Wise<TE/VPN>: Traffic Engineering & VPN Manager for A Large-scale MPLS-based IP Network

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1 Wise<TE/PN>: Traffic Egieerig & PN Maager for A Large-scale MPLS-based IP Network TS Choi, SH Yoo, HS Chug, CH Kim, JS Park, BJ Lee, TS Jeog Iteret Architecture Team, ETRI {choits, shpyoo, chughs, kimch, jspark, bjlee, tsjeog@etri.re.kr} Abstract As the Iteret is quickly evolvig from best-effort etworks to a very critical commuicatios ifrastructure that requires higher quality Iteret services ad the delivery of such commuicatios services become competitive, large-scale NSPs or ISPs have to cocer much more o the performace ad efficiet resource usages of their etworks. This situatio aturally leads the providers to seek a possible solutio from traffic egieerig (TE) methodologies. Also MPLS PN ca take advatage of TE for more reliable ad efficiet usage of the maaged etwork resources. I this paper, we propose a itegrated TE ad PN maagemet solutio for a large-scale MPLS-based IP autoomous system, which addresses TE ad PN maagemet requiremets such as the auto-provisioig, measuremet, characterizatio, modelig ad cotrol of Iteret traffic.. Itroductio As the Iteret is quickly evolvig from best-effort etworks to a very critical commuicatios ifrastructure that requires higher quality Iteret services ad the delivery of such commuicatios services become competitive, large-scale NSPs or ISPs have to cocer much more o the performace ad efficiet resource usages of their etworks. This situatio aturally leads the providers to seek a possible solutio from traffic egieerig (TE) methodologies. Although TE has bee a part of the everyday etwork operatios for large-scale NSPs ad ISPs, they have bee depedig o legacy TE mechaisms such as IGP metric-based TE ad overlay etwork approach. The former ca solve parts of the TE problems but has some drawbacks such as Blame Shiftig problem, lacks of graularity ad istability. By chagig OSPF or ISIS cost metrics, a cogested flow ca be moved ito a ewly calculated path. But this shifts the problem ito the ew path istead of solvig the fudametal cogestio problem. Also this solutio does t provide global optimizatio ad, thus, causes istability agai. The latter was used quite ofte for ATM ad frame relay etworks but has problems such as full mesh overhead, cell tax ad lack of itegratio. Besides the abovemetioed drawbacks, traditioal TE solutios lack the capability to meet ed-users service quality requiremets. MPLS was itroduced to address these shortcomigs ad to provide predictable, reliable ad efficiet TE solutio []. Mechaisms such as Label-based packet forwardig, costrait-based explicit path selectio ad sigalig are supposed to solve the problems. Practically speakig, however, the existig MPLS implemetatios exposed a umber of issues to be resolved. Almost everythig but sigalig stadard might be differet ad the obvious result may be upredictable operatios whe more tha two heterogeeous products are used i a etwork domai. Olie path calculatio cosiders oly oe LSP at a time ad causes lack of global optimizatio. Also, sice there is o stadard way of defiig a traffic truk, it gives aother burde to etwork admiistrators to come up with its ow policy. Fially, the traffic measuremet, aalysis ad cofiguratio maagemet is purely left up to the service providers. Accordig to [2], Iteret TE is defied as that aspect of Iteret etwork egieerig dealig with the issue of performace evaluatio ad performace optimizatio of operatioal IP etworks. It ecompasses the applicatio of techology ad scietific priciples to the measuremet, characterizatio, modelig ad cotrol of Iteret traffic. Most of MPLS/BGP PNs curretly deployed deped o LDP-based traffic forwardig. This forbids the operators from takig full advatage of MPLS-TE capabilities for PN traffic. MPLS-TE ad PN is a atural itegratio to provide better quality PN service to customers ad efficiet ad reliable usage of the maaged etwork resources. I this paper, we propose a itegrated TE ad PN maagemet

