Installing MacPPP --TCP/IP Access Over Serial Lines
University of Michigan
Merit Network, Inc.
June 1993
(c) 1993 by Merit Network, Inc. and The Regents of the
University of Michigan.
MacPPP was developed at, and is copyrighted by, the Merit
Network, Inc. and the University of Michigan. Merit and the
University of Michigan grant an unlimited license for use and
redistribution of the executable program provided that it is not
sold for profit, either as is or as part of another product.
Charges to recover the cost of duplication and distribution are
permitted. MacPPP is offered "as is"-neither Merit nor the
University of Michigan make any guarantees about the performance
or reliability of the software.
Acknowledgements
The PPP core software engine is based on public domain code
written by William Allen Simpson, taken from KA9Q. All
modifications to the PPP core software engine necessary to
develop MacPPP and bring the implementation to compliance with
RFCs 1331, 1332, and 1334 have been performed by Merit Network,
Inc. and the University of Michigan.
In recognition of his original work, William Allen Simpson has
been granted copyright for the PPP core software engine. The TCP
header compression routines used in MacPPP were written by Van
Jacobsen and are Copyright 1989 Regents of the University of
California. These routines were heavily modified by Katie
Stevens and William Allen Simpson.
Primary development of MacPPP at Merit Network, Inc. and the
University of Michigan was performed by Larry J. Blunk. Eric
Schneider wrote many of the "LAP" interface routines necessary
for a MacTCP mdev, as well as additional support code. Glenn
McGregor provided additional code, as well as valuable input on
the project. Many other individuals also provided input, and
their support is appreciated.
Table of Contents
Acknowledgements 3
1. About MacPPP
2. Getting Started
2.1 Copying MacPPP to Your Macintosh
2.2 Documentation
3. Configuration
3.1 Config PPP Control Panel
PPP Up/Down
Open/Close PPP
Statistics
Port Name
Idle Timeout
Echo Interval
Terminal Window
Hangup on Close
Tone/Pulse Dial
PPP Server
3.2 Configure Server Dialog Box
PPP Server Name
Port Speed
CTS (Clear To Send) Flow Control
Phone number
Modem Init
Modem connect timeout
3.3 Connect Script Dialog Box
Wait timeout
3.4 Authentication Dialog Box
Authorization ID and Password
Retries
Timeout
3. LCP and IPCP Options Dialog Boxes
4. MichNet Dial-in Numbers
1. About MacPPP
MacPPP is a Macintosh implementation of PPP, the Point-to-Point
Protocol, which allows you to use TCP/IP (Transmission Control
Protocol/Internet Protocol) over asynchronous serial lines.
MacPPP makes it possible for your Mac to act as a host on the
Internet, and, therefore, as a peer with other host computers
around the world. This means that you can use telnet, FTP,
Gopher and WAIS clients, and other services directly from your
Macintosh.
To use MacPPP, you must be dialing into a terminal server that
is capable of supporting PPP, such as a Merit/MichNet Secondary
Communications Processor.
MacPPP works with applications that use MacTCP, such as NCSA
Telnet and VersaTerm 4.6 and higher. MacTCP is Apple's control
panel device that provides a standard network interface for
TCP/IP applications.
MacPPP 1.1 is a Line Access Protocol (LAP mdev) driver for
MacTCP. This version does not support AppleTalk over PPP.
MacPPP requires MacTCP 1.1 or higher, Macintosh System 6.0.5 or
higher, and a Hayes-compatible modem for dial-in connections.
You can also use MacPPP over hardwired, asynchronous
connections, but the University of Michigan discourages the use
of these connections in favor of connections to Ethernet local
area networks.
Note that using the TCP/IP protocols adds a certain amount of
overhead to your communications sessions. The additional
overhead isn't a problem when you are working at higher
communications speeds, but may slow down communications
considerably with slower modems, or when you are using certain
software applications.
2. Getting Started
Once you have finished installing and configuring MacPPP, as
described below, your dial-in TCP/IP sessions will be handled
automatically. You'll simply click on the 'Open PPP' button on
the Config PPP Control Panel or start up a software application
that uses MacTCP. Your modem will dial automatically. You can
then enter your password and proceed with your dial-up session.
To configure MacPPP, you must change several settings on the
Config PPP control panel and the Configure Server dialog box. If
you are a MichNet user, you may also want to enter your
authorization code in the Authorization dialog box. All the
other settings are optional.
2.1 Copying MacPPP to Your Macintosh
MacPPP is available for anonymous FTP on the host merit.edu in
the file:
/pub/ppp/macppp1.1.hqx
This file is stored in an archived and compressed format, and
must be decompressed after you copy it to your Macintosh. The
file /mac/00introduction on the host mac.archive.umich.edu
explains how to decompress the file.
