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MNP10.TXT
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1993-06-02
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MNP-10 explanations, discussions, and beyond.
NOTE: This file includes information collected and condensed from many
sources. Supra's sole intent in providing this file is to inform
user's of what MNP-10 is and what it is not.
MNP10.TXT Rev 1.0 (PHM 6/2/93) from Supra BBS (503)967-2444
Supra's Technical Support department has been contacted by many users
either confused or curious about the MNP-10 protocol and what it is able to do
for them. The information provided in this file should assist modem user's in
grasping an unbiased view of MNP-10's benefits and shortcomings. A brief look
into CDPD is also provided at the end of this document to put MNP-10 into a
more precise light in regard to other available advanced protocols.
********* MNP10 **********
Condensed Supra's CompuServe Area (Fm: Stephen Satchell 70007,3351)
First, MNP-10 is also known as ACE, or Adverse Channel Enhancement. If the
communication channel or connection changes characteristics significantly, the
protocol will rebuild the data connection, possibly changing modulation methods
in order to effect the repair. So a connection running V.32 modulation might,
when something really hash happens on the line, might be recovered by reverting
to a 2400-bps V.22 bis connection. Also, if the connection starts out bad and
gets better, ACE will increase the speed until you reach the maximum practical
speed for the channel you have.
That's what it does. Note that ACE reacts to CHANNEL CHANGES. While this used
to be a problem on the Public Switched Telephone Network (PSTN) the widespread
installing of digital transmission means that changes don't happen because of
the inter-exchange network. Local networks are also going digital, so the
changes during a call simply don't happen. (This also negates the reason for
having fall-forward and fallback in V.32 bis.)
"So MNP-10 becomes a useless appendage for wireline calls. Cellular calls are
another story, since each second can bring a whole new connection..."
****
Citation: Newsbytes, Dec 11, 1992 pNEW12110013
------------------------------------------------------------------------------
Title: Microcom maintains MNP 10 works best for cellular. (Microcom
Inc.'s MNP 10 error correction system for cellular networks)
Authors: Blankenhorn, Dana
------------------------------------------------------------------------------
Reference #: A13083837
==============================================================================
Full Text COPYRIGHT Newsbytes Inc. 1992
..omitted..
Spokesman David Powers told Newsbytes that a number of US companies are also
looking at MNP 10, in the same way as Bell Canada, and his company will soon
name names. He also discussed why the system is preferable to V.42, the wired
standard for error correction and compression at 9,600 bits/second, and
V.42bis, which extends the same system up to 14,400 bits/second.
"The advantage of MNP 10 over V.42 is fundamental," he said. "It can set-up a
call, or perform the handshake, at 1200 bits/second upgrade the speed to
14,400, stay at that level as the connection allows, downgrade to slower
speeds as conditions become noisy, and then unlike other schemes, upgrade the
speed again. Most other modems will downgrade in a noisy environment, then
stay there for the duration. MNP 10 gives you the most efficient transmission
possible."
..omitted..
****
Citation: Newsbytes, Dec 10, 1992 pNEW12100017
------------------------------------------------------------------------------
Title: Bell Canada launches MNP-10 trial on cellular net. (three-month
trial of data transmission protocol)
Authors: Buckler, Grant
------------------------------------------------------------------------------
Reference #: A13088059
==============================================================================
Full Text COPYRIGHT Newsbytes Inc. 1992
..omitted..
Introduced at the beginning of 1991, MNP-10 is a data transmission protocol
designed to minimize errors while getting the best possible performance out of
modems, according to Microcom. Its key feature is the ability not only to slow
down to a lower transmission speed when line quality is poor, but to speed up
again if the connection improves. Most modems will slow down in response to a
poor connection, but cannot resume a higher speed.
The ability to shift speed both up and down makes MNP-10 well suited to
cellular transmission, where the quality of a connection may vary as the
mobile unit moves around. MNP-10 can also cope with the glitches caused as the
cellular system "hands- off" calls from one cellular transceiver to the next,
Powers said.
..omitted..