2 solutio, Wise<TE/PN>, for a large-scale MPLSbased IP autoomous system, which addresses these requiremets. Eve though TE is the most effective whe applied ed to ed, our iitial objective is for itra-domai ad iter-domai issues are left for our future work. Some of the core fuctioality i the server is described below. Wise<TE/PN> stads for Traffic Egieerig ad PN maager for wise Iteret service egieerig. LSP/PN Cofiguratio Maagemet ad Quasirealtime Moitorig Wise<TE/PN> ca provide uified ad cosistet cofiguratio paels for LSP ad PN maagemet, eve if the target etwork is comprised of heterogeeous routers ad switches. Cofiguratio paels are desiged to be simple ad ituitive, fully compatible with related RFCs, ad various router OSes. Cofigured ad eforced LSPs are moitored by quasi-realtime based pollig or otificatio mechaisms by COPS [3], SNMP [4], or router-specific CLI, ad those results are logged ad iformed to etwork admiistrators via GUI. ersatile iews of IP, MPLS, Routig (OSPF ad BGP) ad PN Topology Not oly a topological view of IP layer, MPLS ad routig protocol specific views are essetial for etwork admiistrators to efficietly uderstad ad respod to etwork ad routig behaviors. For the sake of user s requiremets, MPLS views cotai several sub-views such as a badwidth allocatio view, a LSP traffic statistics based lik utilizatio view, a lik affiity view, ad a forwardig adjacecy LSP view. Aother importat fuctio of Wise<TE/PN> is to reder a view of global routig topology ad routig behaviors. Such views ca maifest how those protocols are cofigured, ad alog which paths flows are routed. Sice OSPF lik-state database ad BGP path attributes are also aalyzed, etwork admiistrators ca diagose a suspicious routig behaviors resulted from a miscofiguratio. TE/PN Policy Maagemet Network admiistrators ca easily edit, modify, save, eforce, schedule, ad withdraw various policies for maagig MPLS TE/PN. Durig such processes, illogical policy coflicts are automatically detected ad resolved by the server. IP Traffic Measuremet ad Aalysis for MPLS Wise<TE/PN> provides traffic measuremet ad aalysis capability for LSPs ad PN traffic i a quasi-realtime basis, so that etwork admiistrators ca easily detect ad diagose LSP ad lik utilizatio, cogestio, etc. Besides, whe routers support flow-based traffic samplig fuctios, Wise<TE/PN> ca measure ad aalyze per-flow traffic statistics which play a very importat role for uderstadig the tred of traffic demad betwee routers, subets, adjacet ASes ad PN customers. Itelliget Path Computatio, Recommedatio, ad arious Simulatios Sice Wise<TE/PN> possesses the same Costrait-based Shortest First (CSPF) algorithm [5], which is beig used by most MPLS routers ad switches, it ca precompute a path for a give LSP ad check its availability before, the LSP is eve eforced to a etwork. Utilizig this mechaism i cojuctio with measured traffic demad ad LSP statistics, Wise<TE/PN> ca simulate lik/ode failures, ad global optimizatio. This paper is orgaized as follows. Sectio 2 provides a overview of the server architecture ad desig priciples, requiremets ad decisios. Sectio 3 describes subsystem details o their architectures ad fuctioality. Our implemetatio experieces are oted i Sectio 4. Fially, we coclude the work ad itemize some of importat future research issues. 2. System Architecture ad Desig 2.. Overall System Architecture Figure shows a high-level view of Wise<TE/PN> architecture. The brief fuctioality descriptio of each fuctioal block is give below. The fuctioal details will be explaied i Sectio 3. TMS DB Traffic Measuremet Results Measured Traffic Data GUI TMS SNMP CSI (Commo Service Iterfaces) RMS DB SNMP Pollig Results Cofiguratio Package Global Cofig Package TMS Aget Cisco CLI CISCO Router RMS RMS Aget Juoscript Cliet Juiper Router Measuremet Package Misc Package COPS Aget ACE CLI ACE2000 COPS RATE Figure : Overall architecture of Wise<TE/PN> PS PS DB Proxy Aget PIB OSPF/BGP

