Thỏa thuận mức độ dịch vụ SLA trên mạng NGN

Bai bao gidi thieu ve vai tro cua cam ket SLA thuat mi ca mb hinh kinh doanh, qiian li^, vatt hinh<br /> doi v6i viec cung cap djch vu viin thong thdi khai thic vi viee van dung mot each hieu qua, hpp<br /> gian tdi tren mang NGN, mot so khuyen nghi ly cua cac mb hinh db. Sue manh ciia canh ttanh niy<br /> vdi cac ben lien quan trong viec hu'dng den se duac the hien trade khach hing thbng qua kha<br /> trien khai cac cam ket SLA. nang cung cap dich vu vol eac cam ket chat lupng<br /> dich vu SLA.<br /> CHAT LL/QNG DICH VM - CHIA KHOA<br /> CANH TRANH TRONG CUNG CAP DICH VM SLA - RANG BUOC CO TINH PHAP LY<br /> V I I N THONG TL/QNG LAI GIQA CAC BEN VE CHAT LUgNG DICH vg<br /> Chat lupng dich vu (QoS) li chia khoi canh tranh Thoa thuan mtic do dieh vu SLA (Service Level<br /> trong linh vuc vien thbng toong lai, diy li cpiy luat Agreement): Li mdt thoa thuan hay hpp ddng dupc<br /> eb tinh to nhien. Trong qui khir siie manh eua canh ky ket giiia nhi cung cap san pham/dich vu (gpi tat li<br /> tranh thubng dua vio vimg phu, sir da dang eua dieh ben A) va ngubi mua san pham/su dung dich vu (gpi<br /> vu vi hien nay dang canh ttanh bang gii cube. Cie tit la ben B) ttong db ben A cam ket dam bao chat<br /> chieu thiic niy deu cb tinh ngin han vl dd ding dupc lupng san pham/dich vu cung cap cho ben B thong<br /> can bang giiia eie nhi eung cap do su phat trien cua qua rihiing thbng sd eu the. Ngoii ra, ttong SLA cbn<br /> cbng nghe, giam gii thirih thiet hi. Trong thbi gian ehi rb ttich nhiem ciia cie ben eb Uen quan, mire dp<br /> tbi, sir canh ttanh bing chat lupng dieh vu se di§n ra xu phat vi cic dieu khoan can thiet khic. Ban SLA li<br /> nhu li mbt he qua tat yeu. Canh ttarih bing QoS se van ban cb gii tti phip ly, eb the dupc ea hai ben su<br /> cb tinh liu dii vl chat lupng dieh vu li mpt yeu td the dung khi eb xay ra khieu nai hay khoi kien.<br /> hien tiem lire cua nhi khai thac; khbng ehi bang ky Cic cam ket SLA dupe xay dung tren ca sa cic yeu<br /> cau chinh ding eua khich hing. Trong quan<br /> he giiia ben mua vi ban thi ben mua mong<br /> mudn ben ban cam ket cing lihieu cing tdt,<br /> eic diem cu the ttong cam ket eb the rat lihieu<br /> vi tuy thupc loai hing hoa duge ttao ddi, toy<br /> nhien eb the phin lim hai loai: C3iat lupng ky<br /> thuat ciia ban thin san pham/dich vu vi chat<br /> lupng phuc vu. Chat lupng ky thuit duac the<br /> Hinh 1: SLA la hop dong giCra ben cung cap va tien sir dung hien qua kha nang dip img eua san pham<br /> theo ehire nang ciia nb (dp ben, dep, chinh<br /> <br /> <br /> 2 4 I TAP CHI CNTT&TT KY 1 (7.2010)<br />  CONG NGHE V I E N THONG<br /> <br /> <br /> Mang NGN la mbt mang da dich vu vbi cic dich vu<br /> <br /> ± OSA<br /> 3" party<br /> <br /> Ting irng<br /> phd bien hien nay li: VoIP, truy