Multicasting in Myrinet

Hi Myri users, 
  Since the Myrinet switches are based on cross-bars, 
I was wondering whether it has support for multicasting
i.e. sending of a message to multiple destinations

As a first application of this feature, I needed it 
to monitor all the messages(packets) that traverse the 
switch. I know this monitoring feature in present in 
all 16-port Myrinet switches through an special Ethernet 
port but all I have is an 8-port switch (M2L-SW8). 

The current GM API (1.3.1) does not seem to provide function 
calls for multicasting. The gm_send_with_callback() function
provides for only point-to-point communication. 
Could someone let me know if there is any hidden function 
inside GM that supports multicasting or whether there has 
been any implementation of this feature elsewhere? 
If not, would an implementation of this feature require 
writing a new MCP? 

Thanks

Vijay
--
Architecture & Real-time Systems (ARTS) Lab,
310 Knowles Engineering Bldg,
UMass Amherst 01003
http://www.ecs.umass.edu/ece/realtime