Imininingwane yokusetshenziswa yephrothokholi yokuvumelanisa ye-PTPv2

Isingeniso

Umqondo wokwakha "Isiteshi Sedijithali" embonini yamandla kagesi udinga ukuvumelanisa ngokunemba kwe-1 μs. Imisebenzi yezezimali nayo idinga ukunemba kwe-microsecond. Kulezi zinhlelo zokusebenza, ukunemba kwesikhathi se-NTP akusanele.

Iphrothokholi yokuvumelanisa ye-PTPv2, echazwe izinga le-IEEE 1588v2, ivumela ukunemba kokuvumelanisa kwamashumi amaningana ama-nanoseconds. I-PTPv2 ikuvumela ukuthi uthumele amaphakethe okuvumelanisa ngamanethiwekhi e-L2 ne-L3.

Izindawo eziyinhloko lapho i-PTPv2 isetshenziswa khona yilezi:

• amandla;
• izinto zokulawula nezokukala;
• inkimbinkimbi yezempi-yezimboni;
• ucingo;
• umkhakha wezezimali.

Lokhu okuthunyelwe kuchaza ukuthi iphrothokholi yokuvumelanisa ye-PTPv2 isebenza kanjani.

Sinolwazi oluthe xaxa embonini futhi sivamise ukubona le phrothokholi ekusetshenzisweni kwamandla. Ngokufanelekile, sizokwenza isibuyekezo ngokuqapha ukuze uthole amandla.

Kungani kudingekile?

Okwamanje, i-STO 34.01-21-004-2019 ye-PJSC Rosseti kanye ne-STO 56947007-29.240.10.302-2020 ye-PJSC FGC UES iqukethe izimfuneko zokuhlela ibhasi lenqubo nokuvumelanisa isikhathi nge-PTPv2.

Lokhu kungenxa yokuthi amatheminali okuvikela i-relay kanye namadivayisi wokulinganisa axhunywe ebhasini lenqubo, elidlulisa amanani amanje kanye ne-voltage ngebhasi lenqubo, kusetshenziswa lokho okubizwa ngokuthi imifudlana ye-SV (ukusakaza okuningi).

Amatheminali okuvikela i-relay asebenzisa lawa manani ukwenza ukuvikelwa kwe-bay. Uma ukunemba kwezilinganiso zesikhathi kukuncane, khona-ke okunye ukuvikela kungase kusebenze amanga.

Isibonelo, ukuzivikela kokukhetha okuphelele kungase kube isisulu sokuvumelanisa isikhathi "esibuthakathaka". Ngokuvamile ukucabanga okunjalo kokuzivikela kusekelwe ekuqhathaniseni amanani amabili. Uma amanani ehluka ngenani elikhulu ngokwanele, khona-ke ukuvikela kuyaqalwa. Uma lawa manani akalwa ngokunemba kwesikhathi okungu-1 ms, khona-ke ungathola umehluko omkhulu lapho amanani empeleni ejwayelekile uma kulinganiswa ngokunemba kuka-1 μs.

Izinguqulo ze-PTP

Iphrothokholi ye-PTP ekuqaleni yachazwa ngo-2002 ngokwezinga le-IEEE 1588-2002 futhi yayibizwa ngokuthi “Standard for a Precision Clock Synchronization Protocol for Networked Measurement and Control Systems.” Ngo-2008, kwakhululwa izinga elibuyekeziwe le-IEEE 1588-2008, elichaza inguqulo 2 ye-PTP. Le nguqulo yephrothokholi yathuthukisa ukunemba nokuzinza, kodwa ayizange igcine ukuhambisana okusemuva nenguqulo yokuqala yephrothokholi. Futhi, ngo-2019, kwakhululwa inguqulo yezinga le-IEEE 1588-2019, echaza i-PTP v2.1. Le nguqulo yengeza ukuthuthukiswa okuncane ku-PTPv2 futhi ibuyela emuva iyahambisana ne-PTPv2.

Ngamanye amazwi, sinesithombe esilandelayo esinezinguqulo:

I-PTPv1
(IEEE 1588-2002)

I-PTPv2
(IEEE 1588-2008)

I-PTPv2.1
(IEEE 1588-2019)

I-PTPv1 (IEEE 1588-2002)

-
Akuhambisani

Akuhambisani

I-PTPv2 (IEEE 1588-2008)

Akuhambisani

-
Iyahambisana

I-PTPv2.1 (IEEE 1588-2019)

Akuhambisani

Iyahambisana

-

Kodwa, njengenjwayelo, kukhona ama-nuances.

