Our company uses phones GRP2604p and UCM6302, there are phones of other models, but the question specifically for this model.
Users complain about delays during the first seconds of call, and the voice delay is true there is about 1-3 seconds.
We began to collect packets on the PBX and found the problem that the PBX in communication with this model of phone reports “wrong sequence of numbers”, and gives great data loss and delays at start. The problems are observed in two directions from the PBX to the phone and from the phone to the PBX. With other models everything is normal, no delays and losses.
Can anyone suggest what is wrong, if the problem is in the settings, but they are the same for all models, or maybe there is a problem in the firmware of this model?