Xref: utzoo comp.sys.ibm.pc:23465 comp.dcom.modems:3254 comp.sources.wanted:6073
Path: utzoo!utgpu!watmath!softart!ashok
From: ashok@softart.UUCP (Ashok C. Patel)
Newsgroups: comp.sys.ibm.pc,comp.dcom.modems,comp.sources.wanted
Subject: Re: request: MNP
Message-ID: <49@softart.UUCP>
Date: 19 Jan 89 03:39:04 GMT
References: <948@taurus.BITNET> <14@rsoft.UUCP> <3903@alvin.mcnc.org>
Organization: Softart Microsystems Inc., Waterloo Ont. Canada
Lines: 37

> The level of MNP refers to exactly what process it is
> performing.
> I can summarize the classes as follows:
> Class 3 - error correction only
> Class 4 - Data Framing (basically turns async to sync)
> Class 5 - Data Compression (2:1)
> Class 6 - Data Compression (3:1)

Not quite right.  MNP classes are as follows:

Class 1 - error correction using an async half duplex method.  That is
          only one side can send at a given time. (For half duplex modems)
Class 2 - error correction using an async full duplex method.  Same as the
          half duplex protocol but both sides can send at the same time.
Class 3 - error correction using a synchronous full duplex method.  The
          framing technique here is SDLC.
Class 4 - optimization of the packet overheads.  This can be run with any
          of Classes 1-3.  It just reduces the packet overheads.
Class 5 - data compression (2:1).  It can be run with any of Classes 1-4.
Class 6 - "ping pong".  Meant to be used with a 9600 baud half duplex (9600bps
          one way only) using the Rockwell 9600 baud FT modem chipset;
          the channel is used alternately by each side.
Class 7 - data compression (3:1).  A better form of data compression than
          Class 5.  It can be used instead of Class 5.
Class 8 - Protocol enhancements.  This is brand new.  I don't have many
          details for this.

How do I know this?  I write MNP firmware for a *lot* of modem manufacturers
for use inside their modem products.

> 
> Bruce Felstein    | MicroElectronic Center of North Carolina
> felstein@mcnc.org | The views expressed are my own

---------------------------
Ashok C. Patel
Softart Microsystems Inc.