, pp.69-80 http://dx.do.org/10.14257/jmue.2014.9.9.08 A Traffc Aware Routng Protocol for Congeston Avodance n Content-Centrc Network Jung-Jae Km 1, Mn-Woo Ryu 2*, S-Ho Cha 3 and Kuk-Hyun Cho 1 1 Dept. of Computer Scence, Kwangwoon Unversty 447-1, Wolgye-dong, Nowon-gu, Seoul 139-701, Sou Korea {kjj6929, chokh}@kw.ac.kr 2 Embedded Software Convergence Research Center, Korea Electroncs Technology Insttute #68 Yatap-dong, Bundang-gu, Seongnam-s, Gyeongg-do, 463-816 Sou Korea mnu@ket.re.kr 3 Department of Multmeda Scence, Chungwoon Unversty 113, Sukgol-ro, Nam-gu, Incheon, Sou Korea shcha@chungwoon.ac.kr Abstract Content-Centrc Network (CCN) s next generaton nternet communcaton technology to provde exstng nternet communcaton paradgm as content based communcaton for effcent use varous nformaton n e Internet. Therefore, unlke exstng nternet communcaton technology, whch focus on host based communcaton process, all of resource s defned as contents n CCN. Moreover t focuses on purpose of communcaton for usng nformaton. CCN communcate w between routers rough broadcast floodng meod n er network envronments. Ths characterstc of CCN s not consderng ncreasng network traffc about each of CCN routers. Therefore, when e requesters are rapdly ncreased to partcular CCN router, network congeston may be occurred by broadcast traffc. Moreover, s characterstc of CCN has low turnaround tme about user request due to reducng performance of network system. To resolve s problem, s paper proposes a traffc aware routng protocol for congeston avodance n CCN. The proposed routng protocol consders rapdly ncreasng traffc n e stuaton and establshes anoer routng pa to avod ncreasng traffc problem n CCN. Keywords: Traffc, Content-Centrc Network, Routng, Protocol, Congeston Avodance 1. Introducton Through numerous hardware technology advances, many devces were developed. And s stuaton s movng towards dssemnaton of multmeda based devces such as smart phone and tablet. Accordng to e stuaton, people can connect e Internet an any-tme, any-place. Theses paradgm has change of usng e Internet. For example, e tool, whch s used to e Internet, s movng towards from personal computer to multmeda devces. And also, usng of nternet nformaton s moved from exstng web page to moble web or multmeda contents. Throughputs eses paradgm, new technology have emerged so-call Content-Centrc Network (CCN). CCN s next generaton nternet communcaton technology to change exstng nternet communcaton paradgm as content based communcaton for * Correspondng auor ISSN: 1975-0080 IJMUE Copyrght c 2014 SERSC
effcent use varous nformaton n e Internet [1]. Therefore, unlke exstng nternet communcaton technology, whch focus on host based communcaton process, all of resource s defned as contents n CCN. Moreover t focuses on purpose of communcaton for usng nformaton. For e change of eses communcaton purpose, CCN communcate w each CCN router va name based routng meod and contents s saved n each CCN router. Therefore, CCN has dfferent communcaton meod exstng nternet communcaton technology. CCN communcate rough e Interest packet and e Data packet. The Interest packet s used to when requester request contents to publsher. And e Data packet s used to when publsher response contents to requester [2]. Therefore n CCN, routng meod was performed by e Interest packet and e Data packet. In ere, CCN router broadcast e Interest packet to neghbor routers for fndng nterest contents. If CCN router s fned nterest contents, t s create e Data packet and response t to requester va pa tracng of e Interest packet. Ths characterstc of CCN s not consderng ncreasng network traffc about each of CCN routers [3]. Therefore, when e requester requests are rapdly ncreased to partcular CCN router, network congeston may be occurred by broadcast traffc [4]. Moreover, CCN has low network performance. Ths s because, CCN do not consder congeston avodance n mult pa routng. Ths problem occur low qualty data servce to user due to reducng network performance [5-6]. To resolve s problem, s paper proposes a traffc aware routng protocol for congeston avodance n CCN. The proposed routng protocol consders rapdly ncreasng traffc n e stuaton and establshes anoer routng pa to avod ncreasng traffc problem n CCN. The rest of s paper s organzed as follows. The exstng routng protocol used n s research feld s ntroduced n Secton 2. Basc dea and overvew about e proposed routng protocol s ntroduced n Secton 3. Secton 4 descrbes e proposed routng protocol. Secton 5 presents a performance evaluaton of e proposed routng protocol by comparng t w e exstng CCN routng. Fnally, n Secton 6, conclusons are made ncludng e future research. 