****
Citation: MacWEEK, Jan 27, 1992 v6 n4 p18(1)
------------------------------------------------------------------------------
Title: Data, voice go on air with combo. (Mitsubishi International Corp.
and Microcom Inc. to co-market Cellular Data Link cellular
telephone with built-in modem) (Gateways) (Product Announcement)
Authors: Welch, Nathalie
------------------------------------------------------------------------------
Subjects: Product Introduction; Marketing Agreements; Telephones; Modems
Integrated Voice/Data
Companies: Mitsubishi International Corp._Marketing
Microcom Inc. (Norwood, Massachusetts)_Marketing
Products: Microcom MNP-10 (Modem)_Marketing
Microcom Cellular Data Link (Cellular communications
equipment)_Product introduction
Reference #: A11884117
==============================================================================
Full Text COPYRIGHT Coastal Associates Publishing L.P. 1992
..omitted..
MNP 10's Adverse Channel Enhancements regulate modulation and data packet size
to optimize throughput across the poor quality connections frequently
experienced with cellular systems.
..omitted..
****
Citation: MacWEEK, March 8, 1993 v7 n10 p18(1)
------------------------------------------------------------------------------
Title: Rockwell adds MNP Level 10 to chip sets. (Rockwell International
Corp.) (MNP 10 adverse-channel protocol) (Gateways: Briefs)
(Brief Article)
------------------------------------------------------------------------------
Subjects: Enhancements; Chip Sets; Cooperative Agreements; Protocol
Companies: Rockwell International Corp._Product enhancement
Microcom Inc. (Norwood, Massachusetts)_Product development
Reference #: A13497616
==============================================================================
Full Text COPYRIGHT Coastal Associates Publishing L.P. 1993
Rockwell adds MNP Level 10 to chip sets
Newport Beach, Calif. - Rockwell International Corp. last month began offering
MNP Level 10 as a standard feature in all its high-speed V.32 and V.32bis
data, fax and voice chip sets. Rockwell chips form the technology base for
many third-party modems.
MNP 10, called an adverse-channel protocol, enhances modem communications over
cellular links and poor-quality land lines. Rockwell previously offered the
protocol as a standard feature in its V.22bis devices and as an option in its
V.32 and V.32bis products.
In addition, Microcom Inc. of Norwood, Mass., the developer of MNP Level 10,
and Rockwell have agreed to develop protocol extensions for new modem
technologies, such as adaptive line probing, which are anticipated to result
from the creation of the V.Fast standard in late 1993.
Rockwell International Corp.'s Digital Communications Division is at 4311
Jamboree Road, P.O. Box C, Newport Beach, Calif. 92658-8902. Phone (714)
833-4600; fax (714) 833-4078.
****
Citation: MacWEEK, Sept 10, 1991 v5 n30 p24(1)
------------------------------------------------------------------------------
Title: Microcom ships first Mac MNP 10 modem. (Microcom Inc.'s
QX/4232bis 14.4K-bps data modem uses the company's MNP 10
error-correcting protocol)(includes a related article on
Microcom's role in setting modem standards) (product
announcement)
Authors: Wylie, Margie
------------------------------------------------------------------------------
Subjects: Product Introduction; Modems; Error-Correcting Codes; Protocol
Transmission Speed; Enhancements; New Technique
Companies: Microcom Inc. (Norwood, Massachusetts)_Product introduction
Products: Microcom QX/4232bis (Modem)_Product introduction
Reference #: A11278095
==============================================================================
Full Text COPYRIGHT Coastal Associates Publishing L.P. 1991
By Margie Wylie
Norwood, Mass. -- Microcom Inc. earlier this month announced and shipped the
first Mac-compatible modem to use the company's super error-correcting
protocol, MNP 10.
The $999 QX/4232bis is a 14.4-Kbps data modem that uses public standard
V.32bis and V.42bis data-compression protocols to speed transmissions to up to
38.4 Kbps.
Using Microcom's latest error-correction protocol, MNP 10, the modem is
designed to overcome the harsh telephone-line conditions of overseas calls or
even cellular connections, according to Microcom. The error-correcting
protocol will automatically speed up or slow down data transmissions as
connection conditions fluctuate (see story, below).
