Meridian: An SDN Platform for cloud networking services

Meridian: An SDN Platform for cloud networking servicesGuided by,Savitha MurthyAssoc. Prof,Dept., Of CSE,PESIT.

Presented by,Akshitha.H.MI sem, MTech, CSE,PESIT.1IntroductionTodays enterprise information technology environments must be highly responsive and agile n order to support rapidly changing business requirements .Cloud computing platforms offer a new IT consumption model that enables enterprises to procure computing resources on an as-needed basis and delegate management of the infrastructure to the cloud service provider.The number and variety of applications moving to cloud grows, cloud service providers have expanded their offerings to include a variety of services beyond 1. basic virtual servers 2. storage volumes 3. network connectivity

2Commercial cloud platforms today supports variety of 1. Server types (processing with GPU). 2.Multiple Storage Models (object, block). 3.Virtual Network.Cloud networking features have developed recently . ex: 1). Amazons AWS - IP connectivity to VPC 2).Openstack - Quantum

AWS and Openstack -network or device centric cloud networking models. -users must configure --switches, subnets, ACLS -used by their cloud applications to create virtual topology

This model mimics the traditional nature of IT management .

3In cloud - managing the network - virtualized version - functions as the physical network Service level model of cloud networking Emergence of SDN - integrate application provisioning in the cloud with the network through programmable interfaces and automation.

4Hence, this describes the architecture and implementation of Meridian ,an SDN controller platform that supports a service level model for application networking in clouds.

It also describes some of the challenges in design and implementation including how to efficiently handle dynamic updates to virtual networks, orchestration of network tasks on a large set of devices, and how meridian can be integrated with multiple cloud controllers.5Traditional Computer Networks

Data flow is controlled by switches and routers and contains the following basic elements:Data Forwarding plane: Packet streamingControl plane: Routing algorithmsManagement plane:Configure basic activities6Introducing Software-Defined Networking Software Defined Networking (SDN) is an emerging network architecture where network control plane is decoupled from forwarding plane and is directly programmableLead by Open Networking Foundation(ONF)

SDN-enabled control plane allows the underlying infrastructure to be abstracted

Network appears to the applications as a single, logical switch entity7Southbound API(eg. OpenFlow)

OpenFlow SwitchesBusiness ApplBusiness ApplBusiness ApplNorthbound APIINFRASTRUCTURELAYERCONTROL LAYERAPPLICATIONLAYERSDN CONTROL SOFTWARE8Meridian SDN Cloud Networking platform Architecture

9It is organized as three main logical layers 1).Network model and API 2).Network Orchestration 3).Network driver layer

10Abstract API layer

Present application with a network modelAssociated APIs that expose only the information needed to interact with the networkLogical view of the network using high-level APIs11Network Orchestration platform

Logical-to-physical translation of commands issued through the abstraction layer.Convert API calls into the appropriate series of commands on the underlying networkNetwork-wide service to application. ex: Topology view, notification of changes in link availability.Path computation according Different routing algorithmsGlobal annotated view of the data center topology for applications Planner module that can schedule network configuration or control task12Network driver layerConsists of plug-in or drivers enable the controller to interface with various network technologies or tools.The orchestration layer uses these drivers to issue commands on specific devices or collect information from the network.Meridian-Implemented a logical driver that interfaces to OpenFlow devices.Drivers to enable virtual network creationTopology data gathered

13Meridian implementationMeridian prototype is build on the open source floodlight controller platform.Floodlight is a modular java based (OpenFlow controller) that provides OpenFlow protocol support and a number of services such as (1). Basic link discovery. (2).Routing for open-flow enabled switches.

Extending Floodlights native support, and some new modules to implement the meridian architecture.

14Meridian network Abstraction ModelApplicationMiddlewareOSVMEndpoint (VNI,VM)Group( same connectivity properties)This model allows users to think of networking in terms of logical topologies for theircloud-basedapplications.

Meridian provides aservice-levelnetwork model for users to specify logical connectivity and policies or services associated with the virtual links between VMs.

In the Meridian network service model, five types of entities are defined:1).2.)15Segment(bidirectional virtual link)Service(Attaching services to segment) 3.)service : entity- services on a connectivity path. example : users can define a customized routing policy.

4). segment: To specify the connectivity path between two groups, -defined by a 3- tuple: {g1,g2,svc} -g1andg2are the endpoint groups -svcis the requested network service(s)

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5).virtnet: A virtual network is a logical topology containing groups, segments, services. -It is represented byVN= {G,S} -Gis a set of endpoint groups -Sis a set of segments defined onG. -Each segment inSis an edge defined by two endpoint groups {g1,g2 E G} and annotated with a specified service svc.17

Using these entities, users can construct a variety of connectivity topologies among VMs belonging to different applications.

Typical enterprise web service applications have a three- tier topology that consists of a 1).web server tier 2).application server tier 3).database tier. The communication between different tiers often has different service requirements. Ex: restricted communication between tiers using firewall.18

Figure shows an example for amulti-tierweb application with six VMs grouped into tiers with segments connecting them. The segments have been defined with various services such as middlebox traversal or scoped broadcasting. This model can be used to flexibly construct topologies for many different types of applications.19 Meridian Rest APIs: Floodlight exposes its services to applications using REST APIs in which applications use standard HTTP requests to send or receive JavaScript Object Notation (JSON) formatted data.

Meridian virtual net- work functionality is implemented in a separate Floodlight module that provides commands for creating, deleting, configuring, and updating individual 1)instances (e.g., a specific group or segment). 2)collections (e.g., the set of all segments in a virtual network) of network entities using corresponding URLs.Instance (key ,value).Post to create instance.Put to modify instance.Adding field to instance add (key, value) pair.Meridian commands to validate, install and uninstall virtual network entities.

20Orchestrating the Deployment of network services in MeridianPrimary components in meridians orchestration layer are the planner and deployer modules that specify and deploy network tasks.Meridian planner design : 1).Meridian implements Network services one or more plans. Plans are executed to perform the task. ex: client appPut oprtnVirtual networkValidate / Install it2.)Planner module functions as Scheduler.

21Planner ModulePlansPosted(to be executed)3.)Pool of threads for Scheduling PlansIt contains intelligence to complete the task4.) A plan can start an other plan just posting them for planner.5.) Plans can be executed in parallel .This helps in configuring switches in parallel rather than one at a time.

6.) plan1 plan2.

7.)Composability of plans continually grow set of available plans.8.)This approach is in contrast to providing a single monolithic orchestrator module that contains a single optimization program that provides all the services difficult to extend . startReply22Combining simple plans into more sophisticated plans led us to categorizing plans into two types

This provides a level of separation and flexibility.High and low level plans can be extended.Time based schedulingHigh level plans 1). They work well with meridian service model instances such as virutal ntws,grps,endpts.2).ex: they may compute set of paths.

Low level plans1). They perform low level actions and work with existing ntw objects.2).ex: they may generate associated OpenFlow rules for those paths from higher plans.23Deploying plans in the networkThe planner manages the execution and state of Meridian plans. Specifically, it processes a number of methods that are part of each plan as described below:validate() : 1).error checks to determine if installation of the plan is likely to succeed. 2).creates the list of network commands (e.g., OpenFlow rules). install(): installs the model into the physical network .

undo(): reverses the install operations per- formed by theinstall().

resume(),suspend(): resumes and suspends execution of the plan24Meridian virtual networks with OpenFlowGiven a virtual network topology defined .Meridian realizes each

OpenFlow rulesinstalling Implementing various routing policies SERVICES on the segment (ex:shortest path routing)

To implement a given segment {g1,g2,svc} 1) first locate the attachment points of each endpoint in g1 and g2 using meridians topology service . 2) Than for each pair of {ep1,ep2,ep1 -> g1,ep2 ->g2} setup routing between ep1 and ep2 using policies defined in SVC structure

Support25Major challenge : To update dynamic updates to Virtual network topology ex: 1)adding /removing segment. 2)adding ep1 to existing grp. 3)Changing svc for a segment.

So Meridian maintains control block for each virtual network.

Virtual network control block : it keeps record info of the network installation operations for virtual network during its life cycle.

It is created when each VN is defined and when overflow rules are defined.

26Cloud controller IntegrationIntegrating Meridian with cloud orchestration platforms. Although these platforms required different approaches for integration

They demonstrate Meridians ability to offer a uniform set of service APIs to multiplehigher-layercloud provisioning systems.

Openstack integration with quantum: 1). open source cloud computing platform. 2). Three major components: compute ,network, storage. 3).Networking component: Quantum 4).Quantum : pluggable, extendable, API driven architecture.

275).It is part of cloud OS which manages and creates network required by cloud apps.

6).Meridian developed quantum plug-in maps quantum constructs to meridian network model.

7).when quantum network is created ,a meridian virtual network is created with empty group and segment enabling all to all communication within the group.

8).than virtual network is installed.

9).quantum virtual ports endpoints added to group. 10). This allows quantum network manager component to work with Meridian using Standard APIs.

28SummaryMeridian, an SDN-based controller framework for cloud networking.A network service model for users to construct and manage logical topologies for their complex workloads.Current system is only an initial prototype.

29Future workPerformanceRecovery failed plans

30Reference[1] Openstack cloud software , http://www.openstack.org.[2] Cloud Naas: A Cloud Networking Plat- form for Enterprise Applications,Proc. ACM Symp. Cloud Computing, Oct. 2011.[3] S. Shenkeret al., The Future of Networking, and the Past of Protocols, slides at http://www.slideshare.net/martincasado/sdn-abstractions,June 2011.[4]Open Networking Foundation,Software-DefinedNet- working: The New Norm for Networks, white paper, Apr. 2012.

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