2. Related Work 2.1. Content-Centrc Networks (CCN) Unlke exstng nternet communcaton meod, e CCN communcate rough name of contents nstead of IP address. Therefore, n e CCN, contents name s eased to search va prefx matchng due to contents name s desgned as herarchy. In addton, CCN communcaton rough e Interest packet and Data packet. The Interest packet s used to when requester request contents to publsher and t has requested nformaton such as content name and requester nformaton. The Data packet s used to when publsher response contents to requester and t has contents name, nformaton about verfcaton, and drect data. Fgure 1 shows structure of CCN router. As shown n Fgure 1, CCN router has ree of structure such as Content Store (CS), Pendng Interest Table (PIT), and Forwardng Informaton Base (FIB). The CS has role of buffer memory n CCN router. It has specal storage and t s cachng from passed all of content rough LRU cachng polcy about contents e nsde of CCN router. The PIT tracks Interests forwarded upstream toward content source(s) so returned Data can be sent down- stream to ts requester(s). The FIB s used to forward Interest packets toward potental source(s) of matchng Data. It s almost dentcal to an IP FIB except t allows for a lst of outgong faces raer an a sngle 70 Copyrght c 2014 SERSC
one. Ths reflects e fact at CCN s not restrcted to forwardng on a spannng tree. It allows multple sources for data and can query em all n parallel. Fgure 1. Router Archtecture for CCN In e CCN, whch has above structure, t s not provded effcent data servce due to CCN do not consdered traffc of nodes n case of network traffc s rapdly ncreasng. To resolve s problem, s paper proposes a traffc aware routng protocol for congeston avodance n CCN. The proposed routng protocol consders rapdly ncreasng traffc n e stuaton and establshes anoer routng pa to avod ncreasng traffc problem n CCN. 2.2. Actve Queue Management Actve Queue Management (AQM) can execute program, whch s specal program n case of need process n nsde CCN router when congeston s occurred. Ths s mean; AQM can rapdly process of congeston control rough transmsson pa of packet an exstng oer congeston controls [7]. In s paper, we apply e concept of Random Early Detecton (RED) [8] for measurement of traffc load among AQM process. RED was desgned for sensng of congeston n packet swtchng network. In RED, e Control packet s dscarded accordng average queue leng, whch s calculated by probablty when leng of queue s exceeded reshold. In oer words, RED algorm compare max reshold (max ) and mn reshold (mn ), whch are predefned va calculatng of average queue leng n every packet was arrved. In RED procedure, RED has polcy as follows: If average queue leng s greater an mn reshold, RED has normal condton If average queue leng s greater an mn reshold and s less an max reshold, nput packets s randomly dscarded. If average queue leng s greater an max reshold, all of nput packets s dscarded. Fgure 2 shows drop probablty about average queue leng n RED. Copyrght c 2014 SERSC 71
Fgure 2. Packet Drop Probablty of RED Algorm However, RED does not apply to CCN because t s dfferent of nternet communcaton mechansm. Therefore, n s paper, we proposed a Traffc Aware Routng Protocol (TARP) for congeston avodance n CCN usng concept of AQM and RED 3. Routng Overvew 3.1. Notatons Unlke exstng networks, e proposed TARP do not perfectly apply to RED due to t s performed n CCN envronment. Therefore, we s used to only concept of RED. The table 1 lst e symbols used n e proposed TARP. Table 1. The Defnton of Routng Meod Symbols Symbols N cur q avg q mn max Defntons The - router node Current queue leng of N Average queue leng of N The mn reshold of queue The max reshold of queue P drop Drop probablty of e Interest packet n N T delay Predefned value for delay e Interest packet n N Pa n(face) Interest Transmsson pa of content Number of current FACE The Interest packet Random p Probablty of generated random between 0 to 1 overt delay 3.2. Overvew The delay tme at s proportonal to e average queue leng The proposed TARP conssts of 2 meods. The frst meod s processed e Interest packet based on average queue leng by probablty when average queue leng s greater 72 Copyrght c 2014 SERSC
