CHALLENGES AND CHANCES IN NETWORK

RELIABILITY

Zhaobo ZhangHuawei Technologies (USA)

2014-09-11

Outline

Background of IP Network System Reliability Causes of unreliable network Potential Directions

Background

Fast growing computers/mobile

device; ISP(regional, backbones ); IXP

Primary source of information sharing & communication

Various applications Data, voice, video

conferencing, P2P High demands

QoS, reliability, efficiency

Billions

Millions

Thousands

Hundreds

2010 Internet

The Opte Project by Barrett Lyon 

Seek to make an accurate

representation of the Internet using visual graphics.

Network System reliability

Metrics Quality of service

connectivity, E2E delay, E2E packet loss rate Network topology, service level agreement Availability = MTBF/(MTBF+MTTR)

Mean Time Between Failure, Mean Time to Repair e.g. 99.999%, means annual downtime 5.15

mins Verification

Through fault insertion test and field data

Causes of unreliable network

IP connectivity errors unstable transmission, overflow throughput, delay, network

security threat, IP resource management Network mis-configuration

network topology loop, non-optimal path, duplex mismatch, protocol unawareness

Software version/patch conflict; Logic mis-configuration; device driver

bugs, Environment

Cable/fiber cut/device damage; electrical noise, power outage Hardware: power/clock, logic aging, ram failure, soft error

Potential Direction 1

Reliability-aware hardware design Redundancy: RAM, link, NPU, board Built in smart logic

Monitor misbehavior (e.g. delay increase), early alert

Monitor traffic, Balance traffic/heat to slow aging, auto-reroute to avoid defective logic.

NPU NPU

NPU NPU

RAM

RAM

SmartOrange colors are spares

Potential Direction 2

Data mining & automated process Learn history data, provide guidance for

current/next generation design, verification introduction, debug

Data

R&D

CMO&M • Failure cases• Test & component stats

• Field-return data• Field failure

cases

• Design spec• Verification list• Fault database• FIT result• FMEA

Potential Direction 3

Big data, big network, big infrastructure, BIG power

Power consumption control Low power design Dynamic control: sleep mode, turn off SerDes, MAC

Thermal control Heat is an enemy of devices every 10 degrees Celsius of temperature rise, the

speed of all chemical reactions doubles.

Wikipedia: I know everything!Google: I have everything!

Facebook: I know everybodyInternet: Without me you all nothing!Electricity: keep talking bitches. 2% Global energy usage

Potential Direction 4

Fault tolerant control layer design/testing SDN & open flow

Decouple network control and forwarding functions

Directly programmable network control

controller performs design validation as part of configuring the network and that design validation eliminates manual errors

Business ApplicationBusiness

ApplicationBusiness Application

Network ServiceNetwork ServiceNetwork Service

Application Layer

Infrastructure Layer

SDN Control Layer

Thanks!