nhip Internet (HSI),<br /> truyen hliih tten IP (IPTV) vi Mobile. Kien tnic mang<br /> dnng<br /> Applications NGN da dugc dua ra ttong cic tii Ueu cua ITU, ETSI ve<br /> VoIP IPTV HSI Mobile ca ban gdm 2 tang ehirih li tang tmyen tai tao nen tii<br /> -VPiM- mang chuyen mach gbi IP vi tang dich vu/ung dung<br /> IP boardband Access &transport<br /> thue hien chire nang dieu khien logic cho cic loai<br /> •j~ User<br /> hinh dieh vu, img dung khic nhau (Hinh 2).<br /> <br /> Hinh 2: Mang va cac dich vu tren mang NGN<br /> Dam bao QoS End-to-End tten mang NGN li mot<br /> bii toan rat khb. Van de li phai lim sao cung cap<br /> xic...), chat lupng phue vu im ehi den cae van de Uen<br /> nhieu loai hinh dich vu cb khic nhau ve yeu eau<br /> quan den viec kinh doanh phuc vu (thbi gian cung<br /> chat lugng (QoS) tten cimg ha tang truyen tai IP vdn<br /> cap, su hb tta sau bin hing...). Cic cam ket niy can<br /> li mang Best-Effort. Su phuc tap ciia van de eb the<br /> duac bieu dien qua cic tham sd eb tinh dinh lupng<br /> rihin thay theo hai chieu: Theo chieu ngang, cac dich<br /> dugc gpi li SLS (Service Level Specifieation).<br /> vu tren mang NGN thubng di qua rihieu phan doan<br /> Die trung cua SLA li gii hing hoa tuong img vbi mang khie nhau, mdi phan doan nay cb each td<br /> chat lugng san pham, cimg loai san pham rihung chire, ebng nghe, ehinh sich su dung vi duge quan<br /> chat lugng cing eao thi gii cing eao vi nguge lai, ly bbi eae nhi eung cap khie nhau, van de QoS Uen<br /> die trung niy dam bao su tham gia ddng thai cua mang da de cap ttr rat sbm rihung den nay vin cbn<br /> lihieu lihi cung cap vbi Ibp chat lugng khie rihau. nhieu van de can giai quyet [7][8]... Xet theo chieu<br /> Trong thue te, sd Uen mi mdi khaeh hing sin sing dpe, mang NGN phin thinh cic Ibp (truyen tai, dieh<br /> bo ra de ehi eho mdi dich vu li khic nhau, se cb vu, img dung..), mdi nhi cung cap cb the chi tham<br /> nhiing khich hing sin sing tta gii cao de eb dugc gia mbt hoac mpt sd Ibp ttong db vi eie ca che quy<br /> chat lupng dich vu tdt nhat nhung ciing eb khich dinh ve dam bao QoS giiia cae lap ehua dugc dirih<br /> hing chi can mire chat lupng vira phai vbi miic gii nghia ro ring.<br /> hgp ly... khi phuc vu dugc cing nhieu Ibp ddi tugng<br /> Cac ddi tu'dng t h a m gia vao mo hinh cung<br /> khic nhau thi siic carih ttanh cua nhi cung cap se<br /> cap djch vu NGN<br /> cing Ibn manh.<br /> Mb hlrih kinh doaiih tten the he mang NGN cb su<br /> SLA eho ph6p cam ket ttong kha nang: Ky SLA phan Ibp chiic nang, cac ddi tupng khic nhau cb<br /> khbng cb nghia li eic nhi cung cap phai ky gidng<br /> the tham gia mbt (hoac mot sd) chire ning phii hgp<br /> nhau, chat lugng thue te li mot dai tuyen tinh vi eb<br /> vbi sd trubng vi nang lire ciia minh (Hlrih 3). Mpt sd<br /> the dugc phan lim lihieu muc, tuy kha nang cua nhi<br /> ddi tugng chinh ttong mb hinh li cac xP: Network<br /> cung cap dat dugc den mire nio thi se ky tbi miic db.