LOAD BALANCING WITH SDN/NFV

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Executive Intro Slide

LOAD BALANCING WITH

SDN/NFV

Gert Grammel

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PROBLEM STATEMENT

1. Quality of Experience over a shared medium relies on flow identification and control

2. Applications have a limited capability to deal with packet re-ordering of a flow

3. Flows are not necessarily long lived

4. Data Centers are source&sink of zillions of flows

5. Infrastructure has to be built and operated to deal effectively with imbalances

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STATE OF THE ART

APPLICATIONS

• A flow is basically a sequence of packets between two applications

• Applications rely on the Internet to deliver the packets in sequence

• Protection against packet mis-ordering introduces additional delay 6 4 6 4 5 2 3 1 S odd even 5 R 3 1 2 2 3 1 6 4 5 2 3 1 S odd even 5 6 4 R 3 1 2 2 3 1 1 2 3

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STATE OF THE ART

RECEIVER SIDE

• Is packet #n lost or delayed?

• How long to wait for #n after #n+1 did arrive? • TCP/IP throughput is delay and loss sensitive • RTP is jitter, delay and loss sensitive

http://www.switch.ch/network/tools/tcp_throughput/

Conclusion:

• Since packet re-ordering in the current Internet is rare, many applications simply drop mis-ordered packets, thereby

reducing buffering&delay for a flow

TCP throughput: http://www.cablinginstall.com/articles/print/volume- 20/issue-6/features/cloud-services-hinge-on-application-performance-on-wans.html

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HOW CAN THE DC AND THE NETWORK

AVOID PACKET RE-ORDERING?

• Switching equipment needs to identify flows and route all

packets of those flows on the same facility (queues and links)

3 2 3 1 2 1 S Flow-Y Flow-X 5 4 3 2 1 2 1 4 3

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Internet Internet

HOW TO DEAL WITH FLOWS IN DATA

CENTERS?

S S S S L L L L L L L L L L L R R L L L NETWORK ADRESSING Appliance LOAD BALANCING Appliance FIREWALL Appliance VPN Appliance PARENTAL CONTROL Appliance DPI/TDF Appliance APPLICATION Appliance LOAD BALANCING Appliance WEB AWARENESS Appliance

Router CACHING &

CONTENT Appliance 1 1

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STORAGE

LOAD BALANCING (1)

WAN Internet

• Router needs to look deep in the packet to identify flows • Router does not know how

‘big’ a flow will be

• Router does not know how long a flow will live

• Router does not know what other routers decide

About Flows

Is this a good flow distribution?

But this is a bad idea This looks good

Is this still a good flow distribution?

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VIDEO

LOAD BALANCING (2)

WAN Internet

• Router needs to look deep in the packet to identify flows • Router does not know how

‘big’ a flow will be

• Router does not know how long a flow will live

• Router does not know what other routers decide

About Flows

Is this a good flow distribution? Is this still a good

flow distribution?

But this is a bad idea

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OTHER ISSUES IN IDENTIFYING FLOWS:

TUNNELING

https://en.wikipedia.org/wiki/IPv4 S Flow-Z 5 6 2 3 4 3 1 1 1 2 2 3 Encaps

• One or two flows? • How many bytes

need to be

inspected to decide?

1 1 1 2 2 3

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HOW ABOUT RINA?

• RINA has a strong hierarchy concept: Recursive encapsulation creates big flows • Nodes are not allowed to look beyond the bottom layer in search for finer flows. • If big flows are transported over smaller interfaces (e.g.LAG) they must be split-up

• either introduce reassembly buffers and dimension them carefully • Or find a way to identify (n-x)-DIF PDU flows in a (n)-DIF PDU flow

0-DIF-a1 1-DIF 0-DIF-b 0-DIF-c1 0-DIF-d 1-DIF 2-DIF

System System System System System

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SDN USE CASE TRAFFIC DISTRIBUTION

NE: Normalization Event (macro-adjustments)

Usable BW samples

NS: Normalization Sampling (aggregate bandwidth samples)

95%

5% BW

At Normalization Event:

Traffic is re-balanced based on flow information, route information and bandwidth

timeline

ABA: Auto-bandwidth adjustment (micro-adjustments)

The goal of TD is to spread load across a few Paths such that the load on each Path is roughly the same and is within given bounds

NS

ABA NE

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FUTURE: NFV SCHEDULER INCLUDING

HOSTS

Fastpass Datacenter Network, SIGCOMM’14, August 17-22,2014, Chciago, IL, USA

Arbiter / Scheduler allocates time-slots and paths based on destination and size of the packets.

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SUMMARY

LOAD BALANCING SOLVES ACTUAL NETWORK PROBLEMS SIMPLIFIED OPERATIONS  For operator and controller  Same operational procedures whether integration is actual or virtual CREATES ECOSYSTEM where best-in- class products are designed to work together as a virtual unit  From different product categories (routers, switches)  From different layers (packet and optical)  With different capability in scale and feature MIGRATION TO CONTROLLER-BASED NETWORK  Allows two or more heterogeneous network elements to be managed as a single virtual network element  Controller function may be separate or embedded in one of the network elements

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Big Concept Slide