Ukungahambisani phakathi kwe-PTPv1 ne-PTPv2 kusho ukuthi idivayisi enikwe amandla i-PTPv1 ngeke ikwazi ukuvumelanisa newashi elinembile elisebenza ku-PTPv2. Basebenzisa amafomethi emiyalezo ahlukene ukuze bavumelanise.

Kodwa kusengenzeka ukuhlanganisa amadivayisi ne-PTPv1 namadivayisi ane-PTPv2 kunethiwekhi efanayo. Ukufeza lokhu, abanye abakhiqizi bayakuvumela ukuthi ukhethe inguqulo yephrothokholi kumachweba wewashi onqenqemeni. Okusho ukuthi, iwashi lomngcele lingavumelanisa lisebenzisa i-PTPv2 futhi lisavumelanise amanye amawashi axhunywe kulo lisebenzisa kokubili i-PTPv1 ne-PTPv2.

Amadivayisi we-PTP. Ziyini futhi zihluke kanjani?

Izinga le-IEEE 1588v2 lichaza izinhlobo ezimbalwa zamadivayisi. Zonke zikhonjisiwe etafuleni.

Amadivayisi axhumana wodwa nge-LAN esebenzisa i-PTP.

Imishini ye-PTP ibizwa ngokuthi amawashi. Wonke amawashi athatha isikhathi esiqondile ewashini likagogo.

Kunezinhlobo ezi-5 zamawashi:

Iwashi likagogo

Umthombo oyinhloko wesikhathi esinembile. Ngokuvamile ifakwe isixhumi esibonakalayo sokuxhuma i-GPS.

Iwashi Elijwayelekile

Idivayisi yembobo eyodwa engaba inkosi (iwashi eliyinhloko) noma isigqila (iwashi lesigqila)

Iwashi eliyinhloko (master)

Angumthombo wesikhathi esiqondile amanye amawashi avumelaniswa ngaso

Iwashi lesigqila

Qeda idivayisi evumelaniswe kusukela ewashi eliyinhloko

Iwashi Lomngcele

Idivayisi enezimbobo eziningi ezingaba inkosi noma isigqila.

Okusho ukuthi, lawa mawashi angakwazi ukuvumelanisa kusukela ewashini eliyinhloko futhi avumelanise amawashi ezigqila angaphansi.

Iwashi elibonisa ngale ekupheleni kuya ekupheleni

Idivayisi enezimbobo eziningi okungelona iwashi eliyinhloko noma isigqila. Idlulisela idatha ye-PTP phakathi kwamawashi amabili.

Lapho uthumela idatha, iwashi elibonisa ngale lilungisa yonke imilayezo ye-PTP.

Ukulungisa kwenzeka ngokwengeza isikhathi sokulibaziseka kule divayisi endaweni yokulungisa kunhlokweni yomlayezo odlulisiwe.

Iwashi elibonisa ngale kontanga kuya kontanga

Idivayisi enezimbobo eziningi okungelona iwashi eliyinhloko noma isigqila.
Idlulisela idatha ye-PTP phakathi kwamawashi amabili.

Lapho uthumela idatha, iwashi elibonisa ngale lilungisa yonke imilayezo ye-PTP Vumelanisa kanye Nokulandelela (okuningi mayelana nayo ngezansi).

Ukulungiswa kufinyelelwa ngokwengeza endaweni yokulungisa yephakethe elidluliswayo ukubambezeleka kudivayisi yokudlulisela kanye nokubambezeleka kwesiteshi sokudlulisa idatha.

I-Management Node

Idivayisi elungiselela futhi exilonga amanye amawashi

Amawashi ayinhloko nawesigqila avumelaniswa kusetshenziswa izitembu zesikhathi emilayezweni ye-PTP. Kunezinhlobo ezimbili zemilayezo kuphrothokholi ye-PTP:

• Imilayezo yomcimbi iyimiyalezo evumelanisiwe ehlanganisa ukukhiqiza isitembu sesikhathi ngesikhathi umlayezo uthunyelwa nangesikhathi owamukelwa ngaso.
• Imilayezo Ejwayelekile - Le milayezo ayidingi izitembu zesikhathi, kodwa ingase iqukathe izitembu zesikhathi zemilayezo ehlobene

Imiyalezo Yomcimbi

Imilayezo ejwayelekile

Vumelanisa
I-Delay_Req
I-Pdelay_Req
I-Pdelay_Resp

Memezela
Landelela
Delay_Resp
I-Pdelay_Resp_Follow_Up
Ukuphathwa
Iyasayina

Zonke izinhlobo zemilayezo kuzoxoxwa ngazo kabanzi ngezansi.