<br /> provider (NP) li rihi cung cap ha tang mang. Service<br /> Mbi mire lai cb the eb ddi tupng phue vu khic rihau<br /> Provider (SP) li riha cung cap dieh vu nhu thoai,<br /> nen cie rihi eung cap khbng cb rihieu tiem lire eb<br /> mobile... AppUcation Service Provider (ASP) li nhi<br /> Uie nham vio cie ddi tugng thap hon (tatrihien,mire<br /> eung cap dieh vu img dung nhu Uitemet Banking...<br /> cam ket thap nhat phai cao hon cie chi tieu chat<br /> Content Provider (CP) li rihi eung cap npi dung vi<br /> lupng ban hirih bdi co quan quan ly)<br /> khach hing eudi (User). Ban thin cic xP vira nhi<br /> cung cap dich vu nhung eiing li khich hing ddi vbi<br /> SLA TREN MANG V I E N THONG NGN<br /> cac xP khic (vi du VoIP SP li khach hang eua NP).<br /> Mang NGN va van de QoS tren mang NGN<br /> <br /> <br /> <br /> TAP CHI CNTT&TT KY 1 ( 7 . 2 0 1 0 ) | 25<br />  CONG NGHE V I E N THONG<br /> <br /> <br /> <br /> lugng phuc vu bao gdm: Thdi gian cung<br /> cap dich vu cho khich hing, kha nang ho<br /> ttg, thbi gian xu 1^ su cd, ehinh sich hau<br /> mai... Cac tieu ehi dien hinh ve chat lugng<br /> ky thuat bao gdm: Ddi vbi ha tang mang<br /> truyen tai chung: Dp kha dung, tte gbi tin<br /> (Delay), bien dgng tte (Jitter), ti le mat gbi<br /> (Packet loss), miic dp an toin bao mat...<br /> ddi vbi cic dich vu/img dung lai cb eae<br /> Hinh 3: Cac ddi tupng chinh trong mo hinh cung cap djch vu NGN thbng sd bd sung mang tirih die trung cua<br /> dich vu nhu: Ty le thiiih cbng cube gpi,<br /> thbi gian thiet lap cube ggi, MOS... (dich<br /> vu thoai) hay chat lugng hinh anh, chat<br /> lupng am thanh, zapping time-thbi gian<br /> chuyen kenh (IPTV)... Bang 1 li vi du ve<br /> ^—{[—^ Sernce Pimider<br /> (SP)<br /> cic thbng sd SLA cho dieh vu VoIP vbi<br /> eic gibi han chat lugng da ban hinh bdi<br /> Bg TT&TT eiing nhu cua mbt sd td chire<br /> chuan hba.<br /> Hinh 4: Cam ket SLA co the co tai tat ca cac giao dien giua cac doi tupng<br /> SLA tten mang NGN da duge de cap<br /> SLA t r e n m a n g NGN mot cich he thdng trcng bg tii Ueu SLA<br /> Mang vien thbng NGN tiem an nhieu nguy ca ve management handbook eua TMF hay ITU-T E.860, d<br /> QoS, ehi can mbt xP ttong chudi cimg cap dich vu diy, SLA li mot bd phin chire ning ttong khung kien<br /> khbng dam bao QoS se anh hudng true tiep tbi khich tnic quan ly mang NGN (NGOSS) vi duge tieh hpp<br /> hing. chat che vbi bb quy trlnh nghiep vu hubng khich<br /> QoS li van de E2E nen dich den cua SLA ciing li hing (eTOM).