Toa N-8000 Series - Manual (Page 608)

8-8
Chapter 8 APPENDIX
2.3. Unicast vs. Multicast Communications
When making paging calls via multiple exchanges, various kinds of interface units, or IP stations connected
to a network, either "unicast" or "multicast" may be selected as the communication method. For unicast
communications, separate data packets are created and sent individually to each destination IP address.
For multicast communications, however, a single data packet is transmitted to a special IP address, which
offers the advantage of allowing the communication band to be compressed. Note, however, that multicast
communications require routers and other networking equipment connected to the network (excluding non-
intelligent hubs and switches) that support appropriate protocols like the Internet Group Management Protocol
(IGMP) to enable packet transmission to special multicast addresses. The valid multicast address range for the
N-8000 System is from 225.0.0.0 to 238.255.255.255. (Some multicast addresses cannot be used. Refer to
p. 5-25 .)
• Consult your network administrator regarding the details of setting the multicast address, including confirming
whether or not such communications are possible.
To use the unicast method, the number of transmission source communication bands must equal the number
of transmission destination exchanges, various kinds of interface units, or IP stations.
N-8000EX (Z)
N-8000EX (B) N-8000EX (A)
(A) (B) (C)
Packet to N-8000EX (A)
N-8000MI (C)
Switching hub,
router, etc.
Packet to N-8000EX (B)
Packet to N-8000MI (C)
N-8000EX (Z)
N-8000EX (B) N-8000EX (A)
Packet to multicast
address (225.0.0.0
-238.255.255.255)
N-8000MI (C)
Switching hub,
router, etc.
[Unicast] [Multicast]
• Networking equipment
copy data and transmit
copied data.
(Multicast settings
need be performed for
routers, etc.).
• The number of transmission
source communication bands
must equal the number of trans-
mission destination exchanges.
2.4. Network Paging Restrictions
When performing unicast or multicast paging via a network, the numbers of paging destinations are restricted
as follows.
• Multicast Paging: Up to 191 destinations
• Unicast Paging: Up to 16 destinations for the exchanges, IP stations, and N- 8000MI,
and up to 8 destinations for various kinds of interface units.
• Multicast/Unicast Combined paging: Up to 191 destinations combined. However, Unicast paging is limited
to up to 15 destinations for the exchanges, IP stations, and N-8000MI,
and up to 7 destinations for various kinds of interface units.