Re: [ns] Re: your mail

["Kun-chan Lan" <klan@usc.edu>]

it's still a tcl syntax error  , you should have another "expr" in the
expression

Kun-chan Lan

-----Original Message-----
From: tarik <tarik@usc.edu>
To: Haobo Yu <haoboy@isi.edu>
Cc: ns-users@mash.CS.Berkeley.EDU <ns-users@mash.CS.Berkeley.EDU>
Date: Thursday, June 15, 2000 10:27 AM
Subject: Re: [ns] Re: your mail


>Now the error is,
>
>ns: dump _o15 1: invalid command name "1-0"
>    while executing
>"expr $delay+1"
>    (procedure "dump" line 11)
>    invoked from within
>"dump _o15 1"
>
>
>On Thu, 15 Jun 2000, Haobo Yu wrote:
>
>> you should use 'set jitter ...'
>>
>> On Thu, 15 Jun 2000, tarik wrote:
>>
>> > Date: Thu, 15 Jun 2000 10:03:55 -0700 (PDT)
>> > From: tarik <tarik@usc.edu>
>> > To: ns-users@mash.CS.Berkeley.EDU
>> >
>> > Hi
>> >  I am trying to measure jitter between the two node but it gives me
>> > following error
>> > ns: dump _o15 1: can't read "jitter": no such variable
>> >     while executing
>> > "set $jitter [[expr $delay+1]-$delay]"
>> >     (procedure "dump" line 11)
>> >     invoked from within
>> > "dump _o15 1"
>> >
>> > My script is
>> >
>> > #set ns [new Simulator]
>> > set n0 [$ns node]
>> > set n1 [$ns node]
>> > $ns duplex-link $n0 $n1 5Mb 2ms DropTail
>> > ## Set up BSD Tahoe TCP connection in opposite directions.
>> > set src1 [$ns create-connection TCP $n0 TCPSink $n1 1]
>> > set src2 [$ns create-connection TCP $n1 TCPSink $n0 2]
>> > # Create ftp sources at the each node
>> > set ftp1 [$src1 attach-app FTP]
>> > set ftp2 [$src2 attach-app FTP]
>> > # Start up the first ftp at the time 0 and
>> > # the second ftp staggered 1 second later
>> > #$ns at 0.0 "$ftp1 start"
>> > $ns at 1.0 "$ftp2 start"
>> > ## Create a trace and arrange for all link
>> > # events to be dumped to "out.tr"
>> > #set tf [open out.tr w]
>> > $ns trace-queue $n0 $n1 $tf
>> > set qmon [$ns monitor-queue $n0 $n1 ""]
>> > set integ [$qmon get-bytes-integrator]
>> > ## Dump the queueing delay on the n0->n1 link
>> > # to stdout every second of simulation time.
>> > #proc dump { link interval } {
>> > global ns integ
>> > #global ns temp
>> > $ns at [expr [$ns now] + $interval] "dump $link $interval"
>> > set delay [expr 8*[$integ set sum_] / [[$link link] set
>> > bandwidth_]]
>> > #set $temp delay
>> > set $jitter [[expr $delay+1]-$delay]
>> > puts "[$ns now] jitter=$jitter"
>> > }
>> > $ns at 0.0 "dump [$ns link $n0 $n1] 1"
>> > ## run the simulation for 20 simulated seconds
>> > #$ns at 15.0 "$ns halt; exit 0"
>> > $ns run
>> >
>> > Would you please what is  wrong here?
>> >
>> > Thank!
>> >
>> > KAt
>> >
>> >
>>
>