Single DN on Multiple Phones - Limit

[bjochims]

Is there an effective limit as to how many phones a single DN should appear on?  I have it successfully working on 10-15 phones but I have an application for a number to appear on 40 phones and I have significant issues when I attempt this.

[Jaime Valencia · Accepted solution]

AFAIK the limit is 300 shared line appearances per DN.

HTH

java

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[bjochims]

java - Thanks for the reply.  It appears that I must have some other issue then.  When I put the shared DN on 40 phones and call the number it takes 3-7 seconds before the caller hears ringing, another 2-5 seconds before the called phone starts ringing, and then you still can't answer the call.  Pressing the appropriate line button on the called phone does nothing.  I'll keep digging.   Thanks again!!

[Rob Huffman]

Hi Bob,

Java is most correct here is the actual reference;

Note: With CallManager 4.0 and later, 300 lines/phones can share the same DN.

http://www.cisco.com/en/US/products/sw/voicesw/ps556/products_tech_note09186a00801f3b4e.shtml

That being said, I've seen recommendations before that indicated issues exactly like what you are seeing when

more than 12-15 phones share the same line. If you provide your version we can have a look for bugs.

**Cisco recommends that the same value be configured for the maximum number of calls for all shared-line MCID devices.

http://cisco.biz/en/US/docs/voice_ip_comm/cucm/admin/8_0_2/ccmsys/a03dn.html#wp1100362

There is some other good info here;

http://cisco.iphelp.ru/doc/3/Cisco.Press.Cisco.CallManager.Fundamentals.A.Cisco.AVVID.Solution.2nd.Edition.Sep.2005.eBook-DDU/1587051923/ch03lev1sec2.html

Cheers!

Rob

[bjochims]

Rob,

Call manager is 7.1.3.33019-1.  All 40 phones are 7965's running SCCP45-8-5-3S firmware with (2) 7916 Expansion Modules.  There are 3 shared DN's on all of the phones and they all have Max Call = 4 and Busy Trigger = 1.   The first DN is configured to forward to the second on busy and the second DN forwards to the third on busy.  If all 3 are busy the caller should get a busy signal.

Thanks for your help!!  I am looking at the other information you referenced as well.

Regards,

Bob