From:	MERC::"uunet!CRVAX.SRI.COM!RELAY-INFO-VAX" 20-OCT-1992 02:55:55.01
To:	info-vax@kl.sri.com
CC:	
Subj:	Re: NML and NICE

In article <1992Oct10.182913.26106@mercury.cair.du.edu>, toupine@casi.cba.du.edu (Ed Toupin) writes:
> I am looking for individuals who have experience with the NICE protocol.  

Yup, I've written lots of programs that communicate with NML via NICE, but
it is about 5 years ago now.

> I have a small application that is to collect statistical network information from
> several nodes.  I have reviewed the NICE manual from DEC and found it to be
> quite useful in explaining how to extract information using NICE.

I used the manual "AA-X437A-TK" and it was a pretty nice ;-) manual.

> My question is how to connect to the NML or do I communicate via NET0:?  I
> attempted to connect to NML and received a slew of errors.
> 
> Which device do I connect to?

It is a normal non-transparent DECnet connect that is to be performed.


	*  You connect (via $ASSIGN) to "_NET:" (not NET0:)

	*  Build an NCB which contains the name of the node 
	   you want to use executor and that specifies NML
	   as the object to connect to.
	   (<node>::"19=")

	*  Send this NCB to _NET: via a $QIO that specifies
	   IO$_ACCESS as function.
	   (What you send is really a struct which contains
	   the length of the NCB as a longword and the address
	   of the NCB)


Now the link is ready and you can communicate with the remote NML
via NICE.
This is pretty simple -just send a buffer that specifies the 
function you want to perform via $QIO specifying IO$_WRITEVBLK 
and read the with $QIO specifying IO$_READVBLK.

See the Networking Manual (System Management Volume 5A) for 
more info.

Note that the format of the message returned from NICE is not
static.
NICE returns a little header and then the information you requested
as a byte stream;


	+--+ <---+
	|  |     |
	+--+     =>  2 bytes, indicating type of info
	|  |     |
	+--+ <---+
	|  |     =>  1 byte, depicting length of info.
	+--+ <---+
	|  |     |
	+--+     |
	|  |     |
	+--+     |
	|  |     =>  n bytes of info
	+--+     |
	|  |     |
	.  .     .
	.  .     .
	.  .     .

	+--+ <---+
	|  |     |
	+--+     =>  2 bytes indicating next type of info
	|  |     |
	+--+ <---+
	|  |     =>  1 byte indicating lenght of next info.
	+--+ <---+
	|  |     |
	.  .     .
	.  .     .
	.  .     .


The data is not normally fixed length and the items included 
in a message depends on what as was requested and what the
remote NML found.

When you have written a set of routines to deal with this, you
will find that NICE works pretty well.
There is a lot of interesting functions that can be performed
by a program using NICE.

-- 

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