Www.ist-muse.eu Performance Evaluation of the CPE WAN Management Protocol Serafeim Papastefanos NTUA.

www.ist-muse.eu

Performance Evaluation of the CPE WAN Management Protocol

Serafeim PapastefanosNTUA

www.ist-muse.euICCS / NTUA

Outline

> Introduction to CWMP

> Advantages / disadvantages of CWMP

> Performance metrics

> Improvements

> Results

> Implementation details

> Conclusions


The CPE WAN Management Protocol (TR-69)

Gaming Console

Security

VoIP Phone

OperationsDevice Management

Firmware ManagementService Management

AutoProvisioningBAR

RMA Services

Media Server

ResidentialGateway

TV & Set-Top box

Hi-Fi Audio

PC

Home NetworkPublic Network

ACS SouthboundInterface

ACS NorthboundInterface

Service ProvidersOperators

Content ProvidersApplication Providers

Customer Support Representatives

CPE WANManagement Protocol

CPE Parameters

CPE Parameters

SSL/TLS

HTTP

SOAP

RPC Methods

Inte

rnet

Sta

ndar

dsD

SL

For

umD

efin

ed

Ven

dor

Def

ine

d

TCP/IP


Advantages of CWMP

> Usage of TCP• Reliability• No problem transferring bulk data

> Passing through firewalls as HTTP traffic

> Avoidance of persistent connections

> Usage of XML• Extensibility• Lots of tools


Disadvantages of CWMP

> Usage of XML• Increased requirements in bandwidth• Increased requirements in resources

– Especially in TR069 clients which are embedded devices

> Single ACS• This may be an issue in a multi-provider environment


Performance Metrics

> Processing time• Decoding and encoding of messages• Management process• Network delay

> Memory requirements

> Bandwidth requirements

> GetParameterValues and GetParameterValuesResponse messages will be used for measurements


Improvements

> Generic parsers• DOM

– Can also be used for encoding or messages

• SAX– Encoding has to be done “by hand”

• Easy to use – more resource requirements

> Non-generic parsers• Harder to use – less resource requirements

> Compression• We reduce the bandwidth requirements but increase the

processing time.


Memory requirements

0

20

40

60

80

100

120

140

160

180

200

0 50 100 150 200# of state variables

siz

e /

KB

yte

s

GetParameterValues

GetParameterValuesDom

GetParameterValuesResponse

GetParameterValuesResponseDom


Encoding / decoding time

0

10

20

30

40

50

60

70

80

0 50 100 150 200# of state variables

tim

e / m

s

DOM timegeneric timeCompression time


Compression sizes

0

5

10

15

20

25

30

35

40

45

50

0 20 40 60 80 100 120 140 160 180 200Number of state variables

SO

AP

PD

U s

ize

(Kb

ytes

)

GetParameterValues

GetParameterValues Bulk

GetParameterValues (Compressed)

GetParameterValues Bulk(Compressed)


Time needed for management

0

0,1

0,2

0,3

0,4

0,5

0,6

0 50 100 150 200

# of state variables

tim

e / s

512/256 kbit1024/512 kbit10 Mbit512/256 kbit comp1024/512 kbit comp10 Mbit comp


Implementation details

> A mini-ITX with a 600 MHz CPU was used.

> CWMP client build in C• Intel’s IXML library used for DOM parsing• Our implementation of non-generic parser

> mallinfo() to measure the DOM tree memory requirements

> minilzo library to implement compression

> gettimeofday() used to measure time


Conclusions

> TR069 has many advantages over NETCONF and SNMP

> TR069 benefits from compression of messages, even in high network links

> Using SAX or even better non-generic parsers instead of DOM optimizes resource usage and speed

Www.ist-muse.eu Performance Evaluation of the CPE WAN Management Protocol Serafeim Papastefanos NTUA.

Documents

ntua time

ntua memory requirements

management slide

ntua implementation

tools slide

decoding time slide

ntua conclusions tr069

ntua compression sizes