Northbound application development in SDN controllers - An APIs and SDK Perspective

SDN is the one of the emerging networking technology which has gained lot of popularity in networking domain.

SDN is the software defined networking which is trying to create/manage network through software. SDN is trying to centralize brain of network into controller applications (i.e. SDN controllers).

Even SDN makes you virtualize all the network and their networking functions through Network virtualization and Network function virtualization techniques.

SDN controller, being brain of network, manages the network switches/routers by sending intelligent rules on them through southbound APIs and allows vendor-specific/domain-specific/function-specific applications to run over with SDN controller via northbound APIs.

There are lot many networking vendors who are working on SDN at fast rate and launching their SDN controller in market.

But, SDN is not getting adopted at fast rate among network operators, service providers, network application developers, etc. To accelerate this adoption, vendors of SDN controller are exposing northbound API set to create development environment among networking community so that more and more application can be developed over such SDN controller and more use-cases of SDN can be opened up.

Few vendors have shared their SDN SDK also for rapid development of applications over their SDN controllers to gain their strong existence and popularity in SDN world.

In this blog, focus has been on research of SDKs for SDN. Research on which SDN controller vendor share SDK, what SDN SDK should contain what networking use-cases/functions can be achieved by SDN SDK.

Below is the list of SDN controllers which are researched for finding their support for APIs/SDK.

SDN Controllers	Does it support Openflow?	Does it expose Northbound APIs?	Does it share any SDK?	Is SDK Open?	Language Used for APIs/SDK
HP VAN Controller	Yes	Yes	Yes. HP SDN DeveloperKit	Open	REST and Java
Juniper Contrail	No	Yes	Yes. Junos Space SDK	Open	REST
Big Switch	Yes	Yes	No	NA	REST
Floodlight	Yes	Yes	No. But, Provides many applications in java modules	NA	REST
Ryu	Yes	Yes	No. But, It provides framework to develop SDN apps.	NA	Python
IBM Programmable Flow	Yes	Yes	No	NA	REST
NCL - Hinemos and VNC	Yes	Yes	No	NA	JAVA
Cisco APIC	Yes	Yes	No	NA	REST
Cisco XNC	Yes	Yes	Yes. Cisco Open Network Environment Platform Kit	Open	JAVA/REST
Nicira/VmWare NVP	Yes	Yes	Yes	Open	REST
Nuage VSC	Yes	Yes	No	NA	REST
Plexxi Control	No	It has 2 different API: Workload Affinity API, Network Orchestration API	No	NA	REST
Sanctum's Jupiter	Yes	No information	Yes	Closed	No information
PLVision kuFlow	Yes	It is openflow driver for SDN controllers and it is available as library.	No	NA	Python, C++
Sandvine SDE		No, But it gives you PCRF GUI to design services	No	NA	NA
Active Broadband Network's BNG	Yes	Yes. It provides web services API and message queues	No	NA	No information
NetSocket vFlow	No	Yes	No	NA	No information
Metaswitch Perimeta SBC	No	Yes	No	NA	No information
Italtel SBC	No	No	No	NA	NA

Next table talks about what should SDN SDK contain and whether these SDK contents are available in existing SDN SDKs.

