I have an avaya Ip500 running 4.1 software. All the IP 5621 are locking up when the user tries to use the Visual Voice Mail function. I upgraded the customer to 5.0.28 and the issue still remains. They do have some digital 5420 phones but those are not affected. Any idea's. Should we attempt further upgrades or is this a network issue?
Wiretek
Wiretek