3 Wise<TE/PN> cosists of a Commo Service Iterface (CSI), a GUI, a policy Server (PS), a resource moitorig server (RMS), a traffic measuremet & aalysis server (TMS), a routig advisor for traffic egieerig (RATE) ad a proxy aget. CSI is service iterfaces commo to all servers. Its fuctioality icludes global cofiguratios, MPLS TE/PN specific cofiguratios, topology maagemet ad traffic measuremet & aalysis. These commo fuctioalities are desiged as IDL [6] iterfaces to make the system scalable, extesible ad iteroperable with other related systems like etwork maagemet systems (NMSs). Desig details are described i the sectio 2.2. PS follows the architecture defied by IETF s policy framework workig group. [7] It hadles etwork-wide MPLS TE/PN policy decisios, policy rule coflict resolutio ad admissio cotrol for MPLS etworks. It uses COPS protocol to trasmit MPLS TE/PN policy ad resource iformatio to/from a proxy aget or COPS-eabled etwork devices. It automates complex MPLS TE/PN cofiguratio processes across the etire maaged etwork domai. Network resource ad traffic data are gathered ad processed by two servers. RMS collects etwork resource iformatio such as iterface statistics, topology data ad LSP cofiguratio iformatio. TMS gathers traffic measuremet data such as adjacet AS traffic matrix & prefix traffic matrix ad aalyzes them. They are stored i RMS & TMS DB respectively for further processig by other servers. RATE performs simulatio tasks based o the moitored, measured ad aalyzed data. Simulatios supported are LSP path availability check, LSP path modificatio result aalysis, failure sceario ad global optimizatio. Also commuicatio betwee subsystems utilizes iteratioal ad de facto stadard protocols such as COPS, SNMP,, LDAP [8] ad SQL to facilitate iteroperability. Itegratio of these fuctioality eables Wise<TE/PN> to automate policy-based MPLS TE/PN cofiguratios icludig traffic truk idetificatio ad correspodig LSPs provisioig ad mappig from a traffic truk to a PN, to moitor, measure ad aalyze etwork ad traffic behavior, to maitai optimized etwork operatios ad to provide aalyzed data for future capacity plaig Desig Priciples, Requiremets ad Decisios The mai desig priciple of Wise<TE/PN> is object-orietatio. With this priciple, we ca make our system more scalable, extesible, ad iteroperable. Give a target maaged etwork, appropriate object classes ad their relatioship modelig ad object istace maagemet provide system scalability. System compoets ca be added without modificatio of the existig system. It also allows smoother itegratio with other maagemet systems due to the priciple of objectorietatio. NodeMaager IpNodeMClassf IpNodeCClassf 0.. MplsNodeMClassf MplsNodeCClassf serves pmaager pm DsNodeMClassf Node OspfNodeClassf DsNodeCClassf TtMaager TtM BgpNodeClassf 0.. IpIfMClassf serves IpIfCClassf MplsIfMClassf LspTuelMaager IpIfMClassf Figure 2: Object Model for Commo Service Iterfaces Figure 2 illustrates a part of CSI iterfaces for maagig MPLS topology ad measuremet data. It shows required object classes ad their relatioships. All classes specified with a capital letter C serve for cofiguratio purpose ad oes with a letter M serve for measuremet. TtM ad LspM implemet iterfaces to set ad retrieve respective measuremet data. For example, LspM class has methods to get LSP statistics of daily, weekly, mothly or yearly basis. Node ad Iterface classes iclude associated classificatios classes based o its type. Node ca be a IP ode, a MPLS ode, a OSPF ode or a BGP ode. Similarly, a iterface ca be a IP iterface, a MPLS iterface, ad so o. Although a ode or a iterface ca be physically the same oe, it serves differet fuctios logically depedig o situatios. Life cycle of each object is maaged by its correspodig maager class. Servers ca commuicate with these maager classes for the maagemet of objects of iterests such as creatio, modificatio, deletio, searchig for a particular object, etc. By modelig MPLS cofiguratio ad measuremet fuctioality ito commo iterfaces, all servers i Wise<TE/PN> ca access the Iterface MplsIfSClassf DsIfMClassf MplsIfCClassf Lsp Tuel BgpIfClassf DsIfCClassf OspfIfClassf LspM SPath 2.. Iterface MplsIfMClassf

