Agilent Technologies Troubleshooting H.323 Signaling White Paper By Stefan Pracht Product Marketing Manager Agilent Technologies Network Systems Test Division Contents Introduction Test Configuration Gate Keeper Discovery and Registration Correlation of Messages Problem Identification Call Setup Call Setup Message Correlation Problem Identification Call Setup Initial Communications and Capability Exchange Message Correlation - Master Slave Determination Capability Exchange Problem Identification Master Slave Determination Capability Exchange Establish Audio Communication Message Correlation - Establish Audio Communication Problem Identification - Establish Audio Communication Audio Transmission Collision with Reality 2 Introduction !!" ##$## %& &#%'&(!! #&##!#)*$+ &!&#)$+ ,!%&!*& !#*! %! & #%# %%!#-! !*#&& ###!!##&# !,!!%#* ,!!!!!%# #!#&!$!! #!#&% Test Configuration ,&!##!% !-!&! #!!!$+!./01! &%!#23 !!!$+#4%! !#$+##5! #%#!$+# #!! #"!+6707# !& Figure 1. - Reference Configuration 5*8 9,!#%#%#* 97#76:## 9;##!$,:", <# -#!###!!&#* $+,!!!!#%##! 3 Figure 2. H.323 Protocol Stack !##*!%! & #%#%%!#$ #%! !- !*%#&8 Figure 3. H.323 Connection and Session Setup 4 Gatekeeper Discovery and Registration -#*&# !&"</5 ,!</5!#%&!!! %&%!# ###!= ! 3!&! #! ,!%#&&$ #&/!&&#* !>!2%&! $+######,!## %!%?;=##@ $## /#*&#!-=8 Figure 4. H.225-RAS - Auto discovery and registration 5 Correlation of the Messages 3!)*$+ !! #&!!%!!,!%! !&#&!% !-! !%!8 9A$#$B"!# !%##&! 9A6$B"!#! !## Message Identification Information from previous messages Correlation Information for later messages ! " # $ %& %)*') '( ( () +, " ! # . / '( 0 ( %& () %)*') '( ( * IP address and UDP port number 1.1 Problem Identification Gatekeeper Discovery and Registration 5*%&!*!&8 9,!#& 9,!>! $! !!##*!## !5!!%8 9./0$+*&% 9$!(*&7$+/### %!& 9+""</5#*:(+ % ! 6 ,!&!*&#!$+##! C,!*#%!###!%& ,!#!&?!>! @%##%&! # ! # 6 &2!&?C3@# ?C3@&!# &2!!!# 9$! # 8 ",!&!>!2%#!$+## %# ",!&!#*!! #%&!#!%> 9$!! 8 "$*### ",!&%#</5##*# ",!&%###!*# ",!&#&#!& ",!#!&& Further Information 7##%%#!$,:",<#8 9"6! 9"6! " /#$) #%!%& $! !A<#65B$! !# #*!! &/!!#A(&65B#%# $! !!##&% !&!**##!! #/!! Call Setup Gatekeeper H.225RAS Gateway 1 Gateway 2 ARQ - Admission Request ACF - Admission Confirmation Setup Call Proceeding Call Proceeding ARQ - Admission Request H.225RAS H.225Q.931 Setup ACF - Admission Confirmation H.225Q.931 Alerting Alerting Connect Connect Figure 5. H.225-RAS - Gatekeeper Routed Call Signaling Figure 5 - H.225-RAS - Gatekeeper Routed Call Signaling 7 Call Setup Message Correlation ,!%!!&#&! %! H.225 Message Identification Information from previous messages Message Information For later message correlation 1 ') '( 0 ( '( 0 # " 1 %& ') %)*') '( ! - .2 1 0 ( '( 0 ( ! '( " " )*')! )5 + 6 #$ %&'() - 7322 - .2 1 0 ( '( 0 /) # '(5 + 6 #$ %&'() 7322 -8 " *$+%&'()- .2 , 34 % ())( '( ) ( '( 0 ( ! '( " ,) # '( "' ,) %&'()- , 34 % ())( '( ) **) ))( ,, ) '( 0 # '( " %&'()- * IP address and UDP port number for RAS or TCP port number for Q.931 messages Problem Identification Call Setup ,!%&8 /@/#># $#*! ! ,!%#%&8 9,!#&#!!2 2!!!! 9,!%##!*% 9,!&# 9,!&#!! 9$*#& ,! !!# #%#!,! ## !*#!! > 1@0,!6+# 6@0*#/#!!# A!B0*&*#!!%! <#!#&#! 8 (@<*#< #!!#%#,!<6 #! #8 91##!& ## 9C & !# 90!# 96#&># 96#&'># 96#&! 91### <6#! #8 91##!& ## 9C & !# 90!# 96#&># 96#&'># 96#&! 