |
| CN101662398B (en) | Method for transferring alarm of client access link in transmission system | |
| US20130121683A1 (en) | Apparatus and method for determining a location of failure in a transmission network | |
| US20120092985A1 (en) | Ten gigabit ethernet port protection systems and methods | |
| CN102291631A (en) | Hybrid access and transmission method and device of packet switching and optical transport network service | |
| CN101924654A (en) | Point-to-multipoint service-based path switching method and system | |
| CN104393914A (en) | A multiplex route recovering method for an optical fiber differential protection device | |
| CN105871453A (en) | Method capable of realizing data service protection through OTN (optical transport networking) equipment | |
| CN109787895A (en) | A kind of dual-homing protection method, access node, equipment and communication network | |
| CN101022388A (en) | Method for constituting self-healing ring with ordinery Ethernet technique | |
| US7751335B2 (en) | Failure handling system | |
| CN110290042A (en) | Transfers net system for rail traffic | |
| CN102710482B (en) | Method and device for looped network protection | |
| CN102104519A (en) | Ring network restoring method and device based on topology information | |
| CN101155133B (en) | Processing method for information of flux project periodic line | |
| CN107579796B (en) | A kind of the clock processing unit and method of OTN branch board | |
| CN102546204B (en) | The transmission method of TDM circuit emulation service remote alarm information and system | |
| CN103546321A (en) | RPR energy-saving management method and device | |
| CN104219066B (en) | A kind of method for multicast communication of Wide area protection system data network |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |