Abstract

This project implements a new SBI for ONOS and allows new deployment use-cases. The main goal is to support the L3 multi-tenants isolation in a cloud network and routing system in a simple, a stable and a scalable way. In fact, a BGP/MPLS IP VPNs solution can be used and extended via the XMPP protocol to provide a Virtual Network service to end-systems (compute nodes or virtual machines). These compute nodes may host end-user applications and can provide network services.

Team

  • Project owner: Abdulhalim Dandoush, ESME Sudria engineering school, France

contact: abdulhalim.dandoush at esme.fr


  • Main developer: Tomasz Osinski, Orange Labs & Warsaw University of Technology, Warsaw, Poland

Contact: tomasz.osinski2@orange.com, osinstom@gmail.com


  • Mentor: Andrea Campanella, ONF engineer,CA, USA

     Contact: andrea at opennetworking.org

Status

 


Problem space

Why are we doing this?

Problem statement

The BGP protocol is widely used in the networks and recently it has received a lot of attention in the context of Routing solution for Large-Scale Data Center [1]. However, it is not widely deployed in hosts/hypervisors. The IETF draft [1] discusses how the control plane for BGP IP VPNs [RFC4364] can be used and extended via the XMPP protocol to provide a solution for large-scale data centers that meets some key requirements, e.g., accommodating application bandwidth and latency. This solution provides an IP service to end-system virtual interfaces and improves network stability and scalability, as a result of confining L2 broadcast domains and isolating the different tenants at L3 level. The XMPP protocol (with Publish/Subscribe extension) is used in this solution to distribute routing information over the network. However, the ONOS controller does not support XMPP implementation as SBI, thus the usage of ONOS in the described framework is not possible so far. Moreover, as the XMPP protocol is highly extensible it may be used in various applications, so it may be used as general-purpose message bus in SDN/Cloud network.

Impact of this problem

The implementation of XMPP as SBI will allow the deployment of ONOS in new use cases and the consideration of the architecture described in [2] as the networking solution for the OpenStack-based clouds. It will provide L3VPN or EVPN network isolation between tenants. Moreover, the XMPP is easily extensible and may be used to design future network configuration strategies.

How do we judge success?

The goal of the project is to provide XMPP protocol support for ONOS controller. The XMPP implements the  IETF draft “BGP-signaled End System IP VPNs” architecture and then ONOS can communicate with any virtualization hypervisor with a vRouter support as the case of Compute Nodes that have a vRouter support at the KVM hypervisor level proposed by Juniper via the OpenContrail project. The validation of all control plane scenarios defined in [2] is required. The first implementation will support XEP0060 (Publish/Subscribe) described in [3]. Moreover, the implementation will be designed to provide extensibility of XMPP, so the new XMPP extensions may be implemented by new OSGi module in Protocols layer.



Ready to make it

What are we doing?

The XMPP protocol is XML-based data exchange protocol. The main feature of XMPP is extensibility and payload-agnosticism. The XMPP Core as explained in the RFC6120 [4] describes the basics of XMPP, while the communication model is defined in XEP (XMPP Extension Protocol) specifications. We have designed the XMPP protocol implementation in the extensible manner, so the core XMPP implementation may be extended by the new XEPs seamlessly.  

The project will deliver the extensible implementation architecture of XMPP for ONOS. Moreover, the PoC of architecture [2] will be presented as the use case (Intra-DC L3VPN/EVPN) for XMPP implementation.

Why will a customer want this?

The project results will provide one more protocol to build SDN control plane by using XMPP protocol. It may drive a new innovations in the area of SDN by applying XMPP protocol to new use cases. The usage of XMPP allows to build the novel data center multi-tenancy technology as an alternative to classical OpenStack mechanism or ONOS SONA.

Perspective

Integrate the work with the Gluon project


Implementation details and user guide

This section provides an overview on the XMPP protocol implementation in ONOS. In order to understand XMPP-specific terminology please refer to https://xmpp.org/rfcs/rfc6120.html#streams-fundamentals

Model architecture and abstraction

The eXtensible Messaging and Presence Protocol (XMPP) is a general-purpose, universal protocol. The main feature of XMPP is its extensibility and payload-agnosticism, what makes XMPP very powerful and high-level protocol that may carry various information such as routing, configuration or monitoring.

