sdn interfaces and performance analysis of sdn components · application-awareness: better...

Steffen Gebert, David Hock, Michael Jarschel, Thomas Zinner, Phuoc Tran-Gia

www3.informatik.uni-wuerzburg.de

Institute of Computer Science Department of Distributed Systems

Prof. Dr.-Ing. P. Tran-Gia

SDN Interfaces and Performance Analysis of SDN components

2 SDN Interfaces and Performance Analysis of SDN Components Steffen Gebert

Agenda

u  „A Compass for SDN“ §  Interfaces §  Features §  Use cases

u  Performance of the SDN architecture §  Data Plane Performance §  Control Plane Performance §  Analytical Model

u  Network Functions Virtualization §  Placement in a Mobile Network §  Performance Evaluation a virtualized network function


A COMPASS FOR SDN

IEEE Communications Magazine, June 2014 M. Jarschel, T. Zinner, T. Hossfeld, P. Tran-Gia, W. Kellerer


Interfaces…

Switch

Switch

SDN WAN

SDN Network Control Plane

Switch

Network Control Module

Southbound API

Network Control Module

Applica8on Control Plane

Applica8on Control Interface

Northbound API

Applica8on Control Module



Westbound API

Hypervisor vSwitch

Cloud


Hypervisor vSwitch

Hypervisor vSwitch

Eastbound API

User

Legacy Network Control Plane

Legacy WAN

User

User


….Features… u  Programmability

§  Principle and also key feature of SDN §  Opens control plane to innovation and enables customization

u  Protocol independence §  Compatibility with other networking technologies & protocols §  Enables technology migration and application-tailored network stacks

u  Ability to dynamically modify network parameters §  Active modification of network parameters close to real time §  Enables fast and flexible adaptation in changing environments

u  Granularity §  Control of traffic flows on varying aggregate level and protocol layers §  Ensures scalability of the control plane to work on different levels

u  Elasticity

§  Describes the ability of the SDN control plane to scale up and down §  Enables the control plane to react to variations in traffic mix and volume.


…and Use Cases

u  Cloud Orchestration: Provisioning and operation of cloud applications requires integrated management of network and cloud framework

u  Load Balancing: Integration of load balancing within network forwarding elements operating on different granularities

u  Routing: Centralized control plane in SDN provides ample opportunities for

routing protocol adaptation

u  Monitoring and Measurement: Ability to perform certain network monitoring operations and measurements without additional overhead

u  Network Management: Automatic adaptation of network policies based on monitoring information

u  Application-Awareness: Better cross-layer optimization between applications and network capabilities


Use-Cases and Interfaces

Interface

Use Case

Southbound Interface

Northbound Interface

Eastbound Interface

Westbound Interface

Cloud Orchestration

✔ ✔ X X

Load Balancing ✔ ✔ X ✔

Routing ✔ X ✔ ✔

Monitoring and Measurement

✔ ✔ ✔ ✔

Network Management X ✔ ✔ X

Application-Awareness X ✔ X X


EXAMPLE: CLOUD ORCHESTRATION


Migration – Intra DC


Energy Op?mizer

QoE Op?mizer

Switch

VM3

VM2

VM1

Switch

Switch

Cloud Mgmt. Module



Switch

VM3

VM2 VM1

Switch

Switch


Energy Op?mizer

QoE Op?mizer

Cloud Mgmt. Module


Migration – Inter DC


Energy Op?mizer

QoE Op?mizer

VM3

VM2

VM1

Cloud Mgmt. Module

Switch Switch


Energy Op?mizer

QoE Op?mizer

Cloud Mgmt. Module

Switch Switch


Network Control

WAN Op?mizer

Network Mgmt. Module

Switch Switch

Switch

Switch




Energy Op?mizer

QoE Op?mizer

VM3

VM2

Cloud Mgmt. Module

Switch Switch


Energy Op?mizer

QoE Op?mizer

Cloud Mgmt. Module

Switch Switch


Network Control

WAN Op?mizer

Network Mgmt. Module

Switch Switch

Switch

Switch

VM1



u  Problems: §  Variability of traffic §  Application requirements §  Interaction between controllers §  etc…

B4: Software-Defined WAN (Google, ACM Sigcomm 2013)


Current Research Topics

u  Performance evaluation of the SDN architecture u  (Controller placement and controller architectures) u  (SDN-based application and network interaction) u  NFV – placement and performance


PERFORMANCE OF THE SDN ARCHITECTURE


Performance of the SDN Architecture

u  Performance of the data plane u  Performance analysis of SDN Controller u  Modeling and performance evaluation of the SDN architecture


Performance of the Data Plane

u  Analysis of throughput and processing delays of OpenFlow enabled forwarding devices §  Open vSwitch §  NetFPGA §  Pronto OpenFlow-enabled switch

u  Testbed to measure data plane performance of devices §  Link rate of 1Gbit/s §  Endace DAG card to

capture traffic


Results – Number of Forwarding Rules

u  Processing delay for a nearly empty (one rule) and a full flow table

u  Significant impact of payload length on processing delays u  High impact of flow table entries on NetFPGA performance


Results – Forwarding to Controller

u  Impact on processing delays by forwarding all packets to NOX controller

u  Massive packet loss between 95% and 99% u  Significantly increased processing times u  Controller acts as bottleneck in this scenario


Performance Analysis of SDN Controllers

u  Analysis of KPIs of SDN controller software in realistic environments §  Throughput, latency, CPU & RAM, IAT,… §  Holistic framework for different OpenFlow versions

u  Implementation of OFCProbe §  Emulates data plane message and resulting

control plane traffic

u  Features §  Generated control messages per switch §  Topology emulation and PCAP file playback §  Incoming data packets can be arbitrarily distributed