Izinkinga eziyisisekelo zokuvumelanisa

Uma iphakethe lokuvumelanisa lidluliswa ngenethiwekhi yendawo, libambezeleka eswitshi nakusixhumanisi sedatha. Noma iyiphi iswishi izokhiqiza ukubambezeleka okungama-microsecond angu-10, okungamukeleki ku-PTPv2. Ngemuva kwakho konke, sidinga ukufeza ukunemba kwe-1 μs kudivayisi yokugcina. (Lokhu uma sikhuluma ngamandla. Ezinye izinhlelo zokusebenza zingadinga ukunemba okukhulu.)

I-IEEE 1588v2 ichaza ama-algorithms ambalwa wokusebenza akuvumela ukuthi urekhode ukubambezeleka kwesikhathi futhi ukulungise.

Umsebenzi we-algorithm
Ngesikhathi sokusebenza okujwayelekile, iphrothokholi isebenza ngezigaba ezimbili.

• Isigaba 1 - ukusungula isigaba "Iwashi Eliyinhloko - Iwashi Lezigqila".
• Isigaba 2 - ukuvumelanisa kwewashi kusetshenziswa indlela yokuqeda ukuya ekupheleni noma i-Peer-to-Peer.

Isigaba 1 - Ukusungula Ukulawulwa Kwezigqila Eziyinhloko

Imbobo ngayinye yewashi elivamile noma elisemaphethelweni linenani elithile lezifunda (iwashi lesigqila newashi eliyinhloko). Izinga lichaza i-algorithm yoshintsho phakathi kwalezi zifundazwe. Ekuhlelweni, i-algorithm enjalo ibizwa ngokuthi umshini wesimo esilinganiselwe noma umshini wombuso (imininingwane eyengeziwe ku-Wiki).

Lo mshini wezwe usebenzisa i-Best Master Clock Algorithm (BMCA) ukuze usethe okuyinhloko lapho uxhuma amawashi amabili.

Le algorithm ivumela iwashi ukuthi lithathe imithwalo yemfanelo yewashi lika-grandmaster uma iwashi lika-Grandmaster lilahlekelwa isignali ye-GPS, lingaxhunyiwe ku-inthanethi, njll.

Izinguquko zesimo ngokuya nge-BMCA zifinyezwa kumdwebo olandelayo:


Ulwazi mayelana newashi ngakolunye uhlangothi "lwentambo" luthunyelwa ngomlayezo okhethekile (Memezela umlayezo). Uma lolu lwazi selutholiwe, i-algorithm yomshini wombuso iyasebenza futhi kwenziwa ukuqhathanisa ukuze kubonakale ukuthi yiliphi iwashi elingcono. Itheku ewashini elingcono kakhulu liba iwashi eliyinhloko.

Ukulandelana kwezikhundla okulula kukhonjisiwe kumdwebo ongezansi. Imizila 1, 2, 3, 4, 5 ingase iqukathe iwashi elibonisa ngale, kodwa abahlanganyeli ekusunguleni Iwashi Eliyinhloko - isigaba sewashi lesigqila.

Isigaba sesi-2 - Vumelanisa amawashi avamile nawonqenqema

Ngokushesha ngemva kokusungula isigaba se-"Master Clock - Slave Clock", isigaba sokuvumelanisa samawashi avamile kanye nemingcele siyaqala.

Ukuze uvumelanise, iwashi eliyinhloko lithumela umlayezo oqukethe isitembu sesikhathi ewashini lesigqila.

Iwashi eliyinhloko lingaba:

• isigaba esisodwa;
• izigaba ezimbili.

Amawashi esiteji esisodwa athumela umyalezo owodwa wokuvumelanisa ukuze uvumelanise.

Iwashi elinezigaba ezimbili lisebenzisa imilayezo emibili yokuvumelanisa - Vumelanisa kanye Nokulandelela.

