delay when calling internally when in SRST mode
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02-12-2017 03:36 PM - edited 03-17-2019 09:30 AM
I have an issue that when I am in SRST mode all calls both internal and external calls take about 10 seconds to ring.
I have played with interdigit-timeouts but no luck.
Anyone had this issue or anyone have any thoughts?
It is a 2901 ISR router.
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02-12-2017 10:39 PM
Hi Mike,
Is the issue being seen with both SCCP and SIP phones? Are you trying to dial enbloc or digit by digit? Can you try configuring two DN's in a completely different range ( like if the existing DN's are 1XXX and 2XXX , theny try configuring 7XXX ) and assign them to IP phones and try calling between them to rule out any overlapping patterns. If the issue still persists then it will require checking the config and debug for a test call, preferably the simplest one like an internal call between two SCCP phones.
HTH
Manish
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02-13-2017 07:31 AM
Manish, thanks for the reply, I doubled checked and after a reboot it changes to "no digit collect kpml"
I set to digit collect and stays until a reboot. Any thoughts
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02-13-2017 10:21 AM
Post the config of SRST router and indicate the extension range for SRST phones.
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02-14-2017 03:16 PM
here you go

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02-13-2017 09:39 PM
This behavior looks to be an IOS related bug that i saw in a TAC SR some time back, i would suggest upgrading the IOS to latest on the 2901 and see if that helps.
Manish
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02-14-2017 09:42 AM
Manish, thanks I actually downloaded code last night. I did test with the digit collect on and it worked. I shut the isr down installed at customer site and it failed. the delay was back. i only had 15 mins so after looking at config i seen the no digit collect.
I am staging another site today so i can test and i will let you know
Thank you
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02-13-2017 09:48 PM
Hi Mike.
I think I can help you here. Are you using FQDN's for your CUCM hosts by any chance? If so, you are hitting this defect as I have been with 7841s.......
Another symptom of this bug is that when the phone is registered to SRST and there is no local DNS server available, outgoing SIP calls may be delayed by a few seconds if the phone is sending DNS requests at that time. We have observed a 5 to 10 second delay between the time the user dials a number and when ringing tone is heard.
No fix as of yet, we are going to use the following workaround but we haven't agreed an outage window yet with the customer, although Cisco TAC say it should work:-
The affected SIP phones can support 3 DNS servers, currently there are only configured for the two DNS servers that reside in each the primary and backup data centres respectively. If we made the 3rd DNS server the relevant local ISR/CUBE, and put in name resolutions for the three hostnames of the CUCM cluster
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01-15-2018 03:58 PM
Did you find the solution for this issue? I have the same problem.