an mn reshold and s less an max reshold. The second meod s dscarded e Interest packet when average queue leng s greater an max reshold. Fgure 3 show operaton process of TRAP Fgure 3. TARP Formaton The router of TARP s defned by nternal condton of router. The detal descrpton s as follows: overn : current overloaded node. In oer words, average queue leng of N s greater an max. nn : overloaded node. In oer words, average queue leng of N s greater an max and s less an mn undern : dle node. In oer words, average queue leng of N s less an mn All of router has at least on among above condtons. In condton of undern, ere s no restrcton when e Interest packet s transmtted by router and content s delvered to anoer router. Therefore, n case of undern, e router has same routng meod as CCN. However, n case of overn, traffc condton of e router s saturaton. Therefore, traffc of N s rapdly ncreased due to broadcastng of e Interest packet. In addton, congeston control s generated by s stuaton n N. In e end, s stuaton leads to reducng network performance. To resolve s problem, e TARP s dscarded nterest packet whch are receved anoer CCN router. Thus, e router s not selected n transmsson pa of e Data packet. In case of nn, e condton s not generated reducng network performance. However, e condton may generate reducng network performance when traffc s ncreased. Therefore, n s stuaton, e TARP calculates P drop accordng to avg q of N. And e TARP decdes delay of e receved Interest packet n N. Through s, e TARP prevent congeston control n beforehand to exclude tself form creaton of Pa. 4. Routng Meod In s secton, we ntroduced routng meod of e TARP. In e TARP, all of routers, whch wll receve e Interest packet, ndependently partcpate to establsh of route accordng to traffc emselves. Copyrght c 2014 SERSC 73
4.1. Basc algorm In TARP, establshng of route s started va broadcastng of e Interest packet to fnd contents, whch are requested from request, as smlar exstng CCN routng. Therefore, relay nodes, whch receved e Interest packet, transmt e Interest packet untl destnaton node and establsh of response routng pa to PIT of emselves. After above process, e destnaton node traces e node whch frstly receved e Interest packet and transmts e Data packet ncludng content to requester va uncastng. In s process, e relay nodes, whch receve e Interest packet, can partcpate to establshng of route rough delay of e Interest packet or dscardng of e Interest packet based on traffc condton of emselves. In oer words, e relay nodes may can exclude emselves from establshng of route n case of nn or cjtqjs Ths can establsh routng pa whch can avod nodes whereby generatng of congeston n network. Moreover, s may can reduce generaton of congeston n e network. All of nodes calculate average queue leng of own queue for establshng of Pa when e Interest packet s arrved. In s procedure, we apply exponental weghted movng average (EWMA) [9] as formula (1) for tolerance of traffc whch s arrved to N at moment when calculatng of avg q. avg q = (1 w q ) avg q. + W q q (1) In e formula (1), w q represent flter weght value of EWMA and defne 0.002 as default value. And q represents new calculated leng of queue. The table 2 show procedure when nterest packet s arrved. Table 2. Procedure when Interest Packet Arrves Lne 2-10 descrbe routng meod when condton of N s become undern. And lne 3-9 descrbe routng meod when condton of N s become nn. Routng meod when condton of N s become overn s descrbed n lne 10 to 17. The each of detal descrpton s ntroduced n Secton 4.1, and Secton 4.2 74 Copyrght c 2014 SERSC