Izindlela ezimbili zingasetshenziswa esigabeni sokuvumelanisa:

• Libazisa indlela yokuphendula isicelo.
• Indlela yokulinganisa ukubambezeleka kontanga.

Okokuqala, ake sibheke lezi zindlela esimweni esilula - lapho amawashi asobala engasetshenziswa.

Libazisa indlela yokuphendula isicelo

Lo mshini uhlanganisa izinyathelo ezimbili:

1. Ukulinganisa ukubambezeleka kokudlulisa umlayezo phakathi kwewashi eliyinhloko newashi lesigqila. Kwenziwe kusetshenziswa indlela yokuphendula isicelo sokulibaziseka.
2. Ukulungiswa kokushintsha kwesikhathi okuqondile kuyenziwa.

Isilinganiso sokubambezeleka


t1 - Isikhathi sokuthumela umlayezo wokuvumelanisa ngewashi eliyinhloko; t2 - Isikhathi sokwamukela umlayezo wokuvumelanisa ngewashi lesigqila; t3 - Isikhathi sokuthumela isicelo sokulibaziseka (Delay_Req) ​​ngewashi lesigqila; t4 - Delay_Req isikhathi sokwamukela ngewashi eliyinhloko.

Lapho iwashi lesigqila lazi izikhathi t1, t2, t3, kanye no-t4, lingakwazi ukubala ukulibaziseka okumaphakathi lapho lithumela umlayezo wokuvumelanisa (tmpd). Ibalwa kanje:

Lapho uthumela umlayezo Wokuvumelanisa Nokulandelela, ukubambezeleka kwesikhathi kusuka kunkosi kuya encekwini kuyabalwa - t-ms.

Lapho uthumela imilayezo ye-Delay_Req kanye ne-Delay_Resp, ukubambezeleka kwesikhathi kusuka encekwini kuya kunkosi kuyabalwa - t-sm.

Uma kwenzeka i-asymmetry ethile phakathi kwalawa manani amabili, khona-ke iphutha ekulungiseni ukuchezuka kwesikhathi esiqondile liyavela. Iphutha libangelwa ukuthi ukubambezeleka okubaliwe kuyisilinganiso sokulibaziseka kuka-t-ms no-t-sm. Uma ukubambezeleka kungalingani, ngakho-ke ngeke silungise isikhathi ngokunembile.

Ukulungiswa kokushintsha kwesikhathi

Lapho ukubambezeleka phakathi kwewashi eliyinhloko kanye newashi lesigqila sekwaziwa, iwashi lesigqila lenza ukulungisa isikhathi.

Amawashi ezigqila asebenzisa umlayezo Wokuvumelanisa kanye nomlayezo ozikhethela othi Landela_Up ukuze abale isikhathi esiqondile sokulinganisa lapho uthumela iphakethe lisuka kunkosi liya emawashini ezinceku. I-shift ibalwa kusetshenziswa ifomula elandelayo:

Indlela yokulinganisa ukubambezeleka kontanga

Lo mshini futhi usebenzisa izinyathelo ezimbili zokuvumelanisa:

1. Amadivayisi akala ukubambezeleka kwesikhathi kubo bonke omakhelwane kuzo zonke izimbobo. Ukwenza lokhu basebenzisa indlela yokubambezeleka kontanga.
2. Ukulungiswa kweshifu yesikhathi esiqondile.

Ukulinganisa ukubambezeleka phakathi kwamadivayisi asekela Imodi Yontanga-kuya-Kontanga

Ukubambezeleka phakathi kwezimbobo ezisekela indlela yontanga kuya kontanga kukalwa kusetshenziswa imilayezo elandelayo:

Uma imbobo 1 yazi izikhathi ezithi t1, t2, t3 kanye no-t4, ingabala ukubambezeleka okumaphakathi (tmld). Ibalwa kusetshenziswa ifomula elandelayo:

Imbobo ibe isisebenzisa leli nani lapho ibala inkambu yokulungisa yomlayezo ngamunye Wokuvumelanisa noma umyalezo ozikhethela wokuthi Landela_Up odlula kudivayisi.

Isamba sokubambezeleka sizolingana nesamba sokubambezeleka phakathi nokudluliselwa ngale divayisi, ukulibaziseka okumaphakathi ngesikhathi sokudlulisela ngesiteshi sedatha nokubambezeleka osekuvele qukethwe kulo mlayezo, okunikwe amandla kumadivayisi akhuphukayo.

