04-07-2009 01:40 AM
Hi,
I've noticed when there is no PSTN line terminated on FXO, still the dial-peer Operational status is shown as "UP". I've VIC2-4FXO where PSTN is terminated on two ports only. The dial-peers are configured for all 4 ports.
It is causing outbound calls hiting such dial-peer randomly and then falling-back to others. By the time call-reaches the working dial-peer, it seems the "timeout wait-release 3" is causing call failure.
I've shut down all such dial-peers and now everything works fine for me. I could've increased the timeout wait-release but curious to know if its a normal behavior of FXO ports.
I am trying to compare it with Dial-peers pointed to digital voice-ports (ISDN PRI), where when interface goes down, the dial-peers becomes OPERATIONAL DOWN.
I've Cisco 2811 running c2800nm-advipservicesk9-mz.124-11.T.bin.
Thanks,
inner_silence
04-07-2009 02:57 PM
Hi,
You need to think about the FXO port as if it was an analog phone.
When your phone is on hook, there isn't a reliable way of knowing whether the phone line is connected or not. This requires going off hook, checking for an off-hook voltage, and listening to dial tone.
The best practice for this scenario is to only configure dial peers that you know that are in use.
hth,
nick
04-08-2009 07:52 AM
Thanks for you reply Nick,
So you mean it is normal to see dial-peers pointing to Analog ports as always Operational UP?
Could you point me to some Doc highlighting this behavior? I did some research but couldn't locate one.
thanks,
inner_silence
04-08-2009 11:43 AM
Yes, it is normal. See:
http://www.cisco.com/en/US/tech/tk652/tk90/technologies_tech_note09186a008010e6d1.shtml
04-08-2009 08:24 PM
Hi Polo,
thanks for your inputs.
I went through this doc, it talks about only the digital voice-ports. I wanted to know how dial-peers operational status behaves when pointed to Analog voice-ports.
I think based on your's and Nick's comments, I can believe there is nothing wrong and DP pointing to analog voice-port always remains up. If I've access to I'll check it in some other scenarios as well may be with FXS/E&M ports this time.
Thanks to both of you for your time.
thanks,
innter_silence
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