Choppy/Popping from the system recordings

Asterisk Asterisk Support
1

I am having issues with some choppy sound. Phone calls in or out over the iax trunks sound fine, but accessing the voicemail or auto attendent sound choppy sometimes.

ie. recording my unavialble message the first time was choppy, pressed 2 to re-record and this time it sounded fine?!?

I am not sure that the network is the issue here. My trixbox in on a small network, there is only 2 workstations and 2 servers, and 1 phone connected to a 100mb switch.

Only seems to happen when the system recordings are being played, ie Digital Receoptionist, or Voicemail…

I do not know where to look…

Is this something that jitter buffer can help with?

oh yea, the system is:
P4 1.6, 512MB Ram, 80gb 7200 HD, trixbox all up to date.
2 Zaptel cards installed, but not in use.
2 IAX trunks for in/out calls
currently only 1 bugetone 101 and 1 idefisk softphone.

2

make sure ztdummy is being loaded if you don’t load one of the zaptel cards - sound playback and conferencing require a timing source to play accurately.

3

ztdummy is loaded, and if I run zttest

[root@asterisk1 ~]# zttest
Opened pseudo zap interface, measuring accuracy…
99.987793% 99.987793% 99.987793% 99.987793% 99.987793% 99.987793% 99.987793%
99.987793% 99.987793% 99.987793% 99.987793% 99.987793% 99.987793% 99.987793%

I will get a few 100%'s in there…

4

hmmm…what version of zaptel?

how about IRQs? do an lspci -vb and post what IRQ’s everything is using.

5

[quote=“whoiswes”]hmmm…what version of zaptel?

how about IRQs? do an lspci -vb and post what IRQ’s everything is using.[/quote]

here is the output. Not sure though as I am not using the zaptel cards. Everything is IAX…

00:00.0 Host bridge: Intel Corporation 82845 845 (Brookdale) Chipset Host Bridge (rev 11)
Subsystem: ASUSTeK Computer Inc.: Unknown device 8088
Flags: bus master, fast devsel, latency 0
Memory at f8000000 (32-bit, prefetchable)
Capabilities: [e4] Vendor Specific Information
Capabilities: [a0] AGP version 2.0

00:01.0 PCI bridge: Intel Corporation 82845 845 (Brookdale) Chipset AGP Bridge (rev 11) (prog-if 00 [Normal decode])
Flags: bus master, 66Mhz, fast devsel, latency 64
Bus: primary=00, secondary=01, subordinate=01, sec-latency=0
Memory behind bridge: ed000000-eeefffff
Prefetchable memory behind bridge: eff00000-f7ffffff

00:1d.0 USB Controller: Intel Corporation 82801DB/DBL/DBM (ICH4/ICH4-L/ICH4-M) USB UHCI Controller #1 (rev 01) (prog-if 00 [UHCI])
Subsystem: ASUSTeK Computer Inc.: Unknown device 8089
Flags: bus master, medium devsel, latency 0, IRQ 11
I/O ports at d800

00:1d.1 USB Controller: Intel Corporation 82801DB/DBL/DBM (ICH4/ICH4-L/ICH4-M) USB UHCI Controller #2 (rev 01) (prog-if 00 [UHCI])
Subsystem: ASUSTeK Computer Inc.: Unknown device 8089
Flags: bus master, medium devsel, latency 0, IRQ 10
I/O ports at d400

00:1d.2 USB Controller: Intel Corporation 82801DB/DBL/DBM (ICH4/ICH4-L/ICH4-M) USB UHCI Controller #3 (rev 01) (prog-if 00 [UHCI])
Subsystem: ASUSTeK Computer Inc.: Unknown device 8089
Flags: bus master, medium devsel, latency 0, IRQ 4
I/O ports at d000

00:1e.0 PCI bridge: Intel Corporation 82801 PCI Bridge (rev 81) (prog-if 00 [Normal decode])
Flags: bus master, fast devsel, latency 0
Bus: primary=00, secondary=02, subordinate=02, sec-latency=32
I/O behind bridge: 0000b000-0000bfff
Memory behind bridge: eb000000-ec7fffff
Prefetchable memory behind bridge: eef00000-efefffff

00:1f.0 ISA bridge: Intel Corporation 82801DB/DBL (ICH4/ICH4-L) LPC Interface Bridge (rev 01)
Flags: bus master, medium devsel, latency 0