91### ;@6&# ,!&!!DA5B#,!# !!&!/ 6+# #6 ,!&=#$!! !5$!# !# !&%#! /!!DA%!B!!#!! &!!#&#3!! *#!=*# ! # Further Information 7##%%#!$,:",<#8 9"6! " 9"6! " 9D Initial Communications and Capability Exchange /!&%!# #""# !#!#!!&$ =%!#%!&#& !%##*! -!!%!#!=!,! !#!,!!#! ###%##!&!!! $! ##8 97*#,!#*#& *& 96%&!,!#!!&! &!%#%&!*&,!! %!&!%# * # #!!!&&##*,!& !####!%# !! &# !&&?#@ # 9 ,!!*## %&!8 Gateway 2 Gateway 1 MS D - Master-Slave Determination Master-Slave Determination MSDAck - Master-Slave Acknowledge (GW1= Master) Capability Exchange Termina l Capability Set Acknowledge MSAck - Master-Slave Acknowledge (GW2= Slav e) Terminal Capa bility Set Figure 6. H.2456 - Master slave determination capability exchange Figure - H.245 - Master and slave determination and capability exchange /!!%* C&# C&C&!"#"# $%#*!!*#!*# ##!!! *,!###*!! Message Correlation Master-Slave Determination Capability Exchange ,!%!!&#&! %! H.245 Message Identification Information from previous messages Message Information For later message correlation ,- ! '( 340.2 '( 0 %&'()* , ( 9) *$#$ 340.2 '( 0 %&'()* , ( *$#$ '( .+ 1) 9': *$#$ /*) 0 340.2 '( 0 %&'()* , ( ; *$#$ '( 9) * IP address and TCP port number 10 Problem Identification Master-Slave Determination and Capability Exchange ,!%&8 /@7"5*(?75(@#,!%##!!! #!8 9E&*75(<>*#!&" &#"#5 $%*%!& !#*%## 9$&75(<"#! *#!!&!! , 1@C&6%&!#,!%##!!! #!8 9,!&*!"%" #!!&%!#!6 ##!6#!8 "/##%& ",!&%#% *##!&6%&5 9,!&#!"%" #!!&##*!" !!"%" !! ,#!!"%" Further Information 7##%%#!$,:",<#8 9"6! // 9="6!" " " /#$$" /# $$$ Establish Audio Communication /!#*###!% !# !!%%!#%!& &!##*#,!###= ##A!B E!#*&#*###*# ;*&!#! !!,!##& !# #!##!*! !!,!!!!& #&*###!#!! $ #! !!# %!%%!#&!,! !##*#!# 11 ,!!!8 Gateway 1 Gateway 2 O pen L ogic al C hanne l O pen L o gic al C ha nne l Ac kno wle dg e O pen L ogic al C hanne l O pen L o gic al C ha nne l Ac kno wle dg e Figure 7. H.245 - Open Logical Channel Figure 7 - H.245 - Open Logical Channel Message Correlation Establish Audio Communication ,!%!!&#&! %! H.245 Message Identification Information from previous messages Message Information For later message correlation /) ;( %,)) 340.2 '( 0 %&'()* ( 12 !< 1) )* ,2 <% ) 3#< ) " )': /) ;( %,)) )( 340.2 '( 0 %&'()* ( 41'( 0 12 * IP address and TCP port number Problem Identification Establish Audio Communication ,!%&!%!!8 /@<*&>!,!!& #&'( %!,! #!>#8 9(& #*% 97!# 9$%##! 9$*#$( 97* 1@,!&#'( %*&'(!$!!! &#*!# ! &!,!&=",#! # 12 Further Information 7##%%#!$,:",<#8 9"6!8 // 9="6! = /#$$= /#$$$ Audio Transmission /!%*#%!#, #!!#8 9/###*<,+!$+###:(+% ##!&'( 9,!&!#*##*<,6+ !<,+6 +,!!#&#*#$ %##%!:& *& *#&<,6+ <,6+!$+###:(+%##! &'(/!&!<,6+ !!<,+*!55<6?5&!25@# #%!<,+#<,6+ H.323 - Collision with Reality ,!#%%&*#!! $ >#### # !%!! !$,:",<#*& & &,!!!#!%!!### :(+,6+%& *#<,+&# & #&!##! %!!#,!&%# ##! &!!#%#" $! ##!&!#%!*%## !#&!*! !### # 3!!!# % #&"%!*#!&# ;*"&% !!!&&!& #*#+&2 %!*##&%!& About the Authors Stefan Pracht 5+!+#77/,!' 05&,(** #$+ 5!%! #*/')$+%#!## #&!, *& #)$+# &# (!&!"+#6&#/ ,! !!#!###* ##*##!& #&&5!#*#%##$+& &%+F/# +>"+#F/,! 5# >(!,'#/,7 5!#1!5,# !:*&(% C&#!*& ## #* ## 13 14 Notes: 15 www.agilent.com Agilent Technologies’ Test and Measurement Support, By internet, phone or fax, get assistance with all your Test and Measurement needs. 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