one way audio for incoming calls

VOIP setup and troubleshooting
fosfet
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one way audio for incoming calls

Post by fosfet » Sun Apr 22, 2012 8:13 pm

After more than several years of near excellent voip service, in the last couple of weeks, a problem has developed with annoying regularity. For incoming calls, audio goes out, but there is nothing coming in. (I cannot hear the caller).

The ATA as an early linksys pap2. I limited the codec to G711a as per recommendations to resolve this same problem with xlite. Also tried xlite and it had the exact same problem.

The router is an ericson W 35 (3G). I removed and replaced the port forwards for 5060, which is what the pap 2 is using.

Can't help but think that there are forces outside of my house that are the cause of the new found unreliability.

Any ideas?

tim

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Dazzled
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Re: one way audio for incoming calls

Post by Dazzled » Sun Apr 22, 2012 10:15 pm

I haven't come across these routers before, so pending someone who knows them dropping in, I'm game to stick my neck out and say it's probably a router firewall problem. Firstly, does the PAP2 have a static address, so that forwarding always works? Second, normally once the UDP ports are forwarded, the RTP ports that actually carry the audio are automatically looked look after, but to make sure, arrange a one-way audio call (ATA or softphone) with router error logging set highish (say Warning). If the router is blocking traffic, it would normally log the event, including the ports (PROTO=zzz,SPT=xxx,DPT=yyy). The RTP ports used by the ATA are shown in the SIP settings.

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lodperera
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Re: one way audio for incoming calls

Post by lodperera » Mon Apr 23, 2012 9:10 am

Hi fosfet,

Please PM me your VoIP service number to check whether there are forces outside your wall creating this unreliability..

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jokiin
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Re: one way audio for incoming calls

Post by jokiin » Mon Apr 23, 2012 10:34 am

limiting it to a single codec would be the last thing I'd do with a PAP2

fosfet
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Re: one way audio for incoming calls

Post by fosfet » Mon Apr 23, 2012 5:58 pm

Hi Dazzled,

Your input is welcome regardless. The w35 is an excellent product. Only downside was the price, but maybe they are cheaper now.

1) Never did use a static ip as the router always assigns the same address.
2) Logs – good idea. Managed to perform a “problem” call. Nothing at listed for the warning section, nothing relevant for the all logs section.

I first thought router, which is why I replaced the port forwards. Which I don't think actually do anything, as I have the exact same issues with xlite (will sometimes work, and sometimes no incoming audio,and I have no port forwards set for the pc running that.

I have also disabled all the ALG's, including SIP. And the router does not consistently block the audio. To my simple brain, if the router was blocking the traffic then the phone would not ring at all, surely?

Given the long period of reliable and consistent service, I think the indications are for an external issue. When people call me back a couple of times, it starts working.

Lodperera; done.

Jokiin; yeah, service degenerated into general unacceptability. So that setting has been changed back.

Thanks all, tim

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Dazzled
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Re: one way audio for incoming calls

Post by Dazzled » Mon Apr 23, 2012 6:31 pm

Good luck with it then, it might be a wireless thing, if the logs show no "intrusions". The signal to ring the phone comes from Exetel on the forwarded port, and you can get this when audio is blocked. Audio is direct, on other ports, usually fairly high numbers, possibly 16384+. The PAP2 can tell you its setting under RTP Port.

The SIP rigmarole is designed amongst other things to allow the audio conversation to be set up despite having a router firewall.

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jokiin
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Re: one way audio for incoming calls

Post by jokiin » Mon Apr 23, 2012 8:09 pm

one way audio is quite often a NAT issue, would need to see screen shots of your current config to be able to offer any suggestions

fosfet
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Re: one way audio for incoming calls

Post by fosfet » Mon Apr 23, 2012 8:40 pm

Hi Jokiin, I think you will be disappointed:
nat_shot.png
nat_shot.png (92.21 KiB) Viewed 2952 times
Reading the manual before dinner, i see there is a much larger selection of tweakables available via some telnet interface that I currently have no knowledge/software/instructions for.

tim

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Dazzled
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Re: one way audio for incoming calls

Post by Dazzled » Mon Apr 23, 2012 9:18 pm

This looks interesting if you are inclined to poke around the internals ---- http://www.ericssonw35.com/pdf/W3xTechn ... iption.pdf

From that tome:
9.2 Command Line Interface
The CLI is mainly intended for operator service personnel handling tasks
like storing/exchanging configuration files and for maintenance purpose (i.e.
fault location and tracing).
Remote access to the CLI is possible using SSH2 and local access to the
CLI is provided through Telnet.
By default there are two accounts available for accessing the CLI:
• The operator (user-id operator), in addition to the end-user
privileges also is allowed to access allowed to access additional
WAN related configuration parameters, telephony service
parameters (W35 only), configuring the firewall, IPsec/VPN
termination, L2TP tunneling, CWMP and troubleshooting.
• An administrator account (user-id root), with full permissions.