Outstanding Packets: Floodlight

u  Floodlight: Uniform handling of particular switches - consistent behavior u  Nox: Non-uniform handling – “waves” detectable


Performance Evaluation of SDN

u  Investigation of the performance of the SDN architecture for changing parameters §  Modeling of control and data plane §  System scalability and limitations of the concept

u  Evaluations using analytical modeling and simulations §  Input parameters based on measurements with real hardware §  Verification of analytical results with simulations

u  Simulation of OpenFlow §  OpenFlow implementation for OMNeT++: OFOmnet §  Code available at https://github.com/lsinfo3/ofomnet


Simple Model of SDN

u  Abstraction as feedback-oriented queuing system model §  Forward queueing system of type M/GI/1 §  Feedback queueing system M/GI/1-S


Results for Different Forwarding Probabilities

u  Impact of different forwarding probabilities on the average packet sojourn time

u  Mean sojourn time increases for increasing controller load and for increasing forwarding probability


SDN Performance: Summary

u  Performance analysis of SDN architecture and SDN control plane §  Controller analysis using OFCProbe §  Performance evaluation of the architecture using models

u  Main results of the current investigations §  Diverse behavior of software control planes, e.g., Floodlight

outperforms NOX in terms of throughput and fairness §  Scalability mainly depends on control plane

u  Other issues: §  Investigation of different topologies and software controllers §  Integration and investigation of OpenFlow 1.3 §  Impact of messages via Northbound interface §  Extension of the analytical models


NFV – PLACEMENT AND PERFORMANCE


Network Functions Virtualization


NFV in Mobile Networks

u  Problem: Mobile Core consists of numerous expensive, proprietary, overdimensioned middle boxes.

u  Idea: §  Move network function into software (NFV) §  Run and orchestrate it in cloud

u  Advantages: §  Shorter release cycles §  Elasticity §  Flexibility

u  Showcase: Dynamic instantiation of Serving Gateways (SGW) in case of increased resource usage caused by “mega events”

Photo: Ericsson


Legacy SDN

Legacy SDN SDN

SDN Controller

Network Management

Security Rules

External network

A1

A2

VNF 1

IT client IT client

Use case : Network Function

Cloud Infrastructure with virtualized appliances and virtualized network functions

Cloud Controller

Smartphone

Cloud NFV & SDN


NFV: Placement and Performance of VNFs

u  Performance analysis of virtualized network functions u  Placement of virtualized network functions (VNFs)


MEGA EVENT USE CASE SDNA – Software Defined NFV Application


Mobile Network Infrastructure

Event Home Ben

NE+

Operator Control Center

NUC* CAM*

* CAM Cloud Application Manager NUC Network Utilization Control POCO Pareto-Optimal Resilient Controller SGW Serving Gateway

Ann

POCO*

SGW

Data center

SGW Controller

SGW App


Increased Resource Requirements for Mega Events

Event Area Ann

Ben

Home Area

Ben

Home Area

Event Area Ann


Planning Infrastructure on Demand


Flexible Reuse of Existing Infrastructure

3. Security check

1. Deploy SGW App and Controller à CAM

2. Program virtual GW à SDN+CAM

Event Home Ben

SGW

Operator Control Center

NUC* CAM*

* CAM Cloud Application Manager NUC Network Utilization Control POCO Pareto-Optimal Resilient Controller SGW Serving Gateway

POCO*

SGW

SGW Controller

SGW App

Ann

Video call

Data center

SGW Controller

SGW App

Video call


Virtualized Network Functions in Operator Cloud

Ø  Scalability

Ø  Redundancy

Ø  Flexibility

Ø  Open Source platform

CAM

NUC


PERFORMANCE OF VIRTUALIZED NETWORK FUNCTIONS


Performance of Virtualized Network Functions

u  Impact of softwarization on performance of network functions §  Impact on typical KPIs, i.e., delay, throughput §  Influence of dynamic function placement

u  Categorization and Modeling of VNFs §  By resource demands: CPU-intense, network-intense, etc. §  By ability to scale out: scale out delay, state-sync, etc. §  Identification and investigation of characteristic VNFs §  Analysis of the influence of the virtualization platform


Performance of a Virtualized Firewall

u  Comparison of Cisco ASA/ASAv in a dedicated testbed §  Cooperation with the computing center of UniWü

u  Measurement-based comparison of virtualized and hardware Cisco ASA Firewall §  Data plane performance (throughput, connection setup) §  Configuration and monitoring via REST API

u  Entities under investigation: §  ASA Service Module (Hardware) §  ASAv on vmware / KVM

External network

Internal network

Firewall Module


Summary

u  SDN interfaces are key to integration and better user experience §  Interaction with legacy infrastructure and cloud controller §  Tailored handling of traffic flows or aggregates §  Application-aware networking ensures optimal user experience

u  SDN control plane is performance-critical for the whole network §  Measurement and simulation tools provided §  Suggestion of (simple) analytical model §  Optimal controller placement and hierarchy under investigation

u  Network Functions Virtualisation (NFV) as logical step, supported by SDN §  Open issues regarding performance of pure software implementations,

interfaces, placement, operations, monitoring, ... §  Benefit: Flexibility of the network as we know it from software §  Mobile network operators are planning rollout of virtualized EPC

sdn interfaces and performance analysis of sdn components · application-awareness: better...

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