4 ecessary iformatio if required. This allows our system more scalable ad extesible. Our desig eables represetatio of various topological views such as IP, MPLS, OSPF ad BGP. It ca also represet measured statistics data over each topology. For example, IP lik statistics, MPLS LSP statistics ca be captured over correspodig logical topologies. This desig approach allows Wise<TE/PN> to be easily exteded to add additioal fuctioality such as TE for optical etworks. Besides CSI, all other subsystems are also desiged based o object-orietatio priciple. They are realized usig techology. 3. Sub-system Architecture ad Fuctioality 3.. Policy Server CSI CSI/ Other PS or NMS PDM Mgmt. Module Target Mgmt. Module Coflict Detectio Module GUI Policy Processig Module Admissio Cotrol Module DB Cliet API Format Coversio Module COPS Server Module Policy Maager LDAP Cliet API Policy Decisio Module LDAP Cliet API COPS Policy Target (COPS-eabled or Proxy) LDAP/SQL Figure 3: PS Architecture Policy Repository LDAP server Local PIB DB Back- Ed DB Policy server cosists of a policy maager (PM), a policy decisio module (PDM) ad a policy repository (PR). Figure 3 shows details of each sub modules. PM iteracts with GUI, other PS or Network Maagemet System (NMS) ad PR. It receives a policy rule, checks validity ad stores i the repository. PDM further ecodes it ito a COPS message ad trasfers it ito the appropriate policy targets ad processes ay feedback evets. The details are described as follows. PDM Maagemet Module: To hadle complex policy domai, each policy domai ca be divided ito a umber of groups. Each group is maaged by a PDM. Whe there are more tha oe PDM, this module maitais iformatio o each PDM ad fids appropriate PDM whe a policy eeds to be eforced. Coflict Detectio Module: Before a policy is eforced, coflict(s) should be checked agaist the existig oes. A policy rule is composed of coditios ad actios. This module checks the requested policy s coditios ad verifies that ay actios coflict with the existig oes. There are two types of policy coflicts: oe with reflectig the curret etwork state (e.g., available badwidth, utilizatio, etc) ad oe without reflectig it. The coflict checks for the latter ca be performed relatively easily but oes for the former ivolve admissio cotrol decisios ad other optimizatio issues. This module works closely with the admissio cotrol module whe a admissio cotrol decisio is required. Admissio Cotrol Module: A policy rule ca t be eforced without uderstadig uderlyig etwork resource availability. This module checks resource status ad returs a admissio decisio for the requested policy rule with the help of etwork moitorig, measuremet ad aalysis fuctioal blocks. [9] Target Maagemet Module: Oe PDM maages oe or multiple policy targets. It maitais a umber of coected policy targets ito groups. This requiremet is essetial to provide scalability i maagig a large-scale etwork, which typically cosists of more tha several hudreds of routers. We solve this problem by thread based module desig Policy Processig Module: Whe a ew policy rule is created or a existig rule is modified, this module maages its eforcemet schedule. DB ad LDAP Cliet API: It provides a API to read or write ito LDAP or Policy Iformatio Base (PIB) [0] DB repository. Format Coversio & COPS Server Modules: They ecode ad decode policy rule(s) ito /from a COPS message ad trasfer it to/from appropriate policy targets. Policy target is a etwork elemet where the eforced policy rules are to be istalled. Most of the curret etwork elemets, however, are ot fully policy-based maagemet eabled. We eed a proxy approach i such a situatio. Our policy target architecture is desiged to be flexible eough to deal with both COPS-eabled etwork elemets ad legacy oes. It provides trasparecy i maagig multiple heterogeeous etwork elemets (NEs) via a NE idepedet API. Network elemet specific cofiguratio iterfaces are mapped to this commo API so that the cost ad efforts for developmet ad maagemet of the policy target ca be reduced.

