Efficient Building Method of Multiple Spanning Tree for QoS and Load Balancing

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1 Efficint Biding Mthod of Mti Snning Tr for QoS nd Lod Bncing yo Y, Shirshnk Ds, Yjin Lim, nd Mrio Gr Comtr Scinc Drtmnt Unirsity of Ciforni Los Angs Los Angs, CA hyoy, shnky, yjin, gr cscd Abstrct cnt trffic ftr is fr rmod from th trffic trnds sn dring th ry dys of Ethrnt tchnoogy Thrfor th crrnt IEEE stndrds nd its xtnsions to th Snning Tr rotoco f short of roiding stisfctory ity of sric for trffic hich hs significnt mont of QoS-snsiti trffic s s stbiizing th trffic od mong ho bridg ntork hr root sitch hs to hnd trffic from its chid sitchs In th crrnt nd nr-ftr scnrio of sitch ntorks ith significnty rg yr- cstrs nd nmros LANs, sho significnt shortcomings of th bsic Snning Tr nd th Mti Snning Tr rotocos ith rgrd to QoS nd od bncing In this r roos bridg ID schm of gion oot Idntifir hich is sd in Mti Snning Tr Instnc(MSTI) to roid th fficint biding mthod of MSTI for QoS nd od bncing Throgh this schm, th trffic sorc of PMP iction cn st itsf s th root of MSTI stisfying th QoS constrint hi roots of sr rgr MSTIs r bit in distribtd y W discss th robm in biding MSTI for PMP iction nd rgr MSTIs nd rsnt in dti or roosd schm Or xrimnts for to ross sho good imromnt of QoS in trms of dy nd od bncing of ho bridg ntork I INTODUCTION Ethrnt is th most common Intrnt nd ccss ntork Prios Ehtrnt is ntork shrd by hosts Bt nodys d to th rid domnt of tchnoogy, sch s siint Pckt ing (P), Ethrnt or MPLS (EoMPLS) [], nd Extndd Ethrnt i Stckd LAN tgging (EESLAN) in mtro r ntork (MAN), Ethrnt schm is or in th mtrooitn r In both ft nd hirrchic sitch ntork, thr is ot of rinc on th bsic oo fr Snning Tr Protoco for th corrct nd dsirb ortion of th ntork Th gcy IEEE D stndrd [] dots snning tr strctr to oid forrding oos, bcs oo in dt ink yr is mor critic thn in ntork yr This roch smd sib for th st f dcds or, rcnty mtimdi ictions h ttrctd ot of ttntion from th ntork commnity, nd rios dt tys ith diffrnt sric rirmnts h mrgd In this nironmnt, th gcy stndrd roch rying on sing snning tr brings bot th fooing robms First of, bcs th trffic is tnnd into th brnchs of th sing tr, ntork congstion tks c thogh bockd inks h nty of ib bndidth It brings bot th dgrdtion of sric ity for rsorc intnsi nd QoS(Qity of Sric)-snsiti fos Ths th or ntork bcoms ndrtiizd, nd th trffic nginring nd od bncing isss bcom ry diffict to b sod in sch conditions Scondy, th schding disciin in th gcy stndrd doys sim riority ing In this disciin, bcs th mtimdi trffic is rior to th non-mtimdi trffic, non-mtimdi fos of or riority my b strd by mtimdi fos of highr riority if mtimdi/highr riority fos r significnt frction of th trffic Finy mny th root of Snning Tr is st into high-ccity sitch to hnd trffic from ho bridg ntorks so tht of inks in th bridg ntork r not tiizd ny nd somtims th mfnction of root sitch css th dmg in th ho bridg ntork Athogh th IEEE s [3] nd othr docmnts nd rs [4] [5] trid to hnd ths robm, thy do not mntion QoS nd od bncing rtd robm In this r i rsnt th bridg ID schm sd in gion oot Idntifir in MSTI to roid th QoS in sorc-bsd snning tr for PMP iction nd od bncing in th ho bridg or sitch ntorks In sction i discss th s nd Q nd othr rs iming th fficint biding mthod for Snning Tr In sction 3 nd 4 rsnt or roosd schm for od bncing nd QoS for PMP iction Finy or xrimnts for to ross ith Qnt [6] r rsntd in sction 5 II MULTIPLE SPANNING TEE AND LAN A LAN [] ith MST is gro of nd sttions