Like all modems that use specialized compression or error- correction
protocols, the MNP 10 modem requires a connection with another MNP 10 modem to
take full advantage of the higher speeds, throughput and reliability offered
by the protocol. It will, however, communicate with any modem that uses the
V.42bis protocol, according to Microcom.
The QX/4232bis is not the first MNP 10 modem, but it is the first external
modem that works with Macs and IBM PCs and compatibles. Newport Beach,
Calif.-based Rockwell International Corp. earlier this year shipped an
internal modem with MNP 10 for PCs.
Microcom Inc. is at 500 River Ridge Drive, Norwood, Mass. 02062-5028. Phone
(617) 551-1000; fax (617) 551-1007.
If you've ever wondered what the alphabet soup of standards surrounding modems
is all about, just ask Microcom.
The company began developing the now ubiquitous MNP (Microcom Network
Protocol) modem standards nearly 10 years ago. Now, it mingles its technology
with public standards while continuing to develop higher-level services.
MNP levels 1 through 4, error-correction protocols, are now part of the public
domain and have been integrated into the Consultative Committee International
Telegraph and Telephone's V.42 modem standard. The standards boost a modem's
throughput to up to 38.4 Kbps.
MNP 5 through 7 provide data compression and are compatible with the CCITT
standard V.42bis.
MNP 6, 9 and 10 offer "extended services" that build on the lower-level
standards.
MNP 10, the most sophisticated of the standards yet, will adapt packet sizes
and data speeds dynamically to accommodate fluctuating line conditions that
would break other modem connections.
FROM A LONG ARTICLE ON MODEM STANDARDS:
Lousy Connections
While MNP 2-4 amounts to little more than a frill, a newer MNP error-control
protocol called MNP 10 is well worth having if you send data by cellular or
other very poor connections. Of course, the modems at both ends of the
connection must support MNP 10. MNP 10 has four components, the first two of
which are modifications of standard CCITT handshake operations.
The first--negotiated speed upshift--attempts to establish a connection at the
modem's slowest speed and moves higher until the highest reliable speed is
found. This virtually guarantees that a connection will be established. CCITT
handshakes do the reverse, sometimes making it impossible to make a connection
in the first place. The second--robust auto reliable--makes multiple attempts
to overcome channel interference during the handshake sequence before giving
up.
Once a connection is made, MNP 10 uses a technique called aggressive adaptive
packet assembly to find the ideal data packet size--somewhere between 8 and
256 bytes. CCITT protocols start with the highest packet size and reduce it
progressively, an inefficient process on a poor line. MNP 10 does the reverse.
Finally, MNP 10's dynamic speed shift allows both modems to upshift or
downshift the transmission rate as phone lines improve or deteriorate. CCITT
V.32bis modems offer speed negotiation as well--but only when two V.32bis
modems are involved.
********** CDPD **********
Condensed from Supra's CompuServe Area (Fm: Stephen Satchell 70007,3351)
There is some discussion in the cellular community that the V-series protocols
may not be suitable for cellular transmission. The CDPD (Cellular Digital
Packet Data) people felt that pure QAM is not suitable for radio-based
tranmission. They use a different protocol for the CDPD data, which permits
9600-bps operation over analog cell channels (full duplex) with some immunity
to RF-based impairments and cellular-specific impairments. In particular, the
modulation scheme would be "cell-switch aware" so that the data output could be
clamped and data input stopped before a cell-switch occurred, and everything
opened up again after the switch is completed.
****
Citation: PC Magazine, Oct 27, 1992 v11 n18 p130(2)
------------------------------------------------------------------------------
Title: Lap lines: making connections with wired and wireless options.
(Subnotebook Communications)(includes related article on pros and
cons of different technologies) (Cover Story)
Authors: Reiter, Alan A.
------------------------------------------------------------------------------
Subjects: Notebook Computers; Data Communications; Wireless Networks;
Local Area Networks; Modems
Reference #: A12746087
==============================================================================
Abstract: A variety of data communications options are available to users of
the new generation of 'subnotebook' portable computers. Subnotebook
computers do not have dedicated modem slots, instead using internal
PCMCIA-slot modems or external modems connected to serial ports.