5 3.2. Resource Moitorig Server RMS collects etwork s physical ad routig cofiguratio iformatio, performs auto-discovery of a target etwork topology ad simple resource statistic like IP iterface I/Out octets. Topology is ot limited to IP layer but icludes routig protocol specific ad MPLS layers. MPLS topology is further divided ito four sub-views: badwidth allocatio view, LSP traffic statistics based lik utilizatio view, lik affiity view ad forwardig adjacecy LSP view. With such diverse topological views, etwork admiistrators ca efficietly uderstad ad respod to etwork ad routig behaviors. For etwork topology auto-discovery, RMS first collects system, iterface ad lik iformatio from MIB II [] via SNMP pollig ad ivokes the topology builder methods i CSI topology classes. This method the triggers i sequece creatio ad registratio of correspodig odes, liks ad iterfaces via ode ad lik maager classes. Durig this process, various types of odes, liks, ad iterfaces are idetified give the iformatio from the system & iterface MIBs ad other cofiguratio iformatio. For example, a particular iterface of a ode ca oly support plai IP forwardig, MPLS forwardig or both. Foud objects are created accordigly. Oce the iitial step of topology buildig process is doe, it registers ewly discovered odes ad iterfaces ito RMS ad TMS servers for periodic statistics collectio. Figure 4 illustrates this process via a iteractio diagram ad a sample source code, which is a part of the topology builder iterface implemetatio. buildtopology () { NodeRef ode = NodeMaager::createNode( ); ode->createipnodemclassf( ) ; RMS DB ode->createipnodecclassf( ); IpTopology::registerNode(ode); // register to topologies MplsTopology::registerNode(ode) RMSIterface::registerNode(ode- >getaddress( ), ) // register to RMS LspStatCollector::registerNode(ode- >getaddress( ), ) // register to TMS } RMS SNMP Pollig Egie Figure 4: RMS Architecture Sice the various topologies are kow after auto-discovery process, RMS ca perform ad iitiate statistics moitorig processes such as iterface ioctet/outoctet data ad MPLS LSP SNMP Routers RMSIterface Classes CSI Classes for CLI-based pollig ProxyIterface Classes Typical C++ Classes Proxy Aget statistics collectio. Not all moitorig ca be performed by SNMP because some MIBs are ot supported by the etwork device vedors yet. For istace, may MPLS related MIBs are ot supported by the most vedors yet. Commad lie iterface (CLI)-based moitorig is used as a temporary alterative i such a case Traffic Measuremet ad Aalysis Server Traffic Measuremet, characterizatio ad aalysis is oe of the most importat fuctio i traffic egieerig. TE ca be efficietly realized based o correctly measured, aalyzed ad historical traffic data. Thus, TMS is the core egie of Wise<TE/PN>. Besides pollig-based moitorig, TMS also depeds o other mechaisms to collect ad process raw measuremet data such as cflowd [2], Cisco s Traffic Matrix System (TMS) [9] ad Juiper s MPLS statistics file [3]. The TMS maages three kids of traffic iformatio: prefix matrix, adjacet AS matrix, LSP statistics ad CE/PE-to-CE/PE statistics. The prefix, adjacet AS matrix ad CE/PE-to-CE/PE statistics are collected by cflowd mechaism. Cflowd cosists of cflowd mux, cflowd ad cflowd collector. Cflowd mux is resposible for hadlig raw data from Netflow-eabled etwork devices ad makig it available to cliets o the local host. Cflowd is resposible for maitaiig per-iputiterface tabular data for each device, ad passig it back to a cetral collector. Fially, cflowd collector retrieves tabular data from istaces of cflowd ad writes data i ARTS files [4]. The TMS uses these tools with mior modificatio to extract prefix matrices ad adjacet AS matrices. LSP statistics are also very importat data to be collected ad aalyzed. This statistics data collectio is tightly coupled with the etwork elemet vedors. Some support MIBs ad others oly allow CLI-based access to the data. Thus, we decided to use curretly available method to collect these data across multi vedor etwork devices, that is, CLI-based data collectio. Whe related MIBs are widely available, Wise<TE/PN> ca easily be modified to accommodate MIB-based data collectio. We also use other etwork elemet specific mechaisms such as Cisco s TMS ad Juiper s LSP statistics file selectively for the accuracy of the data i additio to the CLI-based data collectio.

