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Call disconnects after one ring on Shared Line Directory Number

Mohnish Dhurve

Hello There

i am facing an issue that i have configured a shared line on 23 7942 Phones on Line 2. firmware version of Phone SCCP42.9-2-1S. CUCM version:

Now the issue is when i make a internal call to that shared DN after one ring the call is answered and gets disconnect. i am not getting this behavior. 

I check in the DN configuration for forwarding, Auto-Answer, max call and busy trigger all is correct.  No forwarding, Auto Answer is OFF, Max call & Busy trigger is 4 - 2.

Help me get this fixed.

10 Replies 10


Hi Mohnish,

Have you confirmed that there is no same extension in any other partition from route plan report ?

Do you see any of those 23 phones ringing when you say there is one ring and then the call disconnects ?



Hello Rajan

Thanks for Jumping in

No, there is no other phone rather that those 23, nor any Hunt pilot or any translation pattern configured. the dependency record for the DN shows only those 23 phones.

I am in India and the phones are in USA, but i configured the extension on a CIPC and yes the CIPC rings just once and then it disconnects.

Its worth checking whether you are hitting this defect from sdi traces :



I have run into this problem with 7942s (some 7962s but mostly 7942s) specifically; firmware version doesn't seem to matter. Since 7942s don't support sidecars, the bug referenced below may not apply in my situation. I have a couple of departments with shared lines on multiple phones (our CEO's office is one of them) who have this problem from time to time. I can always isolate the problem to one phone specifically. If I remove the shared line from the phones one phone at a time, I can always find the phone causing the problem. Once I find the phone, it doesn't matter what line is called on the phone, it drops the call after a 1/2 ring. I can reset the phone and sometimes that will clear the problem for a short period of time and most of the time it doesn't. When it doesn't, I try a factory reset. This doesn't work either. I've even tried replacing the hookswitch inside the phone and that doesn't solve the problem either. I have problems with the hookswitch in 7941/61s that cause disconnects. Once a phone gets in this condition, all I can do is replace the phone. Nothing seems to resolve the problem. When I'm working on the phone, it's laying in its back facing up so adjusting the footstand isn't a fix since the footstand is fully retracted.

Once I've exhausted all the troubleshooting, all I can do is replace the phone since it seems like it's internally defective somehow.


Hello Bill

Thanks. let me try to remove the shared line extension from the phone one by one and try to call. may be i can find the faulty phone.

Hi Bill,

I had seen this issue with 7942/7941 Model phone, if you have shared line on multiple phone that you will get this problem.


Example if you have 10 phone sharing single number 5449. if one of those 10 phones are not On hook correctly or timeout , then you will see this problem.

So you need to identify the one phone which is not correctly on hook , then correct it. Problem will get resolve and Shared number will start ringing.


When I asked TAC he said you cannot use single Shared number on multiple phones but we use same concept on 8945 and 8845 . Never had any problems


This behavior I noticed is with 7942 model phone.



I just had a same issue on 7962, ring once then it would hang up, the local tech ran through and hung up all the phones in the office and service was restored, thanks

Thank you Bill,
Try to find the parent fix, my understanding this phone will not work well with sharing number . TAC recommended to build hunt group instead of same number as sharing line on multiple phones.

Spot on, thank you.

Les Pruden

Hi Monish -


You note that all line appearances on all phones are configured as:


Max call & Busy trigger is 4 - 2


Set the maximum number of calls for all shared-lines devices to 2*N,
where N specifies the number of shared-line devices.

So ALL your 7942's should be set to max number of calls equals 46 (23 phones) and busy trigger equals 45 (please notice these values are NOT per type of phone or per shared line, these values are per individual phone).  
Give that a try.
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