Small external modems cost $150 to $500 and provide 2,400- to
14,400-bps communications; V.42 and V.42bis protocols are common for
error control and data compression, along with MNP 5. Some new
modems use cellular radio networks for wireless connections.
Wireless data communications equipment remains bulky, expensive and
less than reliable in many situations. Most of the US is covered by
cellular service, but the modem must have an error-control protocol,
and a cable for linking a standard modem to a cellular phone can
cost as much as $300. Packet radio is an emerging
wireless-communication technology that is available today and works
better than cellular technology for short distances. Paging networks
offer cost-effective one-way data communications and are small,
inexpensive and require far less power than two-way systems.
==============================================================================
Full Text COPYRIGHT Ziff-Davis Publishing Company 1992
Making connections with wired and wireless options.
..omitted..
Modems provide an alphabet soup of protocols, most notably V.42 error control
and V.42bis data compression of up to 4 to 1, as well as the earlier MNP 5
data compression and error control scheme. Microcom (Norwood, Massachusetts;
617-551-1000) promotes its MNP 10 protocol as being specifically designed for
communicating over cellular networks.
If you intend to attempt cellular communications, hedge your bets and get a
modem that handles V.42/V.42bis and MNP 10. To further complicate matters, an
"enhanced" V.42 protocol incorporating most of the features of MNP 10 is under
development, says Ken Krechmer, principal of Action Consulting, who
specializes in telecommunications standards issues.
..omitted..
CELLULAR, PACKET RADIO
If you want to send and receive data outside the office without a wired
(phone) connection, you will be on the "bleeding" edge of technology: The
equipment is bulky, balky, and expensive. Your choices today are cellular
phones and packet radios.
Cellular service covers much of the U.S. with varying degrees of reliability.
To make the connection, you will need four pieces of hardware: your
subnotebook computer, a modem, a thick interface cable, and a cellular phone.
You'll get better coverage in remote areas with a bulky 3-watt in-car
transportable phone than with a 0.6-watt portable unit. The modem needs an
error-control protocol: V.42/V.42bis, Telebit PEP (Packetized Ensemble
Protocol), or Microcom MNP 10. The cable can cost $300; it goes between the
modem and phone and makes the modem think it's attached to a regular phone.
The best-known is the Axsys cable, from Spectrum Information Technologies
(Dallas, Texas; 214-630-9825). By next year, the smarts in the interface
cables may be built into modems.
With a good connection, it is possible to get throughput of 5,000 to 10,000
bps. Speed is important because connect time costs 20 to 50 cents a minute.
The second form of ready-today wireless two-way communication outside the
office is packet radio. For reliability and shorter messages such as
dispatching applications, packet radio beats cellular hands down. Ardis, a
partnership between IBM and Motorola, uses Motorola's over-the-air
packet-radio protocol (Lincolnshire, Illinois; 708-913-1215). RAM Mobile Data,
a business venture of RAM Broadcasting and BellSouth Enterprises, uses the
Ericsson/Swedish Telecom Mobitex protocol (New York, New York; 212-373-1930).
Typical bills on either network ranges from $40 to $120 per month.
One of the most anticipated developments is the introduction of the Cellular
Digital Packet Data (CDPD) service, developed by IBM and McCaw Cellular
Communications. By overlaying packetdata techniques on today's analog
cellular systems, data is supposed to be transmitted at 19,200 bps. CDPD is
an important interim step between today's hit-and-miss analog cellular
connections and the all-digital cellular network likely to become a commercial
service (in a few areas only) in 1993. (New cellular phones will be both
digital and analog, since the switch-over from analog service will take many
years.)
CDPD is a nonproprietary protocol that may be used by any cellular carrier
when it becomes available in 1993. For CDPD, you will need to buy a special
modem; these should be available in several versions, ranging from external
portable devices to internal modems incorporated in cellular phones.
..omitted..
********** End of File **********