Unicast/Multicast Paging Mode; Figure 1-41 Multicast Mode Example - NEC SL1000 Features And Specifications Manual

SL1000/SL1100
Description
IP Terminals can now receive an Internal Page via a Unicast or Multicast packet based upon system
programming. This feature allows IP Terminals to be assigned to Unicast Mode, Multicast Mode, or
Auto.
When the phone is set to Unicast Mode the internal paging is sent to the phone via a Unicast Packet.
When the phone is set to Multicast Mode the internal page is sent to the phone via a Multicast
U
Packet.
When the phone is set to Auto, the internal page is sent to the phone either by Multicast or Unicast
based on the subnet of the IP station. If the terminal is in the same subnet as the VoIPDB then it will
receive the Internal Page via a Multicast Packet. If the terminal is in a different subnet than the
VoIPDB the IP Terminals will receive the Internal Page via a Unicast Packet.
When phones are set to receive Unicast packets the VoIPDB will send a separate RTP stream to each
phone that is set to receive the page. E.g. If there are five IP Terminals in the page group and they are
all set to Unicast Page Mode the VoIPDB will send five separate RTP streams utilizing five DSP
resources.
When the phones are set to receive Multicast packets the VoIPDB will send one RTP stream.
Multicast is a protocol that allows one device to communicate to multiple devices without the need to
stream to the individual end point. E.g. If there are five IP Terminals in the page group that are set to
Multicast Mode, the VoIPDB will send one RTP stream utilizing only one DSP resource.
1-706

Unicast/Multicast Paging Mode

Paging Group
IP
Multicast
or
VoIPDB
ESI
TDM

Figure 1-41 Multicast Mode Example

IP
IP
IP
Subnet 1
IP
Subnet 2
Multicast packet Relay function
is required to relay the multicast
packet of paging.
Unicast/Multicast Paging Mode
ISSUE 2.0
Mode: Multicast
Mode: Multicast
Mode: Multicast
Mode: Multicast