See if this info helps;
Beep tone but no speech path is passed, when dialing the page access code.
The IP phones (DT700 series) are all installed on the same LAN.
Even though all the phones are on the local LAN, you MUST program a default Gateway into the IP terminal for internal paging to work.
NOTE: By default, the IP phones use Multi cast to send and receive internal paging. If the network you are on is blocking Multicast messages, then you can change the IP phones to use Unicast in 15-05-38. When the phones are set to Unicast, you will now be using extra DSP resources instead of just the one resource the Multi cast would have used.
The default Multicast address is 224.0.0.10 which could already be used by another device on the network. If you need to change this IP address, go to command 10-46-11 and assign a new Multicast address.