I have done a very rough sampling of traffic on the backbone IP traffic
this morning (9:30 am Fri 2 Aug 1996) using our sniffer.  Here are the
results based on 9036 ethernet frames:

	Protocol     # of frames      Percent

	  tcp		6432		71	
	  dns (udp)	2025		22
	  telnet	 813		 9
	  dns (tcp)	 431		 5
	  snmp		 372		 4
	  smtp		 180		 2
	  ftp		  21
	  ospf		  31
	  nfs		   6

The DNS zone transfers are performed using tcp. Most other queries are
udp. (Please note that I assumed that all of the udp traffic
was dns based. This seemed to be a reasonable assumption
based on the frames that I looked at.)

Doug Carson from network operations has the tools (RMON probes)
to do a much better job than this. He has indicated that 
he can do something with regard to IP protocol analysis
by the end of next week.