Imilayezo ethi Pdelay_Req, Pdelay_Resp kanye ne-Pdelay_Resp_Follow_Up yokuzithandela ikuvumela ukuthi uthole ukubambezeleka kusuka kunkosi kuya kwesigqila futhi kusukela kusigqila kuye kwesinye (isiyingi).

Noma iyiphi i-asymmetry phakathi kwalawa manani amabili izokwethula iphutha lokulungiswa kwe-offset yesikhathi.

Ukulungisa ukushintshwa kwesikhathi esiqondile

Amawashi ezigqila asebenzisa umlayezo Wokuvumelanisa kanye nomlayezo ozikhethela othi Landela_Up ukuze abale isikhathi esiqondile sokulinganisa lapho uthumela iphakethe lisuka kunkosi liya emawashini ezinceku. I-shift ibalwa kusetshenziswa ifomula elandelayo:

Ukulungiswa kwezinzuzo zendlela yontanga-kuya-kontanga - ukubambezeleka kwesikhathi komlayezo ngamunye Wokuvumelanisa noma Ukulandela_kubalwa njengoba udluliselwa kunethiwekhi. Ngakho-ke, ukushintsha indlela yokudlulisela ngeke kuthinte nganoma iyiphi indlela ukunemba kokulungiswa.

Uma usebenzisa lo mshini, ukuvumelanisa isikhathi akudingi ukubala ukubambezeleka kwesikhathi endleleni enqanyulwa iphakethe lokuvumelanisa, njengoba kwenziwa ekushintshisaneni okuyisisekelo. Labo. Imilayezo yeDelay_Req neDelay_Resp ayithunyelwa. Ngale ndlela, ukubambezeleka phakathi kwewashi eliyinhloko nelesigqila kumane kufinyezwe emkhakheni wokulungisa womlayezo ngamunye Wokuvumelanisa noma Ukulandela_Up.

Enye inzuzo ukuthi iwashi eliyinhloko likhululekile esidingweni sokucubungula imilayezo ye-Delay_Req.

Izindlela zokusebenza zamawashi abonisa ngale

Ngokuvumelana nalokho, lezi kwakuyizibonelo ezilula. Manje ake sithi amaswishi avela endleleni yokuvumelanisa.

Uma usebenzisa amaswishi ngaphandle kosekelo lwe-PTPv2, iphakethe lokuvumelanisa lizobambezeleka ekushintsheni cishe ngo-10 μs.

Ukushintsha okusekela i-PTPv2 kubizwa ngokuthi amawashi Asobala ku-IEEE 1588v2 terminology. Amawashi abonisa ngale awavumelaniswa kusukela ewashini eliyinhloko futhi awahlanganyeli esigabeni esithi “Iwashi Eliyinhloko - Iwashi Lenceku”, kodwa lapho edlulisela imilayezo yokuvumelanisa akhumbula ukuthi umlayezo ubambezeleke isikhathi esingakanani yibona. Lokhu kukuvumela ukuthi ulungise ukubambezeleka kwesikhathi.

Amawashi angasebenza ngezindlela ezimbili:

• Ekupheleni-kuya-Ekupheleni.
• Ntanga-kuya-Ntanga.

Ukuphela-kuya-Ekupheleni (E2E)

Iwashi le-E2E elibonisa ngale lisakaza imiyalezo yokuvumelanisa kanye nemilayezo ehambisana ne-Landela_Up kuzo zonke izimbobo. Ngisho nalezo ezivinjwe ezinye izivumelwano (isibonelo, i-RSTP).

Iswishi ikhumbula isitembu sesikhathi lapho iphakethe le-Sync (Follow_Up) lamukelwe esikhumulweni nalapho lithunyelwa lisuka embobeni. Ngokusekelwe kulezi zitembu zesikhathi ezimbili, isikhathi esisithathayo ukuze iswishi icubungule umlayezo siyabalwa. Ngokwezinga, lesi sikhathi sibizwa ngokuthi isikhathi sokuhlala.

Isikhathi sokucubungula sengezwa endaweni yokulungisaInkundla yokuvumelanisa (iwashi elinesinyathelo esisodwa) noma umlayezo othi Landela_Up (izinyathelo ezimbili).