00:1f.1 IDE interface: Intel Corporation 82801DB (ICH4) IDE Controller (rev 01) (prog-if 8a [Master SecP PriP])
Subsystem: ASUSTeK Computer Inc.: Unknown device 8089
Flags: bus master, medium devsel, latency 0, IRQ 4
I/O ports at
I/O ports at
I/O ports at
I/O ports at
I/O ports at f000
Memory at 20000000 (32-bit, non-prefetchable)

00:1f.3 SMBus: Intel Corporation 82801DB/DBL/DBM (ICH4/ICH4-L/ICH4-M) SMBus Controller (rev 01)
Subsystem: ASUSTeK Computer Inc.: Unknown device 8089
Flags: medium devsel
I/O ports at e800

01:00.0 VGA compatible controller: nVidia Corporation NV11 [GeForce2 MX/MX 400] (rev a1) (prog-if 00 [VGA])
Subsystem: Elsa AG Gladiac MX
Flags: bus master, 66Mhz, medium devsel, latency 64, IRQ 11
Memory at ed000000 (32-bit, non-prefetchable)
Memory at f0000000 (32-bit, prefetchable)
Expansion ROM at efff0000 [disabled]
Capabilities: [60] Power Management version 2
Capabilities: [44] AGP version 2.0

02:09.0 Ethernet controller: Intel Corporation 82557/8/9 [Ethernet Pro 100] (rev 02)
Subsystem: Intel Corporation EtherExpress PRO/100B (TX)
Flags: bus master, medium devsel, latency 32, IRQ 255
Memory at ef000000 (32-bit, prefetchable)
I/O ports at b800
Memory at ec000000 (32-bit, non-prefetchable)

02:0c.0 Communication controller: Motorola Wildcard X100P
Subsystem: Motorola: Unknown device 0000
Flags: bus master, medium devsel, latency 32, IRQ 255
I/O ports at b400
Memory at eb800000 (32-bit, non-prefetchable)
Capabilities: [40] Power Management version 2

02:0e.0 Communication controller: Motorola Wildcard X100P
Subsystem: Motorola: Unknown device 0000
Flags: bus master, medium devsel, latency 32, IRQ 255
I/O ports at b000
Memory at eb000000 (32-bit, non-prefetchable)
Capabilities: [40] Power Management version 2

6

i changed the switch, uploaded new sound files in ulaw format… all to no avail…

Still have choppy sound from system recordings, and sometimes when recording (leaving) voicemail.

The in/out bound calls seem to sound fine, I am just having issues with recorded audio

7

Check the silence suppression. By default, asterisk has silence suppression. I don’t know if there’s a way to remove it from asterisk, I did it through my gateways…

Here is the link: voip-info.org/wiki/index.php … g+sip.conf

It is in the “SIP configurations - peers and clients” section:

Asterisk uses the incoming RTP Stream as a timing source for sending its outgoing Stream. If the incoming stream is interrupted due to silence suppression then musiconhold will be choppy. So in conclusion, you cannot use silence suppression. Make sure ALL SIP phones have disabled silence suppression. There is a solution for the silence suppression problem, see bug 5374 for details.

Hope it helps!

8

Yea, silence supression is turned off on the phone.
I am testing with another server, just built it last night.
I am getting the same cracks/pops consistantly.

I have noticed that if I use g726, the the cracks/pops are almost gone.
If I try ulaw, it will pop at the same place every time…
On this server, it is popping just before every word…
Dial *97 for voicemail…
Password <=sounds fine, then…
(pop)You (pop)have (pop)no (pop)megsgsges <=not misspelt that is how it sounds.
Then all the folowing is fine.

Hangup and do it again, exactally the same.

It will do this every time…

9

Experienced this.

Its definately a timiming issue, if you can not get your ztdummy working properly due to to MB problems it may be worth buying a single port FXO card from digium or sangoma.

This will fix your timing problem instantly.

10

Interesting, I have a Digium TDM400P and I still get these issues. I believe you 100% that it’s timing, but my Asterisk is definately seeing the card, how do I make sure it’s using it for timing.

11

Well, It appears that my timing issue was WITH my TDM400P, here’s the results of zttest:

— Results after 237 passes —

Best: 100.000000 – Worst: 91.613770 – Average: 99.483625

As you can see, there were significant drops in there that were causing my issues.

Digium will be getting an email about their cards.