ith common st of rirmnts nd it sgmnts brodcst domin hich is th xtnt tht brodcst frm rogts throgh yr ntork, indndnt of hysic oction LANs h th sm ttribts s hysic LAN bt o to gro nd sttions n if thy r not octd hysicy on th sm LAN sgmnt To co ith th infficincy of th gcy IEEE stndrnds sr rochs, sch s STA(Snning Tr Atrnt oting) [4] rotoco nd Smrt Bridg [5] nd othrs [] [9] r rsntd STA dotd forrding grh in th c of forrding tr nd imrod th rformnc by sing th shortst th Bcs th QoS of fo cn b ffctd by th ngth of n nd-to-nd forrding th, this rotoco finds

2 nd forrds frms or trnt ths tht r roby shortr thn th gcy snning tr ths In ddition to STA rotoco Smrt Bridg combins th good ftrs of IP roting nd snning tr bridging hi rrnging to forrd ckts ong shortst grding mticst in sitch ntork, IGMP snooing [] nd othrs [] [] jst discssd th gro joining robm, not QoS trms or, in th bo rochs, th diffrnt tys of trffic in th sm gro r sti forrdd in th sm tr or th Ths th dgrdtion of sric ity nd strtion of o rioritizd fos sti rmin In cs of PMP ictions, Sorc-bsd snning trs r mor sitb thn th rndomy bt QoS stisfid MSTI for tht iction Bsids thm, sy th most of MSTI roots r octd in th high-cb sitchso if th roots of MSTIs r inrority or commony sctd for gnr trffic, th tiiztion of root inks r high nogh tht thr od b ot of frms dro hi it s iky tht thr r mor id inks hich r not sd in sr MSTIs To co ths to robms i rsnt th n schm for ssigning sion oot Idntifir of MSTI [3] dfins th nottion of ni bridg ID to rnt th confict or dciding root of th snning tr nd to ssign root of tht in scific y Among octts of MSTI gion oot Idntifir(I) s dfind in [3] nd [], th 4 MSB bits r mngb Or n schm for ths bits is to xtnd ths fids in mor bits, diid thm nd gi th biity of nnb-root nd th distribtd root of sr MSTIs III DISTIBUTED OOTS OF MULTIPLE SPANNING TEE In this sction, bfor xining th sg of scond fid of or n I h to kno bot th riority ctor hich is sd to choos th root ort of gin sitch hich gts n BPDU from its nighbor In th MST Priority ctor cction dfind in [3], ort ith ort riority ctor for MSTI consisting of,,!#" $ %&', () ' ", nd *,+) " comrs th rciing BPDU, mssg riority ctor ith its on riority ctor ccording to comrison r Th comrison r is tht if th first comrison of th first fid mks ti th dcision jms to th scond fid nd so on Th scond MSB rt of I is sd to mk sitch h ss roots of MSTIs by msring th orts stts t rgr tim As ncssry condition for sitch to bcom root of tht MSTI, th stts of orts h to b st to dsigntd ort Athogh th inrorit msrmnt t rgr tim, sch s th sm crtion tim of sr MSTIs hn ch sitch tris to bcom root ith sm nmbr of th scond MSB in I, gis th rong informtion, somtims tr hn th rios MSTI bcoms stb nd sitchs kno thir ni root of tht MST Thrfor hn n rst of MSTI coms, it s iky tht root sitch h ss chnc to bcom root of nxt MSTI bcs th scond fid of I hs mor tht th othr sitchs So th scond fid of I is rrsy roortion to th robbiity of bcoming root of nxt MSTI rst I SOUCE-BASED SPANNING TEE FO PMP APPLICATIONS A Msticst in sitch ntork Trditiony, IP ckts r trnsmittd in on of to ys, nicst or brodcst IGMP (Intrnt Gro Mticst Protoco) is sssion-yr rotoco sd to stbish mmbrshi ith mticst-nb rotr in mticst gro In this sittion th big robm is tht mticst trffic is trtd in th sm mnnr s brodcst trffic so tht it is forrdd to orts To hnd this robm in bridgd ntork, thr r sr sotions, sch s IGMP Snooing [], CGMP(Cisco Gro Mticst Protoco) [], GMP(GAP Mticst gistrtion Protoco) [] Bt sti ths mticst ckts r dird in th gin snning tr