Denial events 1643 and 1644 - Attendant Console

[Valerie.M]

I have a user on an attendant console on some days complains that dialing is very slow. Often not all the digits register and she may have to dial two or three times before the call goes through. This occurs even when she's only dialing a 4-digit extension, presumeably when she's transferring a call.

Here's a sample list trace:

12:49:57 hold attendant 4100 cid 0x1f52
12:49:57 hear moh port 01B15001
12:49:57 xoip: faxff modemff ttyff 10.20.99.250:2050 (igc)
12:49:57 xoip: faxff modemff ttyff 10.20.99.150:33204 (igc)
12:49:58 active attendant 4100 cid 0x1f6e
12:50:06 dial 412# (she was dialing 4142; not sure if she actually hit the # key or if the phone made a mistake here, skipped the 4 and inserted the #)
12:50:06 denial attendant 4100 cid 0x1f6e
12:50:08 idle attendant 4100 cid 0x1f6e
12:50:11 idle attendant 4100 cid 0x1f6e
12:50:11 split attendant 4100 cid 0x1f6e
12:50:11 denial event 1644: Orig block/invalid digits D1=0x20002 D2=0x1f70
12:50:11 active attendant 4100 cid 0x1f70
12:50:11 denial event 1643: Off-hook dialing time out D1=0x20002 D2=0x1f6e
12:50:11 denial attendant 4100 cid 0x1f6e
12:50:11 split attendant 4100 cid 0x1f6e
12:50:14 idle attendant 4100 cid 0x1f6e
12:50:15 split attendant 4100 cid 0x1f6e
12:50:15 denial event 1644: Orig block/invalid digits D1=0x20002 D2=0x1f71
12:50:15 active attendant 4100 cid 0x1f71
12:50:15 denial event 1643: Off-hook dialing time out D1=0x20002 D2=0x1f6e
12:50:15 denial attendant 4100 cid 0x1f6e
12:50:15 split attendant 4100 cid 0x1f6e
12:50:17 idle attendant 4100 cid 0x1f6e
12:50:22 dial 4142
12:50:22 ring station 4142 cid 0x1f6e

This is an intermittent issue. It may occur two or three days during a month.

Any ideas?

Thanks!