Service-Oriented Multi-Granular Optical Network Testbed
Descrição do Produto
ServiceOriented MultiGranular Optical Network Testbed Yixuan Qin 1 , Georgios Zervas 1 , V. Martini 2 , Malek Ghandour 1 , Michele Savi 3 , F.Baroncelli 4 , B.Martini 4 , P.Castoldi 2 , Carla Raffaelli 3 , Martin Reed 1 , David Hunter 1 , Reza Nejabati 1 , Dimitra Simeonidou 1 1 Department of Computing and Electronic Systems, University of Essex, Colchester, UK, CO4 3SQ Tel: +441206872404, Fax: +441206872900, { yqin , gzerva, mghand, mjreed, dkhunter , rnejab, dsimeo}@essex.ac.uk 2 Scuola Superiore Sant'Anna, Pisa, Italy, {v.martini , castoldi}@sssup.it 3 Department of Electronics, Informatics and Systems, University of Bologna, Viale Risorgimento 2, Bologna, ITALY {michele.savi, carla.raffaelli}@.unibo.it 4 CNIT, Pisa, Italy, {barbara.martini, fabio.baroncelli}@cnit.it
Abstract: This paper presents a serviceoriented multigranular multiformat network demonstrator. Serviceoriented wavelength and subwavelength network connection establishment is being demonstrated by utilising SOONJIT protocols to support VoD HD and QuadHD multimedia applications. ©2005 Optical Society of America OCIS codes: (060.4250) Networks; (060.2330) Fiber optics communications
1. Introduction A new generation of applications is emerging which demands access to remote computing resources, distributed data storage facilities, media servers, content repositories and scientific instruments, often via highspeed network infrastructures. Initially developed by collaborative virtual research communities, these applications are steering the development of new serviceoriented network technologies and architectures [1]. Reciprocal awareness between applications and networks is recognized as a fundamental step towards the implementation of next generation networks. Entire classes of emerging network applications (e.g. grids, SHD on demand multimedia services) will rely on advanced service and network control plane technologies, for the optimized management, (scheduling, access and use) of the underlying network and IT infrastructure. This paper presents results of a novel serviceoriented multigranular Ethernet optical bust switching (EOBS) and transport (EOBT) network demonstrator for the support of future Internet applications. The experimental validation of the concept relies on the demonstration of QuadHD videoondemand (VoD) services over the E OBS testbed. The network architecture is based on the integration of service oriented optical network (SOON) framework functionalities with EOBST control and data plane technologies [2]. We demonstrate that the proposed SOONenabled OBS architecture can be used to effectively bridge the informational gap between the Application layer and the Network layer by introducing a suitable formalism that facilitates a mapping process between Application requests and the Network services. The SOON framework is based on a distributed approach conceived for overseeing a new paradigm of applicationtonetwork interaction. The aim is to disjoint the parameters perceived by an end user from the technologyspecific directives needed by network devices. It also enables automatic network configuration for establishing ondemand connection with different classes of service. In this implementation, the SOON framework is able to map a set of parameters that an application (e.g. multi media) specifies within a network service request, into a set of specific parameters used by the network (e.g. edge aggregation buffer thresholds, offset, lambda/sublambda lightpaths) while hiding the network resource technology
Fig. 1. Architectural block diagram of the SOONenabled EOBST testbed and network demonstrator
and topology details from the application. SOON also translates this mapping into a direct request for dynamic configuration of that service. The EOBST network is then able to parse the SOON request and configure aggregation scheduler (buffer size, time) on the fly, select the appropriate granularity (burst size over lambda/sub lambda) and establish lightpaths (slowfast path) to support different services. 2. SOONenabled EOBST Network: Network Architecture, Testbed Setup and SOON Results The proposed serviceoriented network architecture is based on SOON elements and EOBST technologies utilizing serviceaware edge and core routers interconnected by JITSOON signaling. The SOON translates applications’ service requests expressed in terms of perceived QoS and resources to technologyspecific pool at the edge of the EOBST network. Through this capability of decoupling network technologies from services, the control plane (CP) is unburdened of serviceoriented functionalities and it can focus on the provisioning of connectivity services. The SOON supports Service Abstraction and Resource Virtualization capabilities that allow to map a set of application specific parameters in to a set of parameters used by the network for the actual configuration of a service while avoiding from exposing the network resource technology details to the applications. Network specific parameters are: burstdimension, offsettime, network provisioning service (EOBSEOBT) and endtoend lightpath. The SOON framework has also the ability to coordinate the different OBSedge devices to create unidirectional and bidirectional endtoend wavelength (EOBT) and subwavelength (EOBS) paths. This is obtained through an adhoc signaling protocol among Distributed Service Element (DSE) which can exchange the edge characteristic and reachability information. The DSE also manages the periodical update of information regarding the edge node devices used to solve the reachability of source/destination through the network resource DB (NRDB) internal database. To enable the framework to interact with the OBS network a specific technologydependent module installed in each DSE has been conceived which translates the information received from the DSE into a set of specific directives comprehensible by the EOBST devices. The serviceaware edge OBS router which utilizes network processor and FPGA (Field Programmable Gate Arrays) devices operating at 1GE (server/client side) and 2.5 Gbps (EOBST control plane and data plane) is able to differentiate between service layer messages (based on SOON), network requests and data packets. In case of SOON signaling messages the edge router forwards them to the control plane. In case of