Iwashi le-E2E elibonisa ngale likala isikhathi sokucutshungulwa se-Sync kanye ne-Delay_Req imilayezo edlula ekushintsha. Kodwa kubalulekile ukuqonda ukuthi ukubambezeleka kwesikhathi phakathi kwewashi eliyinhloko kanye newashi lesigqila kubalwa kusetshenziswa indlela yokuphendula isicelo sokulibaziseka. Uma iwashi eliyinhloko lishintsha noma indlela esuka ewashi eliyinhloko iye ewashini lesigqila ishintsha, ukubambezeleka kuyakalwa futhi. Lokhu kwandisa isikhathi soshintsho uma kwenzeka izinguquko zenethiwekhi.

Iwashi elibonisa ngale le-P2P, ngaphezu kokulinganisa isikhathi esisithathayo ukuze iswishi icubungule umlayezo, ikala ukubambezeleka kwesixhumanisi sedatha esiya kumakhelwane wayo oseduze kusetshenziswa indlela yokubambezeleka komakhelwane.

Ukubambezeleka kukalwa kuzo zonke izixhumanisi kuzo zombili izinkomba, okuhlanganisa izixhumanisi ezivinjwe iphrothokholi ethile (njenge-RSTP). Lokhu kukuvumela ukuthi ubale ngokushesha ukubambezeleka okusha kumzila wokuvumelanisa uma iwashi le-grandmaster noma i-topology yenethiwekhi ishintsha.

Isikhathi sokucubungula umlayezo ngokushintsha nokubambezeleka kuyanqwabelana lapho kuthunyelwa imilayezo yokuvumelanisa noma ethi Landela_Up.

Izinhlobo zokusekelwa kwe-PTPv2 ngokushintsha

Ukushintsha kungasekela i-PTPv2:

• ngokohlelo;
• hardware.

Lapho usebenzisa iphrothokholi ye-PTPv2 kusofthiwe, iswishi icela isitembu sesikhathi ku-firmware. Inkinga ukuthi i-firmware isebenza ngomjikelezo, futhi kuzodingeka ulinde ize iqede umjikelezo wamanje, ithathe isicelo sokucutshungulwa futhi ikhiphe isitembu sesikhathi ngemva komjikelezo olandelayo. Lokhu kuzophinde kuthathe isikhathi, futhi sizothola ukubambezeleka, nakuba kungabalulekile njengangaphandle kokusekelwa kwesofthiwe ye-PTPv2.

Ukusekelwa kwehardware kuphela kwe-PTPv2 kukuvumela ukuthi ugcine ukunemba okudingekayo. Kulokhu, isitembu sesikhathi sikhishwa i-ASIC ekhethekile efakwe echwebeni.

Ifomethi yomlayezo

Yonke imilayezo ye-PTP inezinkambu ezilandelayo:

• Unhlokweni - amabhayithi angama-34.
• Umzimba – usayizi uncike ohlotsheni lomlayezo.
• Isijobelelo siyazikhethela.

Isihloko

Inkambu Yesihloko iyafana kuyo yonke imilayezo ye-PTP. Ubukhulu bayo buyi-34 bytes.

Ifomethi yenkambu kanhlokweni:

umyalezoType - iqukethe uhlobo lomlayezo odluliswayo, isibonelo Sync, Delay_Req, PDelay_Req, njll.

Ubude bomlayezo - iqukethe usayizi ogcwele womlayezo we-PTP, okuhlanganisa unhlokweni, umzimba nesijobelelo (kodwa ngaphandle kwamabhayithi okunamathisela).

domainNumber – inquma ukuthi umlayezo ungowasiphi isizinda se-PTP.

Isizinda - lawa amawashi amaningana ahlukene aqoqwe eqenjini elilodwa elinengqondo futhi avumelaniswa kusukela kuwashi eliyinhloko elilodwa, kodwa angavumelaniswa ngempela namawashi esizinda esihlukile.

amafulegi - Le nkambu iqukethe amafulegi ahlukahlukene ukuhlonza isimo somlayezo.

ukulungisaInkundla - iqukethe isikhathi sokulibaziseka kuma-nanoseconds. Isikhathi sokulibaziseka sihlanganisa ukubambezeleka lapho kuthunyelwa ngewashi elibonisa ngale, kanye nokubambezeleka lapho kudluliswa ngesiteshi uma kusetshenziswa Imodi Yontanga-kuya-Kontanga.