Once decompressed, MacPPP consists of a System Extension with
the filename 'PPP' and a control panel device with the filename
'Config PPP'. On System 7.0 machines, these files should go in
the Extensions and Control Panels folders, respectively. Once
you have opened the Config PPP control panel, MacPPP will create
a file called 'PPP Preferences' in the Preferences folder. The
PPP Preferences file is required for the PPP LAP driver.
On System 6.x machines, the 'PPP' and 'Config PPP' files should
go in the System folder. Once you have opened the Config PPP
control panel, MacPPP will create a file called 'PPP
Preferences' in the System folder.
After you have installed the system extension and the control
panel, reboot your machine.
2.2 Documentation
Two documentation files are included when you download the
file /pub/ppp/macppp1.1.hqx from merit.edu and decompress the
file. The first file, 'changes,' contains information on changes
included in the latest version of MacPPP. The second file,
/pub/ppp/macppp.txt, contains an ASCII (plain text) version of
the document you're reading now. A third file,
/pub/ppp/macppp.ps, contains a PostScript version of the
document you're reading now.
3. Configuration
Follow the steps below to configure MacPPP. Once you've
completed configuration, you can begin your PPP session either
by clicking on the 'Open PPP' button on the Config PPP Control
Panel or by launching an application that uses MacTCP.
1. On System 7.0 machines, select the MacTCP control panel icon
and click on 'More ...' On System 6.x machines, under the Apple
Menu, select 'Control Panel.' Then select MacTCP from the
control panel window, and click on 'More ...'
Set up MacTCP for server addressing by selecting "server" under
"Obtain Address". Do not select dynamic or manual (static)
addressing. In most cases, the local terminal server will assign
you a TCP/IP address. Click on the 'OK' button to save your
changes. You do not need to enter a gateway or TCP/IP address.
If for some reason you need to statically assign an IP address,
use MacPPP's IP Control Protocol (IPCP) option button on the
Configure Server dialog box. Note, however, that PPP will not
open the connection if the terminal server is not willing to
negotiate the address you have selected. In general, it is
preferable to let the terminal server provide the IP address by
leaving the address at the default setting, 0.0.0.0, in the IPCP
dialog box.
2. Select the PPP icon in the MacTCP control panel.
3. On System 7.0 machines, select the Config PPP control panel
icon. On System 6.x machines, under the Apple Menu, select
Config PPP from the control panel window to bring up the Config
PPP control panel.
3.1 Config PPP Control Panel
The Config PPP Control Panel leads to several dialog boxes and
windows that you'll use to configure MacPPP.
You can use the control panel to begin and end your PPP
sessions. The only parameters you need to set are the Port Name
and your phone type-tone dial or pulse dial. To enter the phone
number you want to dial, go to the Configure Server dialog box,
described in section 3.2.
Other parameters can also be used to customize MacPPP. These
optional settings are described below.
PPP Up/Down
This icon indicates the current state of the driver-more
specifically, the PPP IP Control Protocol. 'Open' indicates that
PPP is ready for IP traffic. 'Down' indicates that it is not yet
ready for TCP/IP traffic.
Open/Close PPP
Click on these buttons to open and close your PPP session, once
you've configured MacPPP.
Click on 'Close' to close your PPP session if you want to use
your serial port to run a traditional asynchronous program, such
as a terminal emulator. Click on 'Open' to manually re-open your
PPP session in order to use PPP again.
Statistics
When you click on this button, a dialog box with a set of
counters appears. Click on the Update button on the Statistics
dialog box to show the current value of the counters and the
current state of all supported PPP options. These options are
documented in the PPP RFCs (e.g., RFC 1331). The RFC (Request
for Comment) series is available for anonymous FTP on the host
nic.merit.edu in the /documents/rfc directory.
Most users will not need to use the Statistics dialog box.
Port Name
The Port Name pop-up menu allows you to select the modem port,
printer port, or any other serial ports registered with the
Communications Toolbox. (The Communications Toolbox is included
with System 7.0, and optional on System 6.x machines.) On some
Macintoshes with an internal modem, you'll only be presented
with an "internal modem" option on the pop-up menu.
The default is the modem port. If you have registered other
ports, MacPPP will use the Communications Toolbox to
automatically obtain their names and the names of associated
drivers.
Idle Timeout (minutes)
You can use the Idle Timeout pop-up menu to configure MacPPP so
that if your PPP session remains idle for a specified amount of
time, MacPPP will bring up an alert box asking you if you want
to close the session. You can either close the session or ignore
the message.
Leave the setting at None, the default, if you don't want to set
a timeout interval. If you want to set a timeout interval, click
on the pop-up menu and select a timeout interval from 5 to 120
minutes.
Echo Interval (seconds)
MacPPP uses a PPP packet called the "LCP (Line Control Protocol)
echo request" to determine if your connection has been dropped.