6 TMS DB Measured Traffic Data (AS/Prefix Matrix) cflowd Cflowd wrapper classes cflowd Router Router Router CSI TMSIterface Classes LSP Statistics via CLI Classes for CLI-based pollig ProxyIterface Classes Typical C++ Classes h * t TMS Proxy Aget day 288 week 296 Figure 5: TMS Architecture Figure 5 shows sub-modules of TMS, relatioships with other Wise<TE/PN> fuctioal blocks ad mechaisms used for iteractios. Cflowd directly iteracts with routers ad CLIbased collectio is via a proxy aget. The table illustrates how we process the measured raw data. We store raw data ito four tables: day, week, moth ad year tables. Each table has differet measuremet itervals from 5 miutes to day. These statistics data is coveyed to its potetial users (e.g., GUI, PS, etc.) i two differet ways. LSP statistics data is a part of M classes i CSI ad, therefore, directly writte by TMS to CSI s correspodig M classes such as LspTuelM ad TtM via whe this data is available after CLI-based pollig. Prefix/adjacet AS matrix data is accessed by its users via TMS wrapper classes via agai. TMS, the, retrieves requested data from TMS DB ad coverts it ito data types, which is retured as method call retur value. We will explai how this data is used ad visualized to etwork admiistrators i sectio Routig Advisor for Traffic Egieerig h t 5 mi 30 mi 2 hour moth 360 day year 365 RATE performs routig cotrol fuctios ad various simulatios to assist the etwork admiistrators for cosistet policy provisioig i a maaged etwork domai. The etwork admiistrators eed to kow available routig path(s) for give costraits ad etwork resources status (e.g., utilizatio of liks) whe particular lik s attribute(s) are modified, a ew LSP is created or a existig traffic truk is moved from oe path to aother. Also, it is very useful to visualize what happes whe a ode or a lik fails For a log-term capacity plaig purpose, a global path optimizatio simulatio i a whole maaged etwork domai overcomes the limitatio of per- LSP olie path calculatio. Path availability check fuctioality eables efficiet way of a LSP setup. Our server residet costrait-based shortest path (CSPF) algorithm ca be used to compute the availability of the LSP path with desired costraits before actual eforcemet. Server-based CSPF ca exted its scope to add additioal costraits besides what olie CSPF allows. This feature is oe of big advatages that offlie TE server ca provide. Path attribute modificatio simulatio allows the etwork maagers to see the side effects of the modificatio such as lik utilizatio chages. The attribute chages rage from simple sigle attribute chage (e.g., affiity value) to a etire path for a LSP tuel chage. This simulatio helps the etwork maagers to create a detour route whe a particular lik is cogested ad see the lik state chages i real-time. Sice this feature is itegrated with real-time policy-based MPLS cofiguratio server, it ca serve as a very powerful tool to remove such cogested lik. Lik/Node failure simulatio depeds o olie protectio & recovery mechaism ad visualizes its effects. There are four cases: two for whether a primary is explicit or dyamic ad two for whether a secodary is explicit or dyamic. Depeds o the situatio, the simulatio ca just visualize the result or calculate a path usig server residet CSPF algorithm ad the visualize it. Global optimizatio simulatio is performed by the algorithms that we have developed. These practical algorithm ca fid ear optimal paths that satisfy the give traffic demad uder costraits such as user badwidth requiremet, measured traffic volume betwee a igress ad a egress routers, maximum hop cout, ad preferred or otpreferred ode/lik list. The mixed iteger programmig formulatio also calculates the traffic split ratio for the multiple paths. For easy implemetatio at etwork odes, the split ratio is chose amog discrete values (0., 0.2 etc.). The proposed algorithms are applied to the MPLS etworks that permit explicit path setup. The paths ad split ratio are calculated off-lie, ad passed to RATE for explicit label-switched path (LSP) setup recommedatio to etwork admiistrators. For more details, please refer to the paper. [5] 3.5. Topology ad Traffic iew Maager RMS ad TMS collect traffic data ad aalyze them ito meaigful iformatio as described i