Frthrmor for LANbsd mticst trffic, MSTI hs to b formd in dynmic y stisfying th QoS rirmnt from th iction sssion Whi thr h bn sr rs [] [], thy did not considr mticst trffic in condction ith MSTI for tht LAN B Sorc-bsd Snning Tr Bsids sr mticst rotings for mticst tr in IP ntork, sch s Sorc-Scific Tr, Shrd Distribtion Tr, Cor-Bsd Trs, nd tc, in th bridgd ntork MSTI is ndd for tht scific trffic s s th oo fr to rnt brodcst In this i, sorc-bsd snning tr cn b siy sd for PMP trffic hi stisfying th QoS ith th xisting BPDU Fig Dth # of sitchs N + (A) N +N oot sitch sitch A //////// //////// N-ry comt tr for Sorc-bsd MSTI Sos tht QoS stisfying MSTI ith n-ry comt tr is gin nd sorc of PMP is octd t th root of MSTI s shon in Fig Frthrmor ssm tht in this MSTI th QoS contrint for PMP is dy nd ch ink hs on nit dy Aso t ch bridg thr r dstintion hosts connctd to tht In this n-ry comt tr, th th cost t ch yr from th root sitch is hr 45 is th nmbr of sitchs t dth Thrfor th smmtion th cost to ch nods from root sitch is 9;:< 5%=> 9 () hr D is th dth of th tr No th sorc host of PMP mos to sitch A In this sittion, th th cost to ch sitchs hich bong to this sitch A rdcs by hi th th cost to othr

3 E 3 sitchs hich bong to th origin root sitch incrss by Usy th nmbr of sitchs in sbtr of comt tr is ss thn tht of sitchs of othr sr sbtrs W cn rit don this rocdr of th cost chng s fooing Bfor th sorc host mos, th tot th cost to ch sitch from th root sitch is?a BDC FE G = BI #G = BKJMLN O = BIP QO = BKJMLN P ===, 9;:< 5= B 9 9S: C 5= BKJMLN 9UT No ftr th sorc trffic of PMP mos into sitch A th tot th cost to ch sitch from sitch A is E G = BDC? O = BI BKJLN W = BXP #G = BKJMLN P ===Y 5 FE = B 9 9S:%<[ 9S: C 5%] E = BKJMLN 9UT ^ 5 hr ^#5 is th nmbr of sitchs not bonging to sitch A t dth i nd ;_ is th nmbr of sitch bonging to sitch A t dth i So th diffrnc btn ftr-moing nd bfor-moing bcoms hr ^ t dth ;_ B C B ] B JMLN B P ] BKJLN P ===, 9S: C B 9 ] BKJLN 9 T `b bcs th nmbr of chidrn of A is zro Usy th ^F5 is grtr thn ^ 5;_ t ch dth of n-ry tr so tht th diffrnc in (4) is gtting rg ositi s th D bcoms rg in th comt tr This mns tht if th trffic sorc of PMP is t into sitch hich is th root of sm siz sbtr, th or diffrnc in trms of th cost to ch sitch, sch s dy, bcoms rg Thrfor rthr thn tting th sorc trffic t on osition of MSTI rndomy bit, it s bttr to bid MSTI s sorcbsd tr for tht trffic hi stisfying QoS ctiy W xind tht gnr cs in Adix To s sorc-bsd tr for PMP fficinty ith STP BPDU, h to think or th dfinition of % '" )c" d dfind in [3] hich cts s th dynmic mtric dring MSTI biding Originy this is cctd in th smmtion of rootcost of ch ort tord root of MSTI Bt for sorc-bsd tr this dos not mk sns bcs nd donrd cost, not rd cost to th root of MSTI In th rcnt sitch most of inks r id ith dx cbiity so tht th cost of ink in MSTI shod b th donrd cost to ch chid sitchs, not th rd cost To s donrd cost h to modify th rocdrs, dtosmsti nd txmst hich r dfind in [3] Th fnction txmst trnsmits n MSTI Configrtion Mssg, ncodd nd ttchd ith MST BPDU ccording to th scifiction of [3] Among its comonnts, MSTI intrn () (3) (4) oot Pth Cost shod b ddd ith th cost of th snding ort In cs of dtosmsti, hi dciding th root ort in ch sitch, it dos not h to dd th cost of ch ort bcs th rcid BPDU rdy contins th cost of donrd from its nighbors SIMULATION ESULT To t th rformnc of or n mchnism, dotd th Qnt 35 ntork simtor [6] hich crrnty hs ony th IEEE D [] nd Q [] mods for snning tr nd LAN mchnism W immntd th IEEE s for MST nd or bridg