[asterisk-users] DTMF not being sent ( RFC2833 )

[Edwin Lam]

i think i have similar problem after upgraded from 1.4.x to 1.6.2.17.
(originally upgraded to 1.8.3.2 unfortunately there were other more
pressing problems that forced me to downgraded it to 1.6.2.17)
i have a wanpipe device with 2 channels uses PRI signalling to PSTN &
the other 2 uses FXO signalling (connect to Rhino FXS channel bank).
the PRI part works fine but the FXO channels are having DTMF digits
skipped. i'm still trying to find out what's wrong with it.

On 4/23/11 8:48 AM, David wrote:
> Hello,
> I installed Asterisk 1.6.2.17.3 ( latest as of yesterday ) and had multiple
> problems with DTMF.
> I have two machines, we'll call them asterisk and asterisk-pri. Asterisk does IVR
> and asterisk-pri has a PRI card in it and connects to the PSTN. The two servers
> communicate via SIP with RFC2833.
> I setup logger.conf on both machines to display DTMF to the console. Both are
> built from source.
> Asterisk : spandsp, dahdi, asterisk.
> Asterisk-pri : spandsp, libpri, dahdi, asterisk wanpipe
> I eliminated AGI, hard phones, network et al by setting up this extension :
> exten => 22,1,Dial(SIP/114186939930 at pri1.omnity.net,30,D(132412983
> <mailto:SIP/114186939930 at pri1.omnity.net,30,D(132412983>#))
> in default.
> The only other non default setting is in sip.conf I added a outboundproxy ( which
> does NOT do RTP, only SIP ).
> I called asterisk from my hard phone ( gxp2000 ) by dialing 22.
> I see the console DTMF messages indicating the DTMF was sent or received. ( I
> forgot to keep this output ).
> I than watch the console DTMF output on asterisk-pri and it showed about half the
> DTMFs. The pager that was called showed the DTMFs that appeared on the
> asterisk-pri console.
> So somewhere between the two machines, the DTMFs have disappeared. So I ran
> TCPDump on asterisk and saw that close to half of the DTMF events were never sent.
> tcpdump -i eth0 -n -s 0 dst asterisk-pri-ip -vvv -w ~/dtmf.pcap
> I imported the file into wireshark on my local machine and confirmed that the dump
> almost matches what I saw on asterisk-pri.
> So, problem 1 : Asterisk is not sending all the DTMFs to asterisk-pri.
> I compared the packet scan to what I saw on asterisk-pri and noticed that between
> 1 and 3 dtmfs were missing.
> Problem 2 : Asterisk-pri loses some received DTMFs.
> I also noticed that some of the DTMFs coming out of asterisk had the wrong Event
> Duration. I had one DTMF with a duration of about 58000 ( I believe that's 58
> seconds ) but I only pressed the button for like 1/3 of a second.
> What I do not understand is that I in my final test last night was using asterisk
> 1.6 current with centos ( os that asterisk is developed on from my understanding )
> with all default settings ( excluding logger.conf, dialplan and outboundproxy )
> and I am having problems with the DTMF.
> Both servers were installed with CentOS 5.5 and were updated last night, after
> which I reinstalled asterisk. This did not resolve the issue.
> I am at wit's end and do not know where to go from here. I would really appreciate
> it if someone could give me some pointers on where to go next, what additionnal
> debugging steps I should perform. I would also really appreciate if someone could
> propose a solution.
> Please help!
> David
> Never give up, never surrender

-- 
Edwin Lam <edwin.lam at officegeneral.com>
Systems Engineer, OfficeWyze, Inc.
Ph: +1 415 439 4988 Fax: +1 415 283 3370
http://pgpkeys.mit.edu:11371/pks/lookup?op=get&search=0xD6506D20