7 A P A P L A P the previous sectios. These iformatio ca be much more useful whe they are visualized i orgaized maers. Topology ad traffic view maager does this role. Figure 6 illustrates three differet traffic statistics view: a adjacet AS matrix view, a prefix matrix view ad a MPLS statistics view. The adjacet AS matrix view represets traffic utilizatio betwee the maaged AS ad eighbor ASes i terms of Mbps. Each lik is divided ito two parts, each oe represets traffic directio origiated from the AS that the lik is attached to. Ad traffic volume is deoted by differet colors. The prefix matrix view shows similar traffic utilizatio betwee pairs of etwork prefixes of iterests. Ulike the AS matrix that shows iter-domai traffic volume, the prefix matrix is aimed to provide maaged etwork domai iteral traffic statistics. Thus, the prefix represets AS iteral etwork addresses. Also prefix level aggregatio is supported to provide flexibility ad uecessary iformatio filterig. The MPLS statistics view shows MPLS layer view. This meas that both layer two liks ad MPLS LSP tuel liks are show i the same topology diagram. This helps the etwork admiistrators idetifyig which oe is a logical MPLS tuel. The bloo help i the diagram provides this iformatio. It shows whether it is a LSP tuel, the actual layer 2 path ad traffic volume of that particular LSP tuel. Note that the lik color represets utilizatio i percetile ot i volume. Whe more details about the lik eed to be represeted (e.g., the umber of LSPs that belog to this lik), table format lik details ca be retrieved from the correspodig DB. Statistics Widow - AS Matrix iew Statistics iew Duratio: 200/05/5-200/06/5 Statistics iew Name: AS Matrix - My AS to Neighbor ASes + AS60 - AS620 AS700 AS620 AS 20 AS 200 AS220 Save MPLS iew - LSP Tuel Statistics Iter-AS Traffic: Mbps AS Seoul 00 Close AS600 AS240 AS50 AS500 LSP Tuel Itf: Tae-Suw-Seo, 600Mbps Help Kwagju Statistics Widow - Prefix Matrix iew Statistics iew Duratio: 200/05/5-200/06/5 Statistics iew Name: Prefix Matrix - Itra AS Prefixes /24 - Taejo / / / / /24 Figure 6: Traffic statistics view Besides these views, a badwidth reservatio view visualizes available/reserved badwidth o liks. Lik color (affiity) view visualizes liks colors i a traffic light form with Suwo Pusa Save Taegu / /24 Close LSP Statistics: % 0 ~ ~ ~ ~ ~ / / /24 Iter-Prefix Traffic: Mbps Help a color palette. Lik & tuel view visualizes L2 liks i oe color & LSP tuels i aother color. 4. Implemetatio Curretly, we have almost fiished prototype implemetatio of Wise<TE/PN> based o the desig priciples described i this paper. The complete prototypig will be doe by the ed of the third quarter of this year. System developmet is uderway o Su solaris platform. MICO [6] is used to implemet iterfaces of CSI ad other server modules. RMS pollig egie ad other server iteral fuctioality are implemeted i C++ laguage. COPS is built from the scratch based o IETF s COPS-PR specificatio [7] with C++ laguage. COPS server ad cliet protocol egie are desiged ad built with object-orieted methodology to be scalable for future extesio. POSIX thread is used to hadle a large umber of multiple policy target cliets ad maximize the system computatio resources. arious traffic data are stored i relatioal DB(s) to reduce performace burde. Although Solaris is the developmet OS eviromet, other OS types such as Liux ad FreeBSD will be supported as well. We use Java for GUI developmet for the obvious reaso, that is, the portability. Figure 7 shows a sapshot of our mai GUI iterface. The tree cotrol show o the left-had side ca be used to create, modify ad delete MPLS policy rules. User-friedly policy rule editig wizards are used for the ease of a cofiguratio process. Oce the rules are created ad stored, you ca eforce the rules either directly ito a specific etwork elemet of your choice or by a rolecombiatio. The policy-based etwork maagemet architecture by IETF recommeds usig role-based eforcemet oly but target specific oe ca be practically useful tool by etwork admiistrators who kow the etwork topology well. The topology view cavas o the right-had side depicts auto-discovered etwork topology from various viewpoits such as IP layer, OSPF, BGP ad MPLS view. It also shows traffic utilizatio status i colors. Simulatios are visualized i the separate widow to compare the existig etwork status with modified view by simulatio. Curretly, we have setup a test-bed to evaluate validity of our system. It cosists of eight commercial backboe routers (three 7000 series Cisco routers ad four M series Juiper routers ad oe MPLS edge router developed by a Korea compay, RAONET [8]). arious iterface types are supported such as Fast Etheret, Giga Etheret,