4.1. Meod 1: nn The Meod 1 represent processng meod when avg 1 q s greater an mn and s less an max. In s condton, drop probablty of e Interest packet can be obtaned usng formula (2). p P n over P max ( avg max ( avg max q q mn mn mn mn ) ) mn (2) Where e P n represent dscarded probablty when N s nn. The p over represent drop probablty when N s overn. As shown formula (2), e greater e average queue leng (e larger e traffc), e greater e delay probablty. In TARP, relay nodes process e Interest packet based on queue condton of emselves usng formula (2). Fgure 4 shows drop probablty n TARP. Fgure 4. Probablty of Applyng e Second Formula In exstng RED, all of node dscards e Interest packet when average queue leng s exceeded max reshold. However, n s case, f any node s relay node and relay node s only one n e network, trunaround tme of content has hgh delay due to e Interest packet drop s generated untl resolvng congeston. Fnally, e network perforce s reduced. On e oer hand, e proposed TARP can be mprovng survval probablty of e Interest packet va formula (2). In e proposed TARP, calculated drop probablty from formula (2) s compared w Random p. In s procedure, f calculated drop probablty s less an Random p, e TARP regards condton of N as undern. Therefore, e Interest packet s broadcasted to anoer neghbor node. On e oer hand, f calculated drop probablty s greater an Random p, e TARP delay broadcastng durng predefned T delay. Therefore, overloaded node delay creaton of Pa durng T delay. Ths reason s at overloaded node exclude for preventon of congeston n e network. 4.2. Meod 2: overn The Meod 2 represents processng meod when avg 1 q s less an mn. The Meod 2 performs as smlar of e Meod 1. However, f drop probablty, whch s obtaned P over n formula (2), s less an Random p, e Interest packet s dscarded. But f drop probablty s Copyrght c 2014 SERSC 75
greater an Randomp, e Interest packet s delayed as equal of e Meod 1. However, n case of s procedure, current node N has traffc saturaton. Therefore congeston s generated n e network when N s selected relay node. To resolve s problem, n e Meod 2, creaton tme of e Interest packet s forcbly ncreased as much as over T delay by condton of current queue. The over T delay s obtaned usng formula (3). over T delay T delay avg ( max q 5. Performance Evaluaton mn max ) In s secton, we analyze and compare e performance of e proposed TARP and exstng CCN usng OPNET to prove e valdty of e proposed TARP. In s performance evaluaton, we consdered e roughput accordng to nput load and average turnaround tme of contents. In e smulaton, each of e lnk bandwd s defned 100Mbps and lnk delay s defned 10ms. And also we added traffc at every 3-hop for makng of rapdly ncreased traffc. Table 3 summarzes our smulaton parameters. (3) Table 1. Smulaton Parameters Parameters Values Lnk bandwd Lnk delay Control packet sze Data packet sze 100 Mbps 10 ms 96 bytes 1024 byte Number of packets 20 ~ 120 Moreover, envronment of smulaton about network conssts of server, user, and routers. Where server has content and e Interest packet s created by user. Fnally, routers are used to transmt e Interest packet to server. In addton, we constructed mash topology for establshng of mult pa and regularty of structure. Fgure 5 show our network model of smulaton. Fgure 5. Network Model of Smulaton 76 Copyrght c 2014 SERSC
Fgure 6 shows roughput accordng to nput load. In e fgure 6, e more nput load ncreased, e roughput decreased. When we compare CCN, e proposed TARP has hgher performance an CCN. In partcular, n case of exstng CCN, roughput s rapdly reduced when nput load s exceeded of 1000 Kbps. On e oer hand, e proposed TARP s slower reduced an exstng CCN. Ths s because e proposed TARP prevent rapdly reducng roughput va avodance of congeston stuaton n prevously. Fgure 6. Throughput Accordng to Input Load Fgure 7 shows average turnaround tme of contests accordng to number of packets. In s fgure, larger number of packets led to hgher average turnaround tme n CCN and e proposed TARP. However, e average turnaround tme of contents lower an exstng CCN. Moreover, dfference of turnaround tme between e proposed TARP and exstng CCN s from mnmum 20 msec to maxmum 100 msec. Ths s because, e proposed TARP exclude overloaded routers n response routng pa. Therefore, e proposed TARP has shorter turnaround tme of contents an exstng CCN. Fgure 7. Average Turnaround Tme of Contents Copyrght c 2014 SERSC 77