SDK Contents	HP VAN SDK	Junos Space SDK	Cisco XNC OnePK SDK
GUI CLI	SDN Controller Console which is web based GUI.	Yes, provide GUI plugin for Eclipse IDE	Provides API set only.
Templates	Yes	Provides REST APIs for Config Template Management	No
Schema files (WSDL, XSD)	Supports XSD schema files	Supports generation of schema (XSD) from DTO definitions using ANT scripts.	No
Sample programs	Yes, it provides some built-in apps: Device Node Manager, Link Discovery, Topology Manager, Topology viewer, Path daemon, Path daignostics	Yes. For example, HelloSpace, WorldCities, oogleMashupApp	Yes. For example, HelloElement, HelloNetwork, SyslogMonitor
Higher order models	Yes. SDK provides models and works on MVC (Model-view-controller) architecture to develop applications.	Supports 3 application models: 1) Complete Junos Space Application. This application model contains all 3: UI + web services + business logic. 2) Web Service Junos Space Application. This application model contains: web services + business logic. 3) UI Only Junos Space Application. This application model contains only: UI app. Business logic is realized by EJB packages (i.e. server side components).	No
API Libraries	Yes. The Controller REST API is distributed across 3 distinct namespaces: (1) core (/sdn/v2.0), (2) openflow (/sdn/v2.0/of), (3) network services (/sdn/v2.0/net). Each namespace has its own JSON schema. (1) Core namespace: The core APIs provide general manageability of the controller, such as configuration, health monitoring, teaming, alerts, audit logs, support logs, etc. (2) Openflow namespace: The openflow APIs provide Openflow functionalities of the controller, including both read-only operations (such as port statistics) and modification operations (such as flowmod). The same REST API can be used on both Openflow 1.0 and Openflow 1.3 devices. However, only certain APIs (such as meters) are available when speaking to an Openflow 1.3 device, because the functionality is only available for Openflow 1.3 devices. (3) Network services namespace: The network services APIs provide basic network knowledge such as network topology information and network diagnostics.	Yes. It provides REST APIs for below services: Application Management, Audit Log Management, Configuration File Management, Configuration Management, Configuration Template Management, Debug Log Management, Device Image Management, Device Management, Fault and Performance, Info Service, Inventory Management, Job Management, Script Management, Tag Management, User Management, Well Known Service	Yes. It has various services: 1) Policy service set: allows applications to configure several features of the forwarding path, including filtering, ACLs, and QoS. 2) Routing service set: provides read access to the routing information base (RIB) and enables a developer to safely modify the routing/switching logic of the network element. 3) Element service set: consists of APIs to get and set network device and interface properties, state, and statistics. 4) discovery service set provides a mechanism for an application to discover remote or local network elements, network topology, and the network elements providing onePK services.
Binaries: installation and configuration	Yes. Configuration is done through metatype.xml and maven's pom/xml	Yes. This SDK is available as installer and provides various APIs for configuration management.	Yes
Emulator/Simulator for test and validation	Yes	Simulators, virtual machine included with the developer environment.	No
Quick start and programming guide	Yes. It provides following guides: HP VAN SDN Controller License Registration and Activation Guide, HP VAN SDN Controller Installation Guide, HP VAN SDN Controller Administrator Guide, HP VAN SDN Controller Programmer's Guide, HP VAN SDN Controller REST APIs, HP VAN SDN Controller Release Notes, HP VAN SDN Controller Open Source and Third-Party Software License Agreements	Yes. It provides: Junos Space SDK Release Notes, Junos Space API Reference Guide, Junos Space Application Developer Guide, Device Simulator Guide, Junos Space SDK Installation Guide for Windows/Linux/Mac	Yes
Authentication	Yes. HP VAN SDN controller REST APIs are secured via token based authentication scheme. Openstack keystone is used to provide token based authentication.	It is not at API level. It is at user level. Because Junos Space implements a single sign-on authentication scheme, the user name and password credentials you use to log into Junos Space also validate your use of OpenNMS. No separate authentication is needed.	Yes. It uses TLS protocol to authenticate application before accessing cisco network element and also need Cisco network element to enable OnePK and TLS before any communication with apps.
Backup and restore	Yes. A controller backup takes a snapshot of the controller state, and includes the following in a single file: Controller databases, License compliance history and metrics log data, In a teaming environment, the teaming configuration, User repository folder (for user-installed applications), Controller configuration folder	No	No
Logging support	Yes. Audit log and support logs are provided.	Yes. It provides REST APIs for audit and debug log mangement.	Yes

Next table talks about what should be use-cases which can be achieved using SDN SDK and whether these networking functions support is available in existing SDN SDKs.

SDK Categories	HP VAN SDK	Junos Space SDK	Cisco XNC OnePK SDK
Network Virtualization	This is done by the controller itself.	Yes	No. Not yet supported.
Appliance virtualization	Yes	Yes	Yes with respect to Firewall.
Service Assurance and Service Differentiation	Yes	Yes, it provides policy and QoS management.	Yes. It provides services for QoS and policy control.
Cloud-Ops	Yes	Yes	No
Legacy Control	No	Yes	Yes
Network provisioning	Yes	Yes	Yes
Network management	Yes	Yes	Yes
Network Security	Yes	Yes	Yes
Network Troubleshooting	No	Yes	Yes

This research over SDK for SDN may help in choosing available SDN SDK and it may also provide pointers to start development for any SDN SDK from the scratch.

References

5998-4920_HP_VAN_SDN_Controller_Programming_Guide.pdf
5998-4919_HP_VAN_SDN_Controller_Admin_Guide.pdf
MTOSI ADAPTER USING JUNOS SPACE SDK PDF
Junos_Space_SDK_13.1_Release_Notes.pdf
Junos_Space_SDK_13.1_Release_Notes.pdf
http://www.juniper.net/techpubs/en_US/junos-space-sdk/13.1/apiref/com.juniper.junos_space.sdk.help/Services.html
http://developer.juniper.net/shared/jdn/html/browser-help-13.3/com.juniper.junos_space.sdk.help/html/guides/appdevguide/websvcsproj.html
http://www.juniper.net/techpubs/en_US/junos-space-sdk/13.1/apiref/com.juniper.junos_space.sdk.help/Services.html
Junos_Space_SDK_13.1_Release_Notes.pdf
MTOSI ADAPTER USING JUNOS SPACE SDK PDF
Junos_Space_SDK_13.1_Release_Notes.pdf
Junos Space Virtual Control app is for managing virtual network.
JunosSpaceSDK_DataSheet.pdf
https://juniper.mwnewsroom.com/manual-releases/2009/Juniper-Launches-Open-Software-Platform-to-Acceler
http://trinetprimasolusi.blogspot.in/2011/01/junos-sdk-enables-developers-to.html
http://www.juniper.net/us/en/local/pdf/datasheets/1000297-en.pdf
https://communities.cisco.com/docs/DOC-53411#jive_content_id_Is_there_an_onePK_plugin_for_OpenDaylight_
https://communities.cisco.com/docs/DOC-53411#jive_content_id_Is_there_an_onePK_plugin_for_OpenDaylight_
https://communities.cisco.com/community/developer/networking/cisco-one/onepk/blog/2014/05/15/solving-a-network-securityusability-paradox-with-cisco-onepk--ben-story
http://www.data.proidea.org.pl/plnog/11edycja/PLNOG_11_Day_2/Track_1/Krzysztof_Konkowski_Przemek_Pisarek.pdf