<br /> tbi tan khaeh hing eudi, eie SP vi ASP thubng li nhi Nguyen t i c thifc hien giai phap SLA<br /> cung cap cb giao dien true tiep vbi khich hing eudi SLA li eie cam ket neu ttong ban hgp ddng giiia<br /> nhung ban thin SP khbng the ky khi hp ehua cb cam ben mua vi bin nhung de thuc hien eie cam ket niy<br /> kettiiNP, CP hay cie SP khie. Do viy, SLA khbng chi xP phai td chire thuc hien khi phire tap de dip img<br /> mdt bb phin nio db ttong chudi mit xich mi li van cie tieu chi SLA:<br /> de ttich lihiem ciia tat ca cic ben tham gia. - Ve eae tieu chl ky thuat Cac xP phai cb eg che/<br /> Cing cie nhi cung cap nim phia tten (vi du CP) giai phip ky thuat thiet lap, giim sit, duy tri, xu 1^<br /> eiia mb hinh cung cap dieh vu lal cing bi phu thupc phit sinh tii cam ket SLA (cic he thdng quan ly, he<br /> hon vio cic nhi cung cap nim phia ha tang dubi thdng monitor, he thdng dieu khien, he thdng bio<br /> (vi du NP); nhung cac quan he (CP, ASP, SP, NP) li cio, he thdng tirih cube, he thdng eaUeenter...) thbng<br /> quan he NxN, nen nb thiie day eic SP phai ning cao qua cae tham sd dinh lugng SLS (Hinh 5).<br /> chat lugng phan dieh vu eua minh de kbo duge khich Giai phap ky thuit eho SLA li mot van de vbi cac<br /> hing. xP do yeu eau dau tu khi Ibn vi nhieu khi eie tham<br /> Tren mang NGN, eic tieu chl SLA dien hinh ve chat sd SLS khie rihau cb the phai can giai phip ky thuat<br /> <br /> <br /> I 26 I TAP CHi CNTT&TT KY 1 (7.2010)<br />  CONG NGHE VIEN THONG<br /> <br /> Bang 1 : CSc th6ng so StJ\ cho djch vu VoP<br /> <br /> Yeu cau Tham so SLS Chi tieu tham khao<br /> <br /> D = Tong thoi lugng khach hing khong su dung dugc djch vu thupc >99.5%<br /> Do khi dung<br /> trach nhiem cua nha cung cap ' Tong thoi gian xac dinh dp kha dung (theo TCX 68-253)<br /> <br /> Thgi gian thiet lap dich vu sau khi ky hgp dong<br /> Tiiiet lap dich vu<br /> Tien dp thuc hien thiet lap dich vu (optional)<br /> Thay doi ve dia diem: cam ket ve thai gian Idiao sat, cam ket ve thoi<br /> gian thyc hien chuyen doi trong truang hgp du dieu kien...<br /> Thay doi dich vu<br /> Thay doi ve QoS: cam ket ve thoi gian khao sat, cam ket ve thai<br /> Chat<br /> gian thuc hien chuyen doi trong truang hgp du dieu kien...<br /> luong<br /> phuc Bao h6ng dich vu Thai gian khac phuc sy co (do khach hang thong bao)<br /> vu<br /> Tiep nhan khieu nai cua Idiach hang<br /> Khieu nai dich vu 48 gio<br /> Thai gian co van bin tr4 loi khieu nai cho 100% khach hang<br /> (theo TCN 68-253)<br /> Tinh cuoc dich vu Khi nang tra cuu cuoc thuan tien va chinh xac (optional)<br /> 24'7<br /> Tu van khach Thai gian nhan cong true<br /> (theo TCN 68-253)<br /> hang / Tiep nhan<br /> thong tin khach Ty le gpi toi djch vu ho trg. chiem mach thanh cong va nhan dugc > 80%<br /> hang tin hieu tra loi cua dien thoai vien trong vong 60 giay (theo TCN 68-253)<br /> <br /> Chiit luong am >3<br /> MOS<br /> thanh (theo TCN 68-253)<br /> <br /> < 150 ms<br /> Dp tre goi tin Dp tre<br /> (ITU-T: one-way)<br /> <br />