8 55 Mbps POS ad OC-3 ATM. They are almost fully coected so that we ca test diverse scearios. We have t started full-scale field test yet but are plaig to lauch that very soo. We expect that some test results ca be icorporated ito our ext versio of the paper. Figure 7: A Sap Shot of Mai GUI 5. Coclusio ad Future Work MPLS was proposed as a stadard TE solutio by IETF to address traditioal TE problems but practical problems durig deploymet process have bee idetified. I this paper, we proposed a powerful TE server solutio, Wise<TE/PN>, to overcome these limitatios. Yet, we have to add additioal fuctioality to make it more useful tool. Traffic statistics reportig fuctio is very importat i the real operatio sceario. Curret MPLS TE is for a sigle aggregated class type but QoS-based services require class type aware TE. Wise<TE/PN> ca be exteded to icorporate server-based DiffServ-aware MPLS TE. [9] As metioed i the itroductio sectio, ed to ed TE is the ultimate goal for true traffic egieerig. However, there are may challeges associated with this research area. We will look ito this problem very carefully. Lastly, optical etwork is becomig the choice of the backboe etwork for large-scale service providers. Our ext log-term step is, aturally, to research ad develop a solutio for a optical backboe etwork based o our Wise<TE/PN> architecture. Refereces [] E. Rose, A. iswaatha, R. Callo, Multiprotocol Label Switchig Architecture, RFC303, IETF, Ja [2] D.O. Awduche, et al., Overview ad Priciples of Iteret Traffic Egieerig, Iteret-Draft: draft-ietf-tewg-priciples- 00.txt, IETF, Feb [3] J. Boyle, The COPS (Commo Ope Policy Service) Protocol, Iteret Draft: draft-ietf-rap-cops-03.txt, 998. [4] J.D. Case, M. et al., Simple Network Maagemet Protocol (SNMP), RFC57, IETF, May [5] Juiper Network Ic., Traffic egieerig for ew public etwork, papers/ pdf, April, [6] OMG, The Commo Object Request Broker: Archtecture ad Specificatio, Revisio 2.2, Feb [7] H. Maho, et. al, Requiremets for a Policy Maagemet System, Iteret-Draft: draftietf-policy-req-02.txt, November [8] Yeog, W., Howes, T., ad S. Kille, "Lightweight Directory Access Protocol", RFC 777, IETF, March 995. [9] TMS, oduct/software/ios2/2ewft/2t/ 2t5/tms.htm, Cisco Ic. [0] M. Fie, et al., Framework Policy Iformatio Base, Iteret-Draft: draftietf-rap-frameworkpib-05.txt, IETF, July, 200. [] K. McCloghrie, M.T. Rose, Maagemet Iformatio Base for Network Maagemet of TCP/IP-based iterets:mib-ii, RFC23, IETF, March 99. [2] cflowd,

9 measuremet/cflowd/idex. [3] Juiper s stat file, ml. [4] ARTS++, [5] Y. Lee, Y. Seok, Y. Choi, C. Kim, Explicit Multipath Traffic Egieerig i MPLS Networks, submitted to Globecom200. [6] [7] K. Cha, et. al, COPS Usage for Policy Provisioig (COPS-PR), RFC3084, March 200. [8] [9] Fracois Le Faucheur, et al., Requiremets for support of Diff-Servaware MPLS Traffic Egieerig, Iteret-Draft: draft-ietf-tewg-diff-te-reqts- 0.txt, IETF, Jue 200. 관심분야 : MPLS-TE, Traffic Measuremet & Aalysis, IP Network Simulatio 정형석 995: 광운대학교컴퓨터통신석사 2000: 광운대학교컴퓨터통신박사 200- 현재 : ETRI 인터넷구조팀관심분야 : PBNM, MPLS-TE, 망관리, 김창훈 997: 서울대학교컴퓨터공학학사 999: 서울대학교컴퓨터공학석사 현재 : ETRI 인터넷구조팀연구원관심분야 : MPLS-TE, IP Routig 박정숙 2000: 효성가톨릭대학컴퓨터공학박사 현재 : ETRI 인터넷구조팀연구원관심분야 : Traffic Measuremet ad Aalysis, MPLS-TE 최태상 미주리-캔사스주립대박사 ~ 998: ETRI 멀티미디어통신팀 999 ~ Preset: ETRI 인터넷구조팀관심분야 : - QoS Maagemet ad Traffic Egieerig i IP Networks - Iteractive Multimedia Service System - Network, System, ad Service Maagemet 윤승현 996: 성균관대학교산업공학박사 현재 : ETRI 인터넷구조팀연구원 이병준 996: 서울대학교컴퓨터공학학사 998: 서울대학교컴퓨터공학석사 2000: 서울대학교컴퓨터공학박사수료 : 에슈컴코리아개발팀장 현재 : ETRI 인터넷구조팀연구원관심분야 : MPLS, PN, XML 정태수 983.2: 경북대학교전산학석사 ~ 현재 : ETRI 인터넷구조팀관심분야 : - Iteret & Data Networks

10 - Telecommuicatio Systems - Network Maagemet