umthomboPortIdentity - le nkambu iqukethe ulwazi mayelana nokuthi lo mlayezo uthunyelwe usuka kuphi ekuqaleni.

ukulandelanaID – iqukethe inombolo kamazisi yemiyalezo ngayinye.

controlField – inkambu ye-artifact =) Ihlala isuka kunguqulo yokuqala yezinga futhi iqukethe ulwazi mayelana nohlobo lwalo mlayezo. Ifana kakhulu ne-MessageType, kodwa ngezinketho ezimbalwa.

logMessageIsikhathi – le nkambu inqunywa uhlobo lomlayezo.

umzimba

Njengoba kuxoxiwe ngenhla, kunezinhlobo eziningana zemiyalezo. Lezi zinhlobo zichazwe ngezansi:

Umlayezo wesimemezelo
Umlayezo wokumemezela usetshenziselwa “ukutshela” amanye amawashi ngaphakathi kwesizinda esifanayo mayelana namapharamitha awo. Lo mlayezo ukuvumela ukuthi umise isigaba sewashi lesigqila - Iwashi Eliyingcweti.


Vumelanisa umlayezo
Umlayezo Wokuvumelanisa uthunyelwa yiwashi eliyinhloko futhi uqukethe isikhathi sewashi elikhulu ngesikhathi kukhiqizwa umlayezo wokuvumelanisa. Uma iwashi eliyinhloko linezigaba ezimbili, khona-ke isitembu sesikhathi emlayezweni Wokuvumelanisa sizosethwa ukuze sithi 0, futhi isitembu sesikhathi samanje sizothunyelwa emyalezweni ohlobene othi Landela_Up. Umlayezo wokuvumelanisa usetshenziswa kuzo zombili izindlela zokulinganisa ukubambezeleka.

Umlayezo udluliswa kusetshenziswa i-Multicast. Ngokuzithandela ungasebenzisa i-Unicast.

Delay_Req umlayezo

Ifomethi yomlayezo we-Delay_Req iyafana nomlayezo wokuvumelanisa. Iwashi lesigqila lithumela i-Delay_Req. Iqukethe isikhathi i-Delay_Req eyathunyelwa ngaso iwashi lesigqila. Lo mlayezo usetshenziselwa kuphela indlela yokuphendula isicelo sokulibaziseka.

Umlayezo udluliswa kusetshenziswa i-Multicast. Ngokuzithandela ungasebenzisa i-Unicast.

Umlayezo_wokulandela

Umlayezo othi Landela_Up uthunyelwa ngokuzithandela iwashi eliyinhloko futhi uqukethe isikhathi sokuthumela Vumelanisa imilayezo inkosi. Amawashi ayinhloko anezigaba ezimbili kuphela athumela umlayezo othi Landela_Up.

Umlayezo othi Landela_Up usetshenziswa kuzo zombili izindlela zokulinganisa ukubambezeleka.

Umlayezo udluliswa kusetshenziswa i-Multicast. Ngokuzithandela ungasebenzisa i-Unicast.

Delay_Resp message

Umlayezo weDelay_Resp uthunyelwa iwashi eliyinhloko. Iqukethe isikhathi lapho i-Delay_Req yamukelwe iwashi eliyinhloko. Lo mlayezo usetshenziselwa kuphela indlela yokuphendula isicelo sokulibaziseka.

Umlayezo udluliswa kusetshenziswa i-Multicast. Ngokuzithandela ungasebenzisa i-Unicast.

Umlayezo we-Pdelay_Req

Umlayezo we-Pdelay_Req uthunyelwa idivayisi ecela ukubambezeleka. Iqukethe isikhathi umlayezo othunyelwe ngaso usuka echwebeni lale divayisi. I-Pdelay_Req isetshenziselwa kuphela indlela yokulinganisa ukubambezeleka kukamakhelwane.

Umlayezo we-Pdelay_Resp

Umlayezo we-Pdelay_Resp uthunyelwa idivayisi ethole isicelo sokulibaziseka. Iqukethe isikhathi lapho umlayezo we-Pdelay_Req utholwe khona yile divayisi. Umlayezo we-Pdelay_Resp usetshenziselwa kuphela indlela yokulinganisa ukubambezeleka kukamakhelwane.

