Information Technology Reference
In-Depth Information
Figure 1.19
Tree-push streaming.
(a)
(b)
3
5
5
3
1
1
4
4
6
6
2
2
Figure 1.20
(a) Narada maintains an efficient mesh overlay among peers. (b) A source specific tree is built
atop this efficient mesh overlay afterward.
1.4.1.1 Narada
Narada [31] is one of the earliest ALM protocols. It is intended for multi-
source, multicasting. Narada is a mesh-first approach, that is, the main goal
of the protocol is to maintain an efficient mesh overlay. The multicast tree
is build atop this efficient mesh overlay. More specifically, when nodes have
media data to broadcast, a source specific multicast tree will be built based
on RPF. Even though Narada is very robust because of its mesh nature, it is
not designed for large groups due to the high overhead of maintaining the
underlying mesh overlay structure (see Figure 1.20).
1.4.1.2 NICE
NICE [40] arranges sets of end hosts into a hierarchy; the basic operations of
the protocol are to create and maintain the hierarchy. The hierarchy implic-
itly defines the multicast overlay data paths.
NICE minimizes the end-to-end delay between the leaders to their cluster
members by electing the leader as the center node of the cluster. The cluster size
is bound by [
k
, 3
k
-1], where
k
is a universal constant of this protocol. Clusters
