IPTV successfully combines two established technology standards:
IP data addressing and transmission
IPTV system functionality makes use of
a variety of IT standards:
IGMP and PIM - IP Multicast protocols
for support of multicast streams
SAP: Session Announcement Protocol -
to announce active IPTV channel streams to network
SNMP: Simple Network Management Protocol -
for monitoring and control of network-attached devices
POE: Power over Ethernet - to provide power across the network to IPTV receivers.
IPTV uses multicast to reduce network bandwidth. Multicast protocols ensure that channels are only
to users that are actually viewing them.
Each channel stream is placed on
the network just once, and the packets making up the stream are
as necessary by the network switches. This minimizes data
overhead on the network.
To further reduce use of bandwidth in the network, a channel stream is not passed on to network
switches that have no end-users viewing the stream. In the
diagram below you can see that the
blue channel stream never reaches Switch D because there are
no viewers of this stream on Switch D.
IPTV uses two main Multicast protocols:
IGMP - Internet Group Management Protocol - supports
IPTV within individual VLAN's and Subnets
PIM - Protocol Independent Multicast - for routing
IPTV streams between different VLAN's and Subnets.
Multicast protocols significantly reduce the network bandwidth needed for supporting video streaming.
It is this technology that makes IPTV network friendly.