ID schm in MST mods, nd comrd th rformnc btn both of thm in trms of th ink tiiztion nd nd-to-nd dy A Distribtd oots for MSTI As shon in Fig hr sitch is cntrd, sitchs r connctd to ch othr hi sitch hs mor ink ccity to ct s root of sr MSTIs In rgr sittion, d to th origin bridg ID schm sitch cts s root of ho MSTs Bt ith or schm, ch MST rst is distribtd mong sitchs so tht th trffic r distribtd mong nsd inks, sch s ink btn sitch nd 4 Bockd ink Acti ink Sitch Sitch 4 Sitch 6 Sitch Sitch Sitch 3 Sitch 5 Fig sitchs ntork cntrd t sitch Fig3 shos th ink tiiztion of ch sitch by orts of tht dring simtion W sd th sm nmbr of trffic ith rios sr trffic tys s dfind [] In cs of On oot, ony on ort of sitch is sd to snd frms to root of its MSTI hi in cs of Distribtd oot, ib orts r sd t th sm tim Aftr simtion, cctd th rg ink tiiztion nd dition for both css ith sm trffic mont TbI shos th diffrnt s sying tht Distribtd oot cs hs ss of rg nd dition of ink tiiztion This mns tht Distribtd oot schm gis mch ss sg of ink s s mor stb trffic od mong ho sitch ntork Frthrmor if mor inks r id, th diffrnc i gt rgr Finy rn xrimnt to ro or bridg ID schm hthr it orks in or Qnt mod in x grid sitch tooogy corrcty Fig4 shos tht in both css, rgr S rri of MSTI rst nd rndom rri, ch sitch trid to t its bridg ID s th crrnt nmbr of roots s itsf nd bit MSTI bsd on this In cs of rgr rri ch sitch shrs th MSTI roots ny from sm of sitch indx to rg In th rndom cs, n if ch sitch st th bridg ID bsd on th crrnt th diffrnc of ch sitch is not big so tht or MSTI rsts r distribd mong ho sitchs

4 4 5 4 Link Link Utiiztion of sitch by I/F Link Link Utiiztion of sitch by I/F Stisfying ink 5 [] [] 6 4 [] [] [3] [4] [5] [6] [] 6 4 [3] [4] [5] [6] [] () On oot (b) Distribtd oot Unstisfying ink 9 Fig 3 Link tiiztion of to scnrios Fig 5 Grid Tooogy for sorc-bsd snning tr Nmbr of root in tot MST 49 Nmbr of root in tot MST x -3 MCB Srr Arg End-to-End Dy (s) x - MCB Srr Arg End-to-End Dy (s) NodID NodID Fig 4 Nmbr of roots in ch sitch in On oot s Distribtd oot () sitch is root (b) sitch 9 is oot B Sorc-bsd Snning Tr for PMP In this xrimnt sd PMP iction in th sdo grid tooogy s shon in Fig5 W st th stisfying ink ms dy nd th nstisfying ink ms dy so tht th or MSTI cn b bit ony ith th dsird stisfying inks Aftr stting th dy in ch ink, t 9 hosts hich ct s th dstintion of th PMP iction, thn th sorc host is schdd to b t t sr sitch ositions throgh 9 Fig6 shos th rst of to css of sorc host osition hr sitch, th root of MSTI nd sitch 9, f of MSTI r th osition of sorc host rctiy In cs of sitch, th dy incrss s th dstintion hosts r fr from th root Bt in cs of sitch 9, s xcts th s of sbtr roots, sitch 5 nd 3, ying in th th from sitch 9 to sitch h th ongst dy s No mk css of ossib ositions of sorc host mong sitchs Fig shos th rst got sing th tooogy of Fig5 Fig () sys th rg dy to dstintions hn th sorc host is t t ch sitch osition hi (b) sys th smmtion of dy to dstintions In th Fig 6 Ag End-to-End dy in to diffrnt roots Fig th css of sm dth osition of sorc host gi th sm togthr for rg dy nd dy smmtion This figr ros tht s th sorc host is t fr y from th root of MSTI th dy to dstintions is gtting incrsd s dscribd in th (4) smmtion of dy to ch dstintion hosts sitch ID g-dy () Arg dy of ch root Fig Ag nd Smmtion of End-to-End dy smmtion of dy to ch dstintion hosts sitch ID sm-dy (b) Dy sm of ch root On oot Distribtd oot Ag 5 4 f 5 TABLE I AG AND f OF LINK UNTILIATION I CONCLUSION AND FUTUE WOK Originy Snning Tr bridgs dfind in IEEE stndrds h sr good ftrs, sch s sf-configring, trnsrncy to hosts, nd indndncy to th ntork rotoco Unfortnty this Snning Tr schm hs disdntgs so tht this hs bn rcdd from bing mor idy doyd In this r h shon th fficint bridg ID schm iming th QoS for PMP nd od bncing of ho sitch ntork For od bncing sd n bridg ID by msring th stts of orts to mk it sr tht th sitch is th root of MSTI Athogh this msrmnt dos not grnt tht th sitch i b th root of crrnt MSTI, somtims tr hn thr is nothr rst of MSTI,

