3 testing sip

8/20/2019 3 Testing SIP

1/33

Testing SIP

Using XML Protocol TemplatesM. RanganathanOlivier Deruelle

Doug Montgomery

Avance !et"or#ing Technologies Division$!ational Institute o% Stanars an Technology$&aithers'urg$ MD ()*++$ USA.

http,--""".ant.nist.gov-


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Introucing SIP

Peertopeer Signaling Protocol use%or IP Telephony$ /on%erencing an

Instant Messaging Introuce in 0+++

+ revisions an ( R1/s since then2

3iely eploye Microso%t RT/Server$ IM /lient$ /isco gate"ays etc.


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Introucing SIP

Te4t 'ase

unli#e 5.6(6 7Stateless8

Protocol state encoe in message

94tensi'le Many e4tensions e4ist.

/an run over unrelia'le or relia'le transports Out o% orer - roppe signaling messages.


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Simple SIP /all 1lo"

INVITE

100 Trying

180 Ringing200 OK

ACK

RTP Media Stream

BYE

OK

UAC UAS

UAS U!er Agent

Ser"er

UAC U!er Agent

C#ient

T$ere %an &e intermediate

Signa#ing n'de! (Pr')y Ser"er!

t$at *ee+ %a## !tate,-


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Protocol /haracteristics

Protocol is ro'ust an e4tensi'le, SIP #eeps enough state in the Messages to eal "ith

all these complications. /orrect implementation is tric#y.

Signaling may have to go through multiplehops.

Pro4y servers may go o"n "ithout "arning. Peers may go o"n "ithout "arning. Sessions can move "ithout prior planning. !et"or# can %ail "ithout "arning.


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SIP Testing

Loa Testing &enerate 0)):s o% simultaneous sessions.

/all 1lo" Testing Unit testing the SIP Protocol

Implementation 'y generation o%

scenarios. Primary moe o% testing uring SIP

interopera'ility test events.


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&enerating SIP Test /ases

9ntoen testing is %easi'le protocol state an causality is encoe

in the Messages-/all 1lo"s.

94haustive testing generates toomany test cases. Unerstaning implementation - protocol

comple4ities results in goo test cases.


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SIP Application Structure

A++#i%ati'n

Net.'r* (Ra. Byte!,

Par!er En%'der

Re/Re/ Re!

SIP Sta%*

T r a n ! a % t i ' n

T r a n ! a % t i ' n

T r a n ! a % t i ' n

Re/ Re!

ia#'g ia#'g

Me!!age!

E"ent!

Me!!age!

E"ent!

Me!!age!

E"ent!


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/onstructing Test /ases 1or

SIP Layer the Test /ases li#e

Applications-Stac#s are layere Message Layer$ Transaction Layer an

Dialog Layer tests

This prunes the num'er o% tests an

ma#es the tests more meaning%ul.


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SIP Messages

Protocol encoes all the state it nees inthe message.

5TTP-Mail ; li#e heaers an a Re


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Message Layer

5anle Incoming Re


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Message Layer

&rammar is conte4t sensitive an e>neusing A?!1

&rammar has change 'et"een R1/s &rammar is compositional @mail$ URL$ 5TTP Parser generators have trou'le "ith R1/

grammar

usually han coe parsers are use Some tools are availa'le ; antlr

5eaers are Te4t @?oy can 'e ?inary


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Transaction Layer

SIP Applications are transaction orientean usually interact irectly "ith a

transaction layer. Primary uties o% the Transaction Layer

Re


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I!=IT9 /lient Transaction

Calling

Proceeding

Completed

Terminated

Invite from TU

Invite Sent

Timer A

1xx to TU

300-699

ACK ent

300 !699

ACK ent300-699 ACK Sent

"xx to TU

Tranport #rr

"xx to TU

Timer $ fire%& Tranport #rr

Timer ' fire


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I!=IT9 Server Transaction

Proceeding

Completed

Confirmed

Terminated

Pa I()IT# to TU

I()IT# Send

&epone

I()IT# Send &epone

300-699 ACK ent

Timer I fire

0)00++ %rom TU

Transport 9rr (44 %rom TU

6))B++ %rom TU

Timer G FiresSend

ResponseA/C

Timer I fres


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Transaction Layer, /ommon

?ugs Implementations o not implement the Transaction State

Machine correctly ?ac#"ar compati'ility

In R1/ 6(B0 the 'ranch ID o% the topmost 7=ia8 heaerienti>es the Transaction R1/ (E6 use a hash over 1rom$ To$ Re


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Testing The Transaction

Layer 5o" to &enerate /overage to

e4haustively test !ee to rive TSM to ta#e each Transition %or each State.

