3Com 2500 manual 2 describes the fields in the cache display

Displaying the Multicast Cache 10-11

Table 10-2 describes the fields in the cache display.

Table 10-2 Information in the cache display

Field	Description
Origin	The source of the incoming packets. Entries preceded by an angle
	bracket (>) indicate a multicast subnetwork. Entries without an
	angle bracket, beneath the subnetwork entries, are multicast
	routers within that subnetwork.
Mcast-group	The destination multicast group
CTmr	Cache timer. The amount of time in seconds (s), minutes (m), and
	hours (h), that a cache entry has to remain in the cache
Age	Number of seconds (s), minutes (m), or hours (h) that the cache
	entry has existed.
PTmr	The time remaining, in seconds (s), minutes (m), or hours (h), before
	another prune will be sent to prune the Spanning Tree.
In-If	Interface number on which that gateway is connected. Traffic is
	expected to originate from this interface.
	T represents the tunnel; P denotes that a prune has been sent to
	this tunnel.
Out-If	Set of interfaces on which the traffic will be flooded out. I repre-
	sents the interface.