6. Concluson and Future Work In s paper, we proposed TARP for avodance n congeston when traffc s rapdly ncreased n e CCN. The proposed TARP decdes partcpaton about establshng pa of route accordng to condton of average queue leng. Moreover, we were proved e proposed TARP much better an e exstng CCN rough smulaton such as roughput accordng to nput load and average turnaround tme of contents. However, e completed Interest packet, whch was used for respondng of contents, stll remans n e network. Therefore, ncreasng of traffc stll exsts. Future research wll nclude dstncton of e completed Interest packet and management of sole relay node accordng to traffc saturaton. References [1] B. J. Lee, H. S. Jeon, and H. Y. Song Informaton-Centrc Networkng Research Trend, Electroncs and Telecommuncatons Trends, (2012). [2] V. Jacobson, D. K. Smetters, J. D. Thornton, M. F. Plass, N. H. Brggs and R. L. Braynard, Networkng named content, In Proceedngs of e 5 ACM Internatonal Conference on Emergng Networkng Experments and Technologes, (2009), pp. 1-12. [3] L. Wang, A. K. M. Mahmudul Hoque, C. Y, A. Alyyan and B. Zhang, OSPFN: An OSPF Based Routng Protocol for Named Data Networkng, Techncal Report NDN Techncal Report NDN-2012-13, July (2012). [4] C. L, W. Lu and K. Okamura, A Greedy and Colony Forwardng Algorm for Named Data Networkng, n Proceedngs of e APAN - Network Research Workshop, (2012). [5] J. Moy, OSPF verson 2, RFC 2178, (1998). [6] J. Moy, "OSPF protocol analyss", Network Workng Group, (1991) July. [7] G. Thruchelv and J. Raja, A Survey on Actve Queue Management Mechansms, IJCSNS Internatonal Journal of Computer Scence and Network Securty, vol. 8, no. 12, (2008) December. [8] S. Floyd and V. Jacobson, Random Early Detecton Gateways for Congeston Avodance, IEEE/ACM Transactons on Networkng, (1993) August. [9] J. Stuart Hunter, The Exponentally Weghted Movng Average, Journal of Qualt Technology, vol. 18, no. 4, (1986) October. Auors Jung-Jae Km, he receved hs B.S. n Computer Scence from Kwangwoon Unversty, Seoul, Korea n 2013. He s currently workng on M.S. at e Department of Computer Scence, Kwangwoon Unversty, Seoul, Korea. Hs research nterests nclude content-centrc networks, vehcular ad-hoc networks, and wreless sensor networks. Mn-Woo Ryu, he receved hs B.S. n Internet Informaton Processng from Yeoju Insttute of Technology, Korea n 2007, and hs M.S. and Ph.D n Computer Scence from Kwangwoon Unversty, Seoul, Sou Korea, n 2009 and 2012, respectvely. He worked as a senor researcher n e Convergence Emergng Industres R&D Dvson at e Korea Electroncs Technology Insttute (KETI), Seongnam, Sou Korea. Hs research nterests nclude Vehcle Ad Hoc Networks, Informatoncentrc Networks, Internet of Thngs, and Semantc based Servce. 78 Copyrght c 2014 SERSC
S-Ho Cha, he receved hs B.S. degree n Computer Scence from Sunchon Natonal Unversty, Sunchon, Korea, n 1995, and hs M.S. and Ph.D. degrees n Computer Scence from Kwangwoon Unversty, Seoul, Korea, n 1997 and 2004, respectvely. From 1997 to 2000, he worked as a senor researcher at Daewoo Telecom and he also worked as a researchn-charge at Wareplus n Korea from 2004 to 2005. He s now an Assstant Professor n e Department of Multmeda Scence, Chungwoon Unversty, Incheon, Korea. Hs research nterests nclude network management, vehcular ad hoc networks, and wreless sensor networks. Kuk-Hyun Cho, he receved hs B.S. degree n Electronc Engneerng from Hanyang Unversty, Seoul, Korea n 1977 and hs M.S. and Ph.D. degrees n Electronc Engneerng from Tohoku Unversty, Senda, Japan n 1981 and 1984, respectvely. Snce 1984, he has been a Professor n e Department of Computer Scence and Engneerng, Kwangwoon Unversty, Seoul, Korea. From 1998 to 2000, he was Presdent of Open Standards and Internet Assocaton (OSIA). Hs research nterests nclude network and servce management, wreless sensor networks, and vehcular ad hoc networks. Copyrght c 2014 SERSC 79
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