MacPPP sends the requests at the interval you specify; if the
terminal server does not respond after 3 successive requests,
MacPPP assumes that the link is down.
If you leave the Echo Interval pop-up menu set off-the
default-MacPPP will not send out any echo requests. If you want
MacPPP to send out echo requests, click on the pop-up menu to
specify the interval at which MacPPP should send out echo
requests-from 2 to 20 seconds.
Terminal Window
Click on this box to bring up a basic terminal emulator, which
will appear when MacPPP is connecting with the local terminal
server. You can then use the terminal emulator to manually type
any commands needed to put the terminal server into PPP mode.
Once you have entered these commands, click the 'OK' button to
start your PPP session.
If you click on the Terminal Window box, MacPPP will ignore the
Phone number and Modem init fields in the Configure Server and
Connect Script dialog boxes.
Currently, the terminal emulator offers only basic features, and
does not provide a cursor or scroll bar. Most users will not
need to use the MacPPP terminal emulator.
Hangup on Close
If this box is checked, MacPPP will send the modem a hangup
string (+++ ATH) when you close your PPP session.
Tone/Pulse Dial
Click on the 'Tone dial' or 'Pulse dial' button to select your
type of phone service.
PPP Server
See the next section for information on this feature.
3.2 Configure Server Dialog Box
Click on 'Configure server' in the Config PPP control panel to
display the Configure Server dialog box.
The only parameter you need to set on the Configure Server
dialog box are 'Phone number' and 'Port Speed.' If your modem
defaults are set up correctly, you can ignore the 'Modem Init'
field. If the defaults are not set up correctly, you'll need to
enter a modem initialization string, as described below. To
enter the information needed to identify you to the terminal
server, go to the Authentication dialog box, described in
section 3.4.
Several optional parameters can also be set on the Configure
Server dialog box. In the figure above, 'MichNet' has been
selected as the PPP Server Name. The port speed is 9600 bps, and
the phone number is MichNet's Ann Arbor 9600 bps dial-in number.
PPP Server Name
This convenient feature allows you to set up a separate
configuration for each host you access with MacPPP, assign a
name to that host, and connect to it by selecting its name on a
pop-up menu.
Click on the 'Add Server' button to add a new server. Next,
enter the server name-MichNet in the figure above-and configure
any desired options. The name will then be displayed in the PPP
Server box on the Config PPP control panel.
Once you've finished adding servers, you can connect to any of
them by clicking on the PPP Server pop-up menu on the Config PPP
control panel and selecting the host you want to access. MacPPP
will automatically establish a connection using the
configuration you specified.
Click on the 'Delete Server' option button to delete server
entries.
Port Speed
Enter the baud rate for the port being used for your PPP
session.
CTS (Clear To Send) Flow Control
Click on this box if you want MacPPP to use CTS for output flow
control. CTS flow control allows a modem to run at the higher
speeds provided by data compression. Your modem is responsible
for providing the CTS signal.
Currently, MacPPP does not support input flow control through
RTS or XON/XOFF. Be sure that your modem is not using XON/XOFF
flow control on input or output. If XON/XOFF flow control is
enabled by default, check your documentation and use the
appropriate modem initialization string in the Configure Server
dialog box to disable it.
Phone number
Click on this box to enter the phone number of the host you're
dialing. Several MichNet dial-in numbers are listed at the end
of this document.
Modem Init
Click on this box to enter any initialization strings required
by your modem. The string must be a Hayes 'AT' command. If your
modem defaults are set up correctly, you may not need to enter a
Modem Init string in order to use PPP.
The Modem Init string is typically used to:
Disable XON/XOFF flow control
Enable CTS flow control, if your modem supports it
MacPPP does not support XON/XOFF flow control. Be sure that your
modem is not using XON/XOFF flow control on input or output. If
XON/XOFF flow control is enabled by default, check your
documentation and enter the appropriate modem initialization
command in the Configure Server dialog box to disable it.
CTS flow control allows a modem to run at the higher speeds
provided by data compression. Your modem is responsible for
providing the CTS signal.
If you enter a Modem Init string but the phone number field is
not set (either because you are not using a modem, or prefer to
issue the dial command yourself), MacPPP will not send the Modem
Init command.
If the phone number field is set, MacPPP will automatically send
the initialization command 'AT E0V1' to the modem. This will
disable echoing and put the modem in verbose response mode. An
'OK' response is expected from the modem. If you have not
entered an additional modem initialization command in the Modem
Init box, the phone number will then be dialed.
If you have entered a modem initialization command in the Modem
Init box, the command will be sent to the modem after the 'AT
E0V1' command. MacPPP will again expect an 'OK' response from
the modem. After MacPPP receives an 'OK' response, the phone
number will be dialed. You may include any characters in the
phone number that your modem will accept, e.g., a comma (,) for
a pause between numbers.
