Paging with IP Phones on the NEC SL2100

This Tech Tip covers the difference between multicast and unicast paging over NEC SL2100 IP phones.

Quick Tip

NEC SL2100 IP phones can receive pages via either multicast or unicast packets.

Unicast uses one DSP resource per receiving terminal.
Multicast uses one DSP resource for all terminals in the group.

However, multicast is unable to pass through subnets.

When using unicast packets, a DSP resource must be set to “Unicast Paging” for each phone in a paging group or packets will not reach all IP phones in the group.