incoming SOON network requests, the burst aggregation scheduler is been triggered to reflect service requirements into buffer size and the time thresholds. The SOON message is also used to decide on the network provisioning system of either EOBS or EOBT and then the appropriate lightpath (one out of maximum four). The EOBS provisioning system is created by aggregating bursts and generating and transmitting a burst control header (BCH) ahead of time (5μs) in order to configure the acoustooptic switch on per burst basis. EOBT supports an endtoend lightpath for the duration of the service by generating a BCH after the SOON message is received. Finally, the combination of lambda selection by controlling a SGDBR tunable laser (at Edge 1) connected to a MEMS switch (for connectivity with all core nodes) together with the BCH processed at the core FPGA provides the endtoend dynamic lightpath. Finally the data packets are being buffered on aggregation FIFOs and then transmitted over different wavelength or sub wavelength lightpaths. The EOBST data plane transport mechanism is based on keepalive messages inbetween burst transmission. The serviceaware core OBS router comprises of three nodes all controlled by a centralized FPGAbased control plane module creating a meshed topology. The two nodes consist of MEMS switches (10ms) and the third one of both MEMS switch and acoustooptic switch (4 μs) to form a multigranular optical crossconnect (MGOXC). The control plane module utilizes network processor and FPGA and it can process and forward service layer information SOON Signalling
Directives for EDGE node configuration
Service Request from Application SOON processing
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ACK back to Application
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Fig. 2. SOON edgetoedge overall provisioning time
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on the fly as well as allocate switch resources for either EOBS or EOBT provisioning. The EOBS traffic is transported using a specific lightpath through the MGOXC node and switched at the acoustooptic switch supporting service 2 (section 3). The rest of the traffic is being transported over three different lightpaths (service 1) having different number of hops based on EOBT for the duration of the service. Unlike the existing service oriented architectures, which uses the legacy IP network for carrying SOON signals and messages, in the proposed architecture SOON messages are carried in the optical domain with JIT signalling and within the burst control header (BCH). The GUI service application issues a request to the SOON framework for a specific network service (four network services). Then, the DSE element uses proprietary signalling to trigger the other involved DSE and configures the OBS devices. The SOON signalling is service specific and has different message set for each type of provided service. Figure 2 shows, the overall time elapsed during the SOON network service provisioning process. The first section (from the left) of the figure represents in the SOON processing time of service request before starts the signalling (blue peak), while the second block representing the processing for the building of specific directives for edge node configuration (pink peak) inferred from the user request. After the edge configuration the SOON gathers the ACK message from the DSE module and sends a serviceprovided ACK to GUI service application (red line). The SOONJIT control protocol performance has been evaluated by measuring the endto end service time which includes the edge and core node parsing and forwarding time. The result is shown in Figure 2a. This value is mostly dependent of the end host performance used for SOON elements and not the actual EOBS T testbed. 3. Network Service Results In this experiment, SOON service and connection establishment as well as high definition video over EOBST transmission are demonstrated. The SOONJIT messages encapsulated in BCHs are sent over EOBST control plane and the generated variable optical bursts over Ethernettype data plane. In order to study the effect of EOBS T on the realtime transmission of high performance media, four prerecorded videos, with different qualities, were used in different streaming media scenarios across the OBS network testbed. These videos varied from high definition with resolutions of 1280x720 and 1440x1080 and bitrates of 27 Mbps and 46 Mbps respectively, to QuadHD of 2560x1600 and bitrates of 106 and 156 Mbps. The TCP background traffic of around 200Mbps was also generated through traffic generator in order to emulate the current internet traffic behaviour (between TCP and UDP data). The aggregation developed is hybrid and combines both size and time thresholds which are also dynamically changed per SOON service with maximum size threshold of 5000 bytes and time limit of 2ms. Figure 3a shows that for service 1 (EOBT) more than 95% of the UDP packets have a delay of less than 3 ms with a maximum delay less than 4ms which is well within the acceptable level and for service 2 the value is less than 1.8ms. Figure 3b shows that for service 2 (EOBS) the jitter also remains below 1.4 ms for 100% of the traffic and below 0.9ms, again a well accepted value. The packet loss of the OBS network is zero the whole amount of data.
Fig. 3. a) Delay and b) Jitter of receiving 46Mbps High Definition Video over the EOBST testbed which has 200Mbps background TCP traffic. Service 1 is defined and implemented in the edge node (FPGA) as best effort class. Service 2 is defined and implemented in the edge node (FPGA) as timing critical class. Acknowledgment: The work described in this paper was carried out with the support of the BONEproject (“Building the Future Optical Network in Europe”), a Network of Excellence funded by the European Commission through the 7th ICTFramework Programme.
4. References [1] Dimitra Simeonidou, et.al., "Dynamic Optical Network Architectures and Technologies for Existing and Emerging Grid Services", IEEE Journal of Lightwave Technology (JLT), Volume 23, Issue 10, Page(s):3347 – 3357, Oct. 2005 [2] F. Baroncelli, B. Martini, V. Martini, and P. Castoldi "A distributed signalling for the provisioning of ondemand VPN services in transport networks, Integrated Network Management (IM) 2007, Germany, Munich , May 2007
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