DTMF RFC2833 lost

[fbrendel]

Net::SIP::DTMF reports lost packets when I try to send DTMF events via User-Agent: OpenScape Business telephone system that supports RFC2833 for DTMF events only.

Net::SIP::Debug

1688022804.0215 DEBUG:<50> Net::SIP::Dispatcher::Eventloop::loop[220]: call cb on fn=4 rw=0 rtp_receive
1688022804.0215 DEBUG:<50> Net::SIP::Simple::RTP::_receive_rtp[256]: received 172 bytes from RTP
1688022804.0216 DEBUG:<100> Net::SIP::Simple::RTP::_receive_rtp[285]: ch=0 payload=95/160 pt=8 xh=0 padding=0 cc=0
1688022804.0216 DEBUG:<30> Net::SIP::DTMF::__ANON__[100]: lost 1 packets (94-94)

RTP captured by Wireshark

Real-Time Transport Protocol
    [Stream setup by SDP (frame 6)]
        [Setup frame: 6]
        [Setup Method: SDP]
        [Generated Call-ID: b641850bb43beaa5]
    10.. .... = Version: RFC 1889 Version (2)
    ..0. .... = Padding: False
    ...0 .... = Extension: False
    .... 0000 = Contributing source identifiers count: 0
    0... .... = Marker: False
    Payload type: telephone-event (101)
    Sequence number: 193
    [Extended sequence number: 65729]
    Timestamp: 46400
    Synchronization Source identifier: 0xa1984e12 (2711113234)
RFC 2833 RTP Event
    Event ID: DTMF Pound # (11)
    1... .... = End of Event: True
    .0.. .... = Reserved: False
    ..00 1000 = Volume: 8
    Event Duration: 1280

Net::SIP::Simple

$UA->listen(
   init_media => $UA->rtp( 'send_recv', 'sound.wav'),
   rtp_param => [8, 160, 160/8000, 'PCMA/8000'],
   recv_bye => \$hangup_peer,
   cb_dtmf => sub { push @Events, shift;},
   dtmf_methods => 'rfc2833'
);

A test with Twinkle as SIP endpoint works fine whereby all DTMF events were recognized.
Net::SIP::VERSION is 0.835.
Perl is 5.32.1

[noxxi]

What you show is only a debug message and does not indicate any actual problems. It is perfectly normal that there might be packet loss with UDP and Twinkle likely does not even report it in the first place. It would be a problem if there is actually a loss in the transmitted information (i.e. wrong DTMF sequence) but there is no indication of such a problem in your question.

[fbrendel]

Ups, my bad.
I forgot to mention that I never get these DTMF events in @Events.

[noxxi]

In this case please provide a full packet capture (pcap file, not text or image) from what you observe with the failing code and what you observe with the working code (Twinkle) so that one can detect the differences. And also provide all information to reproduce the issue, i.e. the full code and a detailed description of the setup.

[fbrendel]

The pcap files:
net-sip.pcapng (failed)
twinkle.pcapng (works)

The code:

#!/usr/bin/perl

use strict;
use warnings;
use Net::SIP;
use Net::SIP::Debug qw( Net::SIP*=3 Registrar=1 );

my $UA = Net::SIP::Simple->new(
   from => '375',
   outgoing_proxy => '10.2.60.110:5060',
   registrar => '10.2.60.110:5060',
   domain => '10.2.60.110:5060',
   auth => [ 'xxx', 'xxx']
);
$UA->register(expires => 1800);
if($UA->error){ die $UA->error();}

my $RTPDone;
my $HangupPeer;
my $DTMFDone;
my $TimerTimeout;

my $DTMF = '';
my $DTMFCallback = sub {
   my ($Event, $Duration) = @_;
   $DTMF .= $Event;
   if($Event eq '#'){ $DTMFDone = 1;}
};

$UA->listen(
   init_media => $UA->rtp( 'send_recv', 'blindtext.wav'),
   rtp_param => [8, 160, 160/8000, 'PCMA/8000'],
   cb_rtp_done => \$RTPDone,
   recv_bye => \$HangupPeer,
   cb_dtmf => $DTMFCallback,
   ring_time => 45
);

$UA->add_timer(60, \$TimerTimeout);
$UA->loop(undef, \$RTPDone, \$HangupPeer, \$DTMFDone, \$TimerTimeout);
print "DTMF: $DTMF\n";

It works with 1und1 but not with our telephone system whereas Twinkle does.
Regarding the setup there is nothing special.
Connection to 1und1 is made per DSL and to the telephone sytem via LAN.
Twinkle and the perl script run on the same machine.

[noxxi]

Thanks for the details. Since you already have the code with debug running - code you please share the full debug output for a failing connection with at least debug level 40?

[fbrendel]

Here is the link to the log with debug level 40.
net-sip.log

[noxxi]

I cannot reproduce the issue when replaying the pcap data from the client in some test. It perfectly detects the DMTF sequence. Could you please rerun the test with debug level to 100, ideally with the version from 89f63b0 which adds more detailed debug output.

[fbrendel]

I'm on vacation this week, so I won't be able to test it until Monday.
I'll get back to you with the results then.

[fbrendel]

New log with debug level 100:
net-sip.log

[noxxi]

New log with debug level 100: net-sip.log

Thanks. Looks like I still need more debug info to understand why it fails. Could you please use 257f4d9 which adds more debugging to DTMF handling and create another log with debug level 100?

[fbrendel]

The new debug message doesn't appear in the output.
Do you still need the log?

[noxxi]

I think I've found the bug. Please check if ed072bb fixes the problem.

[fbrendel]

It works now.
Thank you! 😃

But make test throws a lot of errors now.

Files=27, Tests=1347, 398 wallclock secs ( 0.47 usr  0.05 sys + 76.61 cusr  3.52 csys = 80.65 CPU)
Result: FAIL
Failed 7/27 test programs. 13/1347 subtests failed.
make: *** [Makefile:979: test_dynamic] Fehler 255

see net-sip_test.log

[noxxi]

This fallout from the test is fixed. I've released a new Net::SIP version 0.836 which should fix your problem and pass all tests.