Simulate lost messages Drop Re


18/33

Testing The Transaction

Layer Simulate timing variations

Delay Responses

&enerate out o% orer responses$ StrayMessages

Testing the State Machine


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Dialog Layer

Dialog is a peertopeer association'et"een communicating SIP enpoints

Dialogs esta'lishe 'y Dialog creating Transactions.

!ot all transactions create Dialogs.

A Transaction may 'elong to e4actly one Dialog.

SIP messages carry enough state toienti%y the Dialog irectly %rom themessage


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Dialog Layer

Manages Dialog /reation-Tearo"n Dialogs create 'y transaction completion

Manages Route Sets Test agent must test %or e4pecte Route - Recor

Route heaers in re


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Dialog Layer, /ommon

?ugs Dialogs are ienti>e 'y portions o% a

message, /allID$ 1rom$ To tags in R1/ 6(B0

/allID$ 1rom$ To aresses R1/(E6

Stac#s try to #eep 'ac#"ar

compati'ility ?ugs are %re


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Testing the Dialog Layer

Re


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/all 1lo" Testing Approach

Test the causal se


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Motivation

/ompact representation that matches theR1/

XML is hierarchical goo "ay to represent SIPprotocol a'stractions

Interopera'ility testing "ith control Typically components are teste in call Go"

scenarios Typically operating in an uncontrolle

environment Reproucing comple4 scenarios is iHcult


25/33

XML representation o% SIP

De>ne a set o% XML tags to representthe rene XML tags to e4press call Go"state machine

Input to 9vent 9ngine that can run the

call Go" &enerate variations o% the call Go" 'y

moi%ying the XML script


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Test Scripting Architecture

Ca## #'. Te!ting Pr't'%'# Tem+#ate

E"ent Engine

NISTSIP Sta%*

Ser"i%e 3n%ti'n

Net.'r*

Ser"i%e S%ri+t a %a##'3t t'

a !er"i%e 43n%ti'n at tran!iti'n

+'int! in t$e %a## 4#'.-

Ser"i%e C'ntainer

5M6 Engine 7 a"a9yt$'n

inter+reter

Unit Uner

Test


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Test Script

Pattern matching$ timer events an transitionsuse %or triggering transitions in test script.

Test script is represente 'y a set o% Transactionsthat may 'e neste "ithin a ialog.

The entire transaction state machine is e4posean e>ne using XML. Timing can 'e varie an controlle errors can 'e

create. Service coe can 'e calle "hen messages arrive$

transactions are starte$ transactions complete$ialogs are create or ialogs complete.


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XML Tags Mirror Protocol

Structure


29/33

3hy Do It

Simple$ clear e4pression o% test scenarios Protocol maps to XML script one to one

/an generate multiple scenarios 'aseon small variations %or the same call Go".

/an simulate common enpoint @UserAgent 'ehavior.

/an generate controlle errorconitions-timing variations.


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Test Log 1ile /ollection

Log >le is a iagnostic tool to help e'ugprotocol pro'lems.

Stac# generates log >les using XML %ormat. Distri'ute traces are collate at test pro4y

Trace vie"er pairs arcs 'y Transactions

Pr')y Tra%e "ie.er (a"a A++#et,

Re!+'nder UA6'%a# Tra%e

6'%a# Tra%eRMI


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=isualiFing the Trace

Java Appletcollects anvisualiFesistri'ute call

Go" trace >les. Augmente

"ith XML scriptstatein%ormation.

9na'lese'ugging callGo"s K testscripts.


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Relate "or#

TT/! testing o% SIP Proceural test cases

/an generate these %rom templates.

Using our approach Simpli>es logical esign

XML tools can 'e use %or test case esign.

$tt+:99...)-antd-ni!t-g'"9+r';9i+te#


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94tensions an 1uture

3or# O line veri>cation - /all 1lo" &eneration

&eneration o% /all Go"s 'ase on message logs =eri>cation o% traces 'ase on message logs

/ustomiFa'le test scripts User Uploaing o% Scripts

StanariFe XML representation o% the SIP protocol 94tensions to service creation

Integration "ith other istri'ute scripting technologies JXTA$ SOAP

3 testing sip

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