I have being using the summit X440-48P as edge switch. There are 3 different models of IP telephones which is connected directly to this switch are able to get the IP and are registered to its PBX in which PBX is located in the cloud. Only one model of IP telephone Cisco 8861 is able to make calls outside but when dialing internally with its other extensions the voice is not audible.
But when these phones are connected to a Cisco catalyst switch the same phones are working fine. The problems happens only when connecting to extreme switch.
Is there any extra commands need for enabling voice, specially for these kind of IP telephone.
I was planning to change the port speed from 1000mbps which is default to 100mbps. Can anyone send the command for changing the switch port speed and please mention if any body had this type of problem occurred and solution done for solving it.