The main assumption of XMPP protocol implementation design for ONOS was to provide extensibility of XMPP protocol, as Publish/Subscribe extension is not the only use case for XMPP. The current implementation allows to re-use the core implementation of basic XMPP mechanisms (such as stream establishment or handling of basic XML stanzas) and based on that develop the new XEPs that are needed for particular use case. Our implementation design of XMPP functionality for ONOS controller is depicted below. It is composed of two main parts: the XMPP Providers and Route Server application. The XMPP Providers implement XMPP SBI, while Route Server application realizes BGP-VPN system using data abstractions provided by XMPP Providers.The XMPP Providers translates XMPP objects into three ONOS abstractions: Device, Route and Flow.



XMPP Providers

We have made decision to divide Protocols layer into two components: XMPP Controller and XMPP PubSub Controller. Such a decision is due to the nature of XMPP protocol. XMPP may be extended by new XEPs, so that we provide a possibility to build new extensions in future without modyfing already existing implementation. The implementation of core XMPP is provided by XMPP Controller, which is responsible for:

Based on core XMPP implementation we have developed XMPP PubSub Controller implementing Publish/Subscribe (XEP-0060) extension. The XMPP PubSub Controller listens to IQ stanzas and:

The XMPP PubSub Controller produces notifications, that can be handled by higher layers. The Providers layer includes the XMPP Device Provider and XMPP EVPN Provider. The XMPP Device Provider listens to notification from XMPP Controller and creates a new Device object, when a XMPP session is established. The XMPP EVPN Provider is implemented based on XMPP PubSub Controller. It listens to XMPP PubSub events (SUBSCRIBE, UNSUBSCRIBE, PUBLISH, RETRACT). These messages are handled by Route Provider, which translates PubSub attributes and payload into BGP EVPN constructs, which are provided by RouteService subsystem. The PubSub messages are handled, so that:

The events generated by RouteService are handled by Route Server application. When new event is handled, the Route Server may install a Flow, which is constructed based on BGP Route object and translated into XMPP Event Notification (Message stanza). The Flow installation request is handled by XMPP Flow Provider, which generates XMPP Message stanza based on the Flow object and sends it to the appropriate devices.

Key implementation pieces of code

The code implementing XMPP protocol is located in Protocols and Providers layers. The source code of XMPP Core controller is already integrated with ONOS master branch. The source code of XMPP PubSub Controller, EVPN Provider and Route Server is available at https://github.com/osinstom/onos/tree/xmpp-bgpvpn.

The XMPP implementation follows ONOS code convention. The folder structure of Protocols layer's modules includes “api” subfolder  containing interface definitions and “ctl” containing implementation classes. The implementation uses also several external libraries:

Interfaces and classes

Setting up Virtual Lab

As the main use case for XMPP implementation in ONOS, the XMPP-based BGP-signaled End-System IP/VPNs architecture has been implemented. This architecture in general consists of centralized control plane entity called End-System Route Server and distributed vRouters (or VPN Forwarders). For the experiments purposes the XMPP-enabled vRouter emulator (based on Mininet and Open vSwitch) has been implemented (https://github.com/osinstom/vrouter-client-py). It provides basic functionalities of VPN Forwarder such as XMPP communication with server and VXLAN encapsulation.  We have also developed the Route Server application for ONOS providing VPN membership management and BGP route distribution logic, which are the basic functionality of End-System Route Server.

In order to run a simple demo you have to set tup three VMs. We use VirtualBox to provide three VMs on local laptop. It's preferred to create two separate networks between VMs (we use VBox Host-Only Adapter networks):  management network for control plane operations and data network for connecting emulated compute nodes. The lab architecture is presented below:



Controller node

Before running the XMPP clients you should run ONOS controller:

Compute nodes

On every compute node there should be vRouter emulator deployed. The vRouter emulator is based on Mininet and allows to emulate data center compute node running VMs (Mininet hosts). The vRouter has been implemented for the L3VPN architecture testing purposes. To configure compute nodes follow the steps below:

Demo and Results

A simple demo using vRouter emulator has been developed already. The PoC presents XMPP-based BGP-signaled End System IP VPN using ONOS as a control plane.

The short demo video is available at:

https://drive.google.com/file/d/1Ru1tb_65kI7nnVpK8RLoFDTvc1iT77xy/view?usp=sharing

Presentation with the Technical Steering Team:


Gerrit reviews:

https://gerrit.onosproject.org/#/c/16781/


References:

[1] https://tools.ietf.org/html/rfc7938

[2] https://datatracker.ietf.org/doc/draft-ietf-l3vpn-end-system/?include_text=1

[3] https://xmpp.org/extensions/xep-0060.html

[4] RFC6120, https://xmpp.org/rfcs/rfc6120.html



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