8800 Series Phones experiencing delayed dialing internally/externally

[Edward Noell]

I have a single cluster environment running CUCM 11.5SU4 with a few thousand 8800 endpoints whether it be 8851, 8845, etc etc.  All of a sudden with the last 2 sites we have deployed we have some phones at each site consistently having a 5 or 6 second delay (35 other sites not reporting problem) before sending a call through while off-hook whether it be internal or PSTN bound. I say some phones because it doesn't occur on all phones but they all have the EXACT same CSS applied.  The phones experiencing the problem have it every time off-hook dialing occurs.

Our t.302 timer is set to 15 seconds and we have absolutely no overlap or ! in any dial patterns that would cause this delay.

I have tried a variety of firmware versions for the phones as well trying to correct the issue but no luck.  TAC keeps trying to blame the network but i can swap switchports with working phones and the issue follows the phone.

Anyone else having this issue with recently purchased phones possibly?  Any recommendations or bugs to reference?

[Dennis Mink]

I suggest you test this with a test route pattern, so for instance external number 1234567#. create a test RP for this and let the user dial it including the #, so it has an exact match. if it dials straight away with no delay, you know you have a problem with your dial plan, and its actually invoking the interdigit timeout

[Edward Noell]

i have essentially already tested this as everything being dialed is exclusive. there is nothing else to match it, i have two 8845s sitting side by side, even did a shared line so i am dialing from the same extension, same CSS etc.  Only thing different is ip address within the same subnet and MAC address.

Was thinking it was something weird with CUCM going on but the behavior is replicated in SRST mode.

[Dennis Mink]

so if you dial a number that has an exact pattern, even then the problem is there? and when dialling from one external extension to another?

[Edward Noell]

you got it right dennis.  For instance I have extension 81391 as a shared line on 2 phones.  From one phone i go off hook and dial 88888 and the call goes right through, go to the problem phone with the shared extension and exact same configuration and the call delays 5-6 seconds before going out.  Seems like phone is sending delayed signaling.

[Edward Noell]

even swapped switchports between the working and non working phone but the issue follows the phone

[Dennis Mink]

when you say "before going out" i am assuming you mean before the phone rings or at least before the caller heras a ringing tone.  sounds like a delayed 180 SIP ringing message, can you include SIP traces/debugs of a failed call including timestamps, so we can establish where the 5-6 seconds are lost.

thanks