I recently had a VIP user at my company complain that when he picks up an incoming call on his desk phone, the other party doesn't initially hear him and and initial "hello." After a ton of time trying to narrow down the issue to some signaling delay between the phones telling cucm they're off-hook, I found that the issue only happens when picking up the physical handset.
If I have the IP phone handset up to my ear and have my finger on the hook-switch and start talking (saying 1, 2, 3, 4) immediately after I release the hook-switch on an incoming call, the remote party only hears me say 2, 3, 4. At the same time, I can visibly see the call time not start counting until about .5-1 second after the hook-switch is released. Also, I can also tell when the audio is going to be sent because I don't hear any side tone while I'm speaking the "1."
At the same time, if the call is answered in any other possible way, things are perect:
- Pressing the soft phone "answer" button is immediate and 1, 2, 3, 4 is heard
- Pressing the physical "line" button is immediate and 1, 2, 3, 4 is heard
- Pressing the physical speakerphone button is immediate and 1, 2, 3, 4 is heard
- Pressing the physical headset button is immediate and 1, 2, 3, 4 is heard
Similarly, when simply picking up the handset, I see a noticeable delay between the line's status LED lighting up compare to tapping any physical buttons like the speaker phone.
I've been able to reproduce this on this CUCM deployment on 8861, 8851, 7861, 7975 and 7971 phones and I had a college at another company recreate it on his call manager as well. (And no, it's not related to http://www.nelsonet.net/wordpress/blog/2009/05/28/cisco-7941-and-7961-phone-handset-will-not-pick-up-or-answer as they're all brand new phones.)
Now this is being pretty picky as you'd need to pull the phone to your head extremely fast in order to have the first spoken word not be picked up to replicate the same behavior as holding your finger on the hook-switch, but this VIP user does just that.
After putting some thought into it, I could definitely see this delay being intentionally put in place to avoid the noise of the handset rattling around in the receiver while you're picking it up or to avoid any other noise that would occur while you're placing the phone to your head. That said I would hope that this would be a setting that is configurable on the phone or call manager.
Thanks,
Sean