Modem connect timeout
By default, MacPPP will wait up to 90 seconds for a response
from the modem before timing out. If it receives a CONNECT
response, MacPPP will proceed to the next phase. If a BUSY
response is received, MacPPP will attempt to redial. Click on
the Modem connect timeout box to change the timeout interval;
you can select any number of seconds.
Click on the option buttons on the bottom of the 'Configure
server' dialog box to bring up the Connect Script,
Authentication, and LCP/IPCP dialog boxes.
3.3 Connect Script Dialog Box
If you are dialing into a Merit/MichNet SCP, you do not need to
enter any information in the Connect Script dial box. The SCP
will automatically sense that you are initiating a PPP session;
you will not need to supply a 'PPP' string to the SCP.
If you prefer to use the Connect Script dialog box, you can
enter up to eight dialog strings to establish the connection.
All of these fields are optional. Once you've established a
connection, your modem and the terminal server will exchange
information contained in the dialog strings to initiate your PPP
session.
Select the Out button in front of the seven dialog strings to
indicate that your modem should send out the string. Select the
Wait button to indicate that the string is expected to be
received from the terminal server. Control characters can be
entered using the ^ (caret) convention, e.g., '^m' for a
carriage return. The <CR> check boxes indicate that a carriage
return should be appended to the end of the dialog string.
Placing a '^m' at the end of the string also appends a carriage
return to the end of the dialog string.
The backslash (\) is a reserved character in the Connect Script
dialog box. It can be used as follows for both Out and Wait
strings:
\r carriage return
\^ literal '^'
\\ literal '\'
\nnn 8-bit octal value
The following can be used only in Out strings:
\b send a break (100 milliseconds)
\d delay for one second
\t invoke the MacPPP terminal emulator
Wait timeout (seconds)
Click on this box to enter the number of seconds MacPPP will
wait for each 'wait' string to be received from the local
terminal server. The default is 40 seconds. By default, if more
than 40 seconds elapse, MacPPP will abort the attempt to
establish a connection. An alert box will appear, asking if you
want to quit MacPPP or retry the connect script from the
beginning.
3.4 Authentication Dialog Box
The only information you need to enter in the Authentication
dialog box is your authorization ID (authorization code).
Authorization ID and Password
Use the Authentication dialog box to enter the information
needed to identify you to the terminal server. If you have an
authorization code, enter it here. If you don't know what an
authorization code is, enter HELP at the Merit/MichNet "Which
Host?" prompt to access MichNet's free Online Help System.
Select 'ACCESS Information,' and then 'AUTHORIZATION server
information.'
Authorization codes comprise the host name, a forward slash, and
your userID. For example, if you are a user at Oakland
University and your userID is 1234, your authorization code
would be VELA/1234.
If you would like to obtain an authorization code, check with
the computing center at your institution to see if it can
provide one for you. If it cannot, send e-mail to
acctmgr@merit.edu or call the MichNet Accounts Manager at (313)
764-9430.
Merit/MichNet recommends that you do not enter your password in
the Authentication dialog box, even though your password will be
blanked. Instead, leave this box blank-you'll be prompted for
your password once you've connected to the local terminal
server.
Retries
Click on this box to specify how many times MacPPP should
attempt to resend your ID and/or password, if it is unable to
establish a connection with the local terminal server. The
default is 10 retries. By default, MacPPP will abort the attempt
to establish a connection after 10 retries.
Timeout (seconds)
Click on this box to enter the number of seconds MacPPP should
wait for the terminal server to respond to your ID and/or
password authentication request. You can enter any number of
seconds; the default is 3 seconds.
3.5 LCP and IPCP Options Dialog Boxes
The LCP (Line Control Protocol) and IPCP (IP Control Protocol)
Options dialog boxes allow you to configure the options that PPP
negotiates with the local terminal server. In most cases, the
defaults should work. Changing them is not recommended unless
you are familiar with several of the documents about PPP in the
Internet "Request for Comment" (RFC) series (RFC 1331, 1332, and
1334). The RFCs are available for anonymous FTP on the host
nic.merit.edu in the /documents/rfc directory.
4. MichNet Dial-in Numbers
You cannot use MacPPP on the current Ann Arbor 19,200 bps
dial-in lines. XON/XOFF is set on by default on these modems,
and MacPPP does not support XON/XOFF flow control.
Here are the Ann Arbor dial-in numbers that support PPP:
1200 bps (Bell 212A compatibles such as the Hayes smartmodem)
763-6520
2400 bps (V.22 bis compatibles) 764-4800
9600 bps (V.32 compatibles) 747-3400
MichNet's free Online Help System provides a complete listing of
MichNet access phone numbers. To access the help server, simply
enter HELP at the "Which Host?" prompt and select 'ACCESS
information.'