9.3.1 Software Update
The Ericsson W3x runs Linux OS. The flash file system is formatted as two
partitions, each capable of holding a complete software image. If a software
update process should get interrupted, e.g. power failure during the update
process, there is always a last known good firmware image to boot from.
It goes on with some good news : You can log in as root. There is some CLI information. Note the warning though; 3 failed logins, and it ends the session.

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jokiin
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Re: one way audio for incoming calls

Post by jokiin » Mon Apr 23, 2012 9:54 pm

fosfet wrote:Hi Jokiin, I think you will be disappointed:
quite, I meant your PAP2 config, not your router

many times I've come up across the same scenario, I haven't changed anything on my end so it must be the VSP at fault, I understand the logic behind that thinking but I have seen many cases where the VSP or upstream provider has made some change that has required changes on the end users equipment to get things working again

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lodperera
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Re: one way audio for incoming calls

Post by lodperera » Tue Apr 24, 2012 9:50 am

Hi fosfet,

It seems to be an external force just like you and jokiin suspected. We are having the same issue when trying to recreate the scenario. :?

We are escalating this issue with our upstream carrier under Ticket ID: 5108687

Will keep you guys updated.

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Mort
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Re: one way audio for incoming calls

Post by Mort » Tue Apr 24, 2012 6:37 pm

I'm using a linksys SPA3102 which I believe has a lot in common with the PAP2. I remember having the same problem when I first set mine up that was fixed by a config setting. I can't remember what it was right now but I'll see if I can hunt it down.

The reason I suggest it though is due to a common theme... something that was working for a long time suddenly stops working for no apparent reason. In my experience the reason is "someone changed something". Could it be that the PAP2 was recently rebooted after a long uptime, and there was a working setting that hadn't been saved that was reset as a result?

I'm pretty sure it was people on these forums that helped me work it out, so if the old posts are still around and haven't been deleted/archived it should be easy enough to find.
As we know, there are known knowns. There are things we know we know. We also know there are known unknowns. That is to say we know there are some things we do not know. But there are also unknown unknowns, the ones we don't know we don't know.

fosfet
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Re: one way audio for incoming calls

Post by fosfet » Tue Apr 24, 2012 8:14 pm

Dazzled,
I'm up for some internal poking. The tech reference states I can check the signal strength of 3 transmitters at once. I find that irresistible. And good for antenna pointing. When I get the time I will check the Viking's website for the appropriate tool.

Jokkin,

Well that is funny. I have forgotten how to get an entire pap2 page onto a file that the website will accept. Meaning I think I have done it in the past, but at the moment I can only achieve the screenshot, not the entire scrollable webpage. Hopefully lodperera will fix it.

Mort,
I switch my router and ata and mobile phone off before I go to bed every night. And I never get woken by a phone call.

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Dazzled
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Re: one way audio for incoming calls

Post by Dazzled » Tue Apr 24, 2012 8:47 pm

I'm addicted to modem exploring - why they make them into puzzles I don't know. You only need a terminal/DOS prompt window. A scrolling terminal is better because you will probably finish up with many lines of output and you don't want it vanishing. Just telnet 192.168.1.1 to connect, then log in and off you go. Most modems suggest a help key at log in, usually ?. The help key may show a list of special purpose CLI config and status commands. quit ends the telnet session, but there may be a logout command as well.

IF you want to dig deep, the ultra-compact Linux systems have only a few utilities, rarely the ones you want, and a little ingenuity is needed to explore the operating system. ifconfig, cat /proc/version and cat /proc/meminfo usually work. echo * will hopefully give a list of the root directories. echo /bin/* may be useful. A Busybox shell might be installed, I don't know. Try echo ; exec /bin/sh (note the spaces). As long as you read/get/cat/echo rather than write/set you can't hurt anything. The layout is close to standard Linux, although un-needed system subdirectories are often omitted.

outbush
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Re: one way audio for incoming calls

Post by outbush » Wed Apr 25, 2012 8:46 am

fosfet wrote:After more than several years of near excellent voip service, in the last couple of weeks, a problem has developed with annoying regularity. For incoming calls, audio goes out, but there is nothing coming in. (I cannot hear the caller).
The ATA as an early linksys pap2. .............

tim
A couple of suggestions.
Most Linksys products use the RTP port range 16384 to 16482,
Have you tried port forwarding these ports to your ATA as well as the 5060 ports?

In your PAP2 configuration under provisioning
Do you have provisioning enable set to = NO?
If it is set to yes your ATA probably has picked up and loaded some different file settings causing you the audio problems.

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