Umlayezo we-Pdelay_Resp_Follow_Up

Umlayezo we-Pdelay_Resp_Follow_Up uthunyelwa ngokuzithandela idivayisi ethole isicelo sokulibaziseka. Iqukethe isikhathi lapho umlayezo we-Pdelay_Req utholwe khona yile divayisi. Umlayezo we-Pdelay_Resp_Follow_Up uthunyelwa kuphela amawashi ayinhloko anezigaba ezimbili.

Lo mlayezo ungase futhi usetshenziselwe isikhathi sokwenza esikhundleni sesitembu sesikhathi. Isikhathi sokwenza isikhathi kusukela ngesikhathi i-Pdelay-Req yamukelwe kuze kube yilapho kuthunyelwa i-Pdelay_Resp.

I-Pdelay_Resp_Follow_Up isetshenziselwa kuphela indlela yokulinganisa ukubambezeleka kukamakhelwane.

Imilayezo Yokuphatha

Imilayezo yokulawula ye-PTP iyadingeka ukuze kudluliswe ulwazi phakathi kwewashi elilodwa noma amaningi kanye nendawo yokulawula.

Dlulisela ku-LV

Umlayezo we-PTP ungadluliselwa emazingeni amabili:

• Inethiwekhi – njengengxenye yedatha ye-IP.
• Isiteshi – njengengxenye yohlaka lwe-Ethernet.

Ukudluliswa komlayezo we-PTP nge-UDP nge-IP nge-Ethernet

I-PTP phezu kwe-UDP nge-Ethernet

Amaphrofayli

I-PTP inamapharamitha amaningi aguquguqukayo adinga ukulungiswa. Ngokwesibonelo:

• Izinketho ze-BMCA.
• Indlela yokulinganisa ukubambezeleka.
• Izikhawu kanye namanani okuqala awo wonke amapharamitha alungisekayo, njll.

Futhi naphezu kweqiniso lokuthi sishilo ngaphambili ukuthi amadivayisi we-PTPv2 ayahambisana nomunye, lokhu akulona iqiniso. Amadivayisi kufanele abe nezilungiselelo ezifanayo ukuze axhumane.

Kungakho kukhona okuthiwa amaphrofayili e-PTPv2. Amaphrofayili amaqembu ezilungiselelo ezimisiwe kanye nemikhawulo yephrothokholi echaziwe ukuze ukuvumelanisa isikhathi kusetshenziswe kuhlelo lokusebenza oluthile.

Izinga le-IEEE 1588v2 ngokwalo lichaza iphrofayili eyodwa kuphela - "Iphrofayili ezenzakalelayo". Wonke amanye amaphrofayili adalwe futhi achazwe izinhlangano nezinhlangano ezahlukahlukene.

Isibonelo, Iphrofayela Yamandla, noma Iphrofayela Yamandla ye-PTPv2, idalwe yiKomidi Lokudlulisa Amasistimu Amandla kanye neKomidi Lesiteshi Esingaphansi Le-IEEE Power and Energy Society. Iphrofayili ngokwayo ibizwa nge-IEEE C37.238-2011.

Iphrofayili ichaza ukuthi i-PTP ingadluliselwa:

• Kuphela ngamanethiwekhi e-L2 (okungukuthi i-Ethernet, i-HSR, i-PRP, okungeyona i-IP).
• Imilayezo idluliselwa ngokusakaza kwe-Multicast kuphela.
• Indlela yokulinganisa ukubambezeleka kontanga isetshenziswa njengendlela yokulinganisa ukubambezeleka.

Isizinda esizenzakalelayo ngu-0, isizinda esinconyiwe ngu-93.

Ifilosofi yokuklama ngemuva kwe-C37.238-2011 yayiwukunciphisa inani lezici ozikhethela futhi kugcinwe kuphela imisebenzi edingekayo yokusebenzelana okuthembekile phakathi kwamadivayisi kanye nokwanda kokuqina kwesistimu.

Futhi, imvamisa yokudluliselwa komlayezo iyanqunywa:

Eqinisweni, ipharamitha eyodwa kuphela etholakalayo yokukhethwa - uhlobo lwewashi eliyinhloko (isiteji esisodwa noma ezimbili).

Ukunemba akufanele kube ngaphezu kwe-1 μs. Ngamanye amazwi, indlela eyodwa yokuvumelanisa ingaqukatha ubuningi bamawashi asobala ayi-15 noma amawashi emingcele amathathu.

Source: www.habr.com