5 T G G G ] T 5 this sitch ts th corrct of roots nmbr so tht it i not b th root of th nxt MSTI rst For QoS of PMP, h shon tht th sorc-bsd snning tr gi bttr rformnc hn th sorc host is t t th root of Snning Tr hich is stisfid ith QoS contrint Crrnty h gmntd th Qnt simtor [6] for MSTI nd immntd or schm in tht As nxt ork, h to tiiz this schm for mticst iction, sciy PMP in sitch ntork To stisfy th QoS rirmnt in MSTI nd mor sohistict QoS schm in sith ntork W r ning to immnt or schm in Qmtor [3] FE = B3C QGA = B ] E = B J N ] GA = BX QG ] E = BKJ N === QG = B?Y FE = B ts)c ] E = B tsc === QO = B $s)c B ts)c C = B ] E = ByJ N === = ByJ C N 5 = B 9 9;:<[ : C ] G = BKJ N === : ] 5 = B 9 9;:<[ 9S: C ] G 5 = BKJ [x 9 s)c N [:%9 = BKJ C N (6) APPENDIX A Th tot cost chng of Gnr Moing W i discss th cost chng for gnr moing of sorc host in Snning tr Sos tht root of sitch jms into th dth nd th sitchs from th origin root to th sitch r indx g throgh from th sitch to root s shon in Fig Dth nmbr of sitchs N + oot sitch I st mo sitch I Finy th diffrnc btn ftr-moing nd bformoing of gnn cs is 9;: C B 9 9;: C [:%9 ] G 5 = BKJ x 9 sc N () hr ^ ;z `{ if is th sm ith th sitch ID of th th dth Th first trm of ( ) is ys ositi nd so is th scond Usy th nmbr of chidrn of srtr root is mch grtr thn tht of sbtr root So th smmtion hn rchs to )}%~ is grtr thn th smmtion hn is t th rng of &} nd Thrfor or diffrnc bcoms ositi Fig k D (I) (j+) N +N + +N + k k k jjjjjjjj jjjjjjjj kkkkkkk hhhhhh iiiii D D kkkkkkk hhhhhh iiiii mmm nnn ooo (I) () N +N + +N D Gn cs of N-ry comt tr sitch j sitch In th origin cs th smmtion of cost to ch sitch is?y B3C FE G = BX QG = B QGA = BX = BKJ N === === B re = BItsC FE = B ts)c J N === = B = B J N === 5= B 9 9;:< : C' = B J N 5= B 9 9;:< 9;: C = B J C N === :9 = B J [x 9 s)c N [: % = B J C N FE = B J C N $s)c (5) EFEENCES [] L Mrtini, t, Trnsort of Lyr Frms Or MPLS, IETF Intrnt Drft, drft-mrtini-circit-trns-ms-txt,no [] IEEE D, Stndrd for oc nd mtrooitn r ntorks: mdi ccss contro (MAC) bridgs, 99 [3] IEEE S/D5, Drft stndrd for oc nd mtrooitn r ntorks: mndmnt 3 to Q irt bridgd oc r ntorks: mti snning trs, [4] K S Li, W C L, nd K Nhrstdt STA: trnsort snning tr bridg rotoco ith trnt roting ACM SIGCOMM Comtr Commnictions i, o3(3), -46, Jy [5] T L odhffr, C A Thkkth, nd D C Andrson SmrtBridg: A Scb Bridg Architctr ACM SIGCOMM Comtr Commniction i Agst om 3 Iss 4 [6] Scb Ntork Tchnoogis (SNT) htt://scbntorkscom [] IEEE Q, Stndrd for oc nd mtrooitn r ntorks: irt bridgd oc r ntorks, 99 [] omn Grci, Jos Dto nd Jn Jos Srrno, A N Trnsrnt Bridg Protoco for LAN Intrntorking Using Tooogis ith Acti Loos [9] T Aj J-Ch Grgoir, Admission Contro nd Bndidth Mngmnt for LANs [] J Wng, L SUn, X Jing, nd W IGMP Snooing: A LAN- Bsd Mticst Protoco [] CISCO SYSTEMS Cisco Gro Mngmnt Protoco htt://ciscocom [] Scn oony, Christin ortng, nd Jns Krs Atomtic LAN crtion bsd on on-in msrmnt, ACM SIGCOMM Comtr Commniction i [3] Qmtor htt://cbrntcscd/ shnky/mtor/ Bt ftr